Improving Low Electrical Current Measurements

Characterizing devices at low current levels requires knowledge, skill, and the right test equipment. Even with all three, achieving accuracy in these measurements can be a challenge because the current level is often at or below the noise level of the test setup. To ensure measurement accuracy, it is important to know the type of test equipment to use, the different sources of measurement error, and the appropriate techniques to minimize these errors. Examining several test examples, such as characterization of a field-effect transistor (FET) and a carbon nanotube, can help in the learning process.

The term low current is relative, of course. A current level considered low for one application, such as 1mA, may be high for a device operating at 10nA. In general, an instrument’s noise level will establish its low-level sensitivity, with low current measurements referring to those made near an instrument’s noise level. Trends in portable and remote electronic devices, along with advances in semiconductors and nanotechnology, are requiring greater use of low current measurements. Small geometry devices, photovoltaic devices, and carbon nanotubes (CNTs) are a few examples of devices designed to operate at extremely low current levels, and all of these devices must be characterized in terms of their current-voltage characteristics (I-V measurements).

A number of instruments are available for low-current measurements, depending on the type of device under test (DUT) and the level of current to be measured. Perhaps the most ubiquitous tool on production lines and in field service is the digital multimeter (DMM), which typically provides capabilities for measuring current, voltage, resistance, and temperature. The range of commercial products is wide, from low-cost units with 3½-digit readout resolution to rack-mount and benchtop high precision laboratory units. The most sensitive DMMs available can measure current levels as low as about 10pA.

When greater precision is needed, various forms of ammeters are available to measure current. These can be as simple as older types that measure current flow from the mechanical deflection of a coil in a magnetic field. More modern digital ammeters use an analog-to-digital converter (ADC) to measure the voltage across a shunt resistor and then determine and display the current from that reading. Newer picoammeters typically use a feedback resistor, which allows more accuracy in current measurements at such low levels. They are available in various configurations, including high-speed models and logarithmic units capable of measuring a wide range of currents. While they are extremely versatile, it is useful to understand the performance limitations of feedback ammeters.

Feedback Ammeter Performance. A simple feedback ammeter can be modeled with a small number of parameters. The current source is modeled as a voltage source in series with a parallel RC circuit, i.e., the source resistance (RS) and parallel source capacitance (CS). The feedback ammeter is modeled as a feedback amplifier with a parallel RC feedback circuit across it (i.e., RF and CF), with the two amplifier inputs being the external current source and the internal voltage noise source, VNOISE. The capacitances in the source and measurement circuits are parasitic elements associated with the resistances and circuit wiring. Using this model and ignoring capacitance, the noise gain of the ammeter circuit can be found from:

Output Voltage Noise = (Input Voltage Noise) x (1 + RF/RS)

As this equation implies, the output of a feedback ammeter circuit is a voltage, which is proportional to the input current. As the source resistance decreases in value, the output noise increases. When RF = RS, the input noise is multiplied by a factor of 2. If the source resistance is too low, it can have a detrimental effect on the noise performance of the measurement system. The optimum source resistance is a function of required measurement range for an ammeter, with a minimum value of 1MegOhm to measure nanoamps of current, compared to a minimum value of 1GigOhm to measure picoamps of current.

However, source capacitance can also affect the noise performance of a low current measurement instrument. In general, as the source capacitance increases, the noise gain also increases. This means that the equation above should be modified by substituting the feedback impedance (ZF) for the feedback resistance (RF) and the source impedance (ZS) for the source resistance (RS).

Additional current measurement instruments include electrometers and source-measure units (SMUs). An electrometer is essentially a voltmeter with a high input impedance (1TOhm and higher) that can be used to measure low current levels. It can be used as an ammeter to measure low current levels even at low voltages, and can also be used as a voltmeter to make voltage measurements with minimal effect on the circuit being measured. As an ammeter, an electrometer can measure currents as low as the instrument’s input offset current, as low as 1fA in some cases. As a voltmeter, an electrometer can measure the voltage on a capacitor without significantly discharging the device, and can measure the potential of piezoelectric crystals and high-impedance pH electrodes.

The SMU is an innovation for making low-current measurements. It combines precision current sources and voltage sources with sensitive detection circuitry for measuring both current and voltage. An SMU can simultaneously provide a source of current and measure voltage or provide a source of voltage and measure current. A well-equipped SMU may include a voltage source, current source, ammeter, voltmeter, and ohmmeter and is also programmable for use in automatic-test-equipment (ATE) systems.

Minimizing External Noise. All of these measuring instruments are effective tools for measuring current, but their sensitivity to low levels of current will be limited mainly by sources of noise, both within and external to the instrument. The DUT also affects the level of current that can be accurately measured with a given instrument, because the DUT’s source resistance (RS) establishes the level of Johnson current noise (IJ), which is low-level noise caused by temperature effects on electrons in a conductor. Johnson noise, which can be expressed in terms of either current or voltage, is essentially the voltage noise of a device divided by the device resistance:
IJ= (4kTB/RS) / RS,
where k = Boltzmann’s constant (1.38 × 10–23 J/K),
T = Absolute temperature of the source (in ºK),
B = the noise bandwidth (in Hz), and
RS = the resistance of the source (in ohms).

Both temperature and noise bandwidth affect the Johnson current noise. A reduction in either parameter will also reduce the Johnson current noise. Cryogenic cooling, for example, is often used to reduce noise in amplifiers and other circuits but adds cost and complexity. The noise bandwidth can be reduced by filtering, but this will result in slowing the measurement speed. The Johnson current noise also decreases as the DUT’s source resistance decreases, but this is not often a practical or even possible option.

Ideally, a current measurement would be just that of the DUT source. However, current noise from various unwanted sources can make it difficult to read a low-level DUT source current. One of these unwanted sources is part of the measurement system itself, i.e., the coaxial cables used to interconnect test instruments to each other or to the DUT. Typical test cables can generate as much as tens of nanoamps of current as a result of the triboelectric effect. This occurs when the outer shield of a coaxial test cable rubs against the cable’s insulation when the cable is flexed. As a result, electrons are stripped from the insulation, and added to the current total. In some applications, such as nanotechnology and semiconductor research, the current generated by this effect may exceed the level of current to be measured from the DUT.

Triboelectric effects can be minimized by using low-noise cable, with an inner insulator of polyethylene coated with graphite underneath the outer shield. The graphite reduces friction, and provides a path for the displaced electrons to return to their original locations, eliminating random electron motion and their contribution to the additional noise level. Excess current flow from triboelectric effects can also be minimized by reducing the length of the test cables as much as possible. The test setup should be isolated from vibration to minimize unwanted movement of the test cables, by positioning test cables on top of vibration-absorbing material, such as foam rubber. Test cable movement can also be minimized by taping the cables to a stable surface, such as the test bench.

Piezoelectric effect is another source of error in low-current measurements. It causes spurious current generation due to mechanical stress on susceptible materials. The effect varies by material, although some materials commonly used in electronic systems, such as polytetrafluoroethylene (PTFE) dielectrics, can produce a relatively large amount of current for a given amount of stress and vibration. Ceramic materials are less affected by piezoelectric effects and produce lower current levels. To minimize current generated by this effect, it is critical to minimize mechanical stress on insulators and construct the low-current test system using insulating materials with minimal piezoelectric properties.

Insulators can also degrade low-current measurement accuracy by means of dielectric absorption. This phenomenon occurs when a high-enough voltage across an insulator causes positive and negative charges to polarize. When the voltage is removed from the insulator, it gives up the separated charges as a decaying current, which is added to the total amount measured during a test. The decay time for the current from dielectric absorption to dissipate can be from minutes to hours. The effect can be minimized by applying only low-voltage levels to insulators used for low-current measurements.

Insulators can also degrade low-current measurement accuracy due to contamination from salt, moisture, oil, or even fingerprints on the surface of the insulator. Contamination effects can also plague printed circuit boards in a test fixture or in the test setup when, for example, excessive flux is used when soldering. On an insulator, the contamination acts to form a low-current battery at a sensitive current node within the insulator, generating noise currents that can be on the order of nanoamps. To minimize measurement errors from insulator contamination, an operator should wear gloves when handling insulators or simply avoid touching them. The use of solder should be minimized, and solder areas should be cleaned with an appropriate solvent, such as isopropyl alcohol. A clean cotton swab should be used for every cleaning, and cotton swabs should never be reused or dipped into the cleaning solution after having been used for cleaning.

It is critical to make low-current measurements in the absence of magnetic fields, because such fields can induce current flow in conductors. This is typically due to variations in magnetic field intensity, or motion of a conductor within a magnetic field. Both cases should be avoided to maintain measurement accuracy, which is best accomplished by properly shielding the measuring instrument or system.

Minimizing Instrument Offset Current. An instrument used for low-current measurements should show a zero reading when its input terminals are left in an open-circuit condition. Unfortunately, this is rarely the case due to a small current known as the input offset current. It is caused by bias currents of active devices in measuring instrument circuitry, as well as leakage current through insulators in the instrument or test system. Most instrument manufacturers specify the input offset current on their products’ data sheets for comparison purposes, and this small amount of current must be taken into account in any low-current measurement. In other words, the instrument’s reading is actually the sum of the DUT source current and the instrument’s input offset current.

The input offset current can be found by capping the input connector and selecting the lowest current range available on the measuring instrument. The reading shown by the instrument, after it has properly settled to a stable value, should be within the specification shown on the instrument’s data sheet and can be subtracted from DUT readings. On some instruments, a current-suppression function can partially null input offset current.

Another way to subtract input offset current from a low-current measurement is to use a relative function found on some measuring equipment, such as ammeters. The relative function stores the reading of whatever residual offset current is being measured with the input terminals left in an open-circuit condition; this reading is treated as the zero point for subsequent readings.

Application Examples. Some examples of practical low-current measurements include characterization of field effect transistors (FETs) and CNT devices. A more common FET test involves evaluation of a device’s common-source characteristics. Even at low current levels, the drain current can be studied using a simple test setup with a two-channel SMU, such as the Keithley Series 2600A System SourceMeter instrument. A two-channel SMU has the capability to source current or voltage and measure current or voltage simultaneously. To characterize a FET, it is mounted in a test fixture that allows secure ground and bias connections. One SMU channel supplies a swept gate-source voltage (VGS) to the FET while the other supplies a swept drain-source voltage (VDS) and measures the FET’s drain current (ID). This simple test setup allows the measurement of drain currents as low as 10nA or less.

Electronic materials such as photovoltaic wafers and CNT sheets are typically characterized in terms of their current density—the amount of current they can generate for a given area of material. Researchers from South Korea’s Seoul National University, conduct such tests to evaluate multi-walled carbon nanotube (MWNT) devices fabricated on an arc-discharge CNT substrate using a Keithley Model 6517 electrometer [1]. In these studies, current densities as low as 10–4/cm2 were measured at applied electric fields of 5V/¼m and less. Practical analysis of the I-V characteristics of CNT-based electronics can also be performed in a manner similar to that for the FET by using a pair of SMUs to sweep drain and gate voltages while measuring and plotting the drain current as a function of gate voltage.

The required resolution and accuracy of low-current measurements will dictate the type of measurement tool used. When accuracy is less of an issue, a basic DMM may suffice. But for more demanding requirements, a precision electrometer or SMU may be needed. These precision instruments are optimized for low-current measurements, providing measurement resolution as small as 1fA. More techniques and tips on low current measurements are contained in Keithley’s Low Level Measurements Handbook [2].

Electric Fishing Reel Maintenance

The invention of the electric fishing reel was one of the greatest innovations in fishing. It has leveled the playing field so that anyone wanting to fish no matter their size, gender, skill, or age can fish anywhere and for anything they want. You can still experience the thrill of the catch without having to manually turn the crank. You still need to understand the nuances of fishing in general and the type of fishing you are trying to catch. But, it is a lot easier and a lot more fun with an electric fishing reel.

The electric fishing reel has been one of the greatest inventions in modern hobby and sport fishing. They are fantastic for fisherman of all levels and ages. They are liberating and allow fishing for types of fish that some would not normally pursue. But, you have to keep those reels clean and in shape or they will malfunction, or outright break. Maintaining electric reels is a simple prospect and does not differ much from maintaining a normal reel. Follow these simple eight steps and you will be able to maintain your electric reel in pristine condition, so it can be used for years to come.

1. Make sure you are always using the correct voltage to power the reel. Some reels can be powered by either a cord or a battery make sure you use the type outlined in the manufacturers annual.

2. After you are through with an electric reel, same as with a spinner reel, you should wash it thoroughly with light soapy water solution. The electrical parts are sealed so you should not have to worry about getting them wet. Your goal is to remove salt, dirt and other grim that may have accumulated during use. You should not use harsh chemicals; such as, gasoline, kerosene, benzene as these chemicals may break down the resin on the reel.

3. With most models it is unnecessary to clean the housing that holds the electrical parts. In fact it is suggested that the housing not be opened to reduce the possibility of damaging the gaskets that seal and protect the electrical parts.

4. The level winder mechanism need frequent lubrication with either silicone grease or vegetable grease. This helps keep winding of the fishing line smooth. It also helps avoid bunching and tangling of the line caused by the line catching as it is being wound.

5. Special care should be taken when storing your electric reel. It should be stored with the lever pooled back so the spool is free. The helps protect against the clutch plate from locking after being stored for a long period of time. A locked or stiff clutch plate will be difficult to loosen and spool later.

6. Special care should be taken of the plug, plug sockets, and clips and batteries. You should clean and dry thoroughly. then apply silicone grease or vegetable grease to the plug to keep corrosion down. It is essential that you follow manufacturer directions for these items.

7. regular maintenance of the reel is essential to its proper operation. One thing you should remember to do is to apply either silicone grease or vegetable grease to the gears inside of the spool and other parts. Using grease other than silicone grease or vegetable grease could cause cracks in the resin.

8. If the reel needs to be overhauled use a trained professional. There are special gaskets inside the reel that protect the electrical parts and damaging these gaskets could reduce the expected life of the reel.

Most Common Problems With Automobile Electrical System

An integrated part of any vehicle, the automobile electrical system has definitely made driving a lot more easier over the decades. Frequent innovations in electrical system has helped us in a comfortable and easy drive. But friends, no coin comes with a single side. If there are advantages, there are problems or hassles that accompany them. Very often, you face problems while starting up your car and notice other problems with the electrical system. Are you aware of the problems that actually affect your electrical system. Some of the hassles that you face with your vehicle's electrical system are:

Common Automobile Electrical System Problems Are :

Car's Battery Is Dead - This is the most common problem. Your car's battery might be dead, thus inviting troubles for your vehicle.

No Power Stored in the Battery – This is possible that your car's battery does not have ample power so that it can spin the engine.

Alternator is Not Working – At times, a damaged alternator might be the cause for the hassle. Such an alternator will not charge the battery.

Problem with Starter or Solenoid – These bad auto parts will affect the functioning of a braking system.

Battery Cables Might Be The Problem – A loose cable might be the root of the problem.

Electrical Fuses – If there are any damaged electrical fuse or loose wire, it might affect the smooth functioning of electrical system.

Cracks In Alternator Belt – Tension as well as crack in the alternator belt causes trouble.

Ignition System Has Problems – Thats common in breakdown of a vehicle. Any auto part of automobile ignition system like ignition switch, magento, coil wire, etc might have caused the problem.

Loose Spark Plugs – These electrical devices have loosened or are not properly implanted into internal combustion engine.

Modern Innovations In Electric Underfloor Heating Systems

Underfloor heating may sound a new innovative advancement but in reality, this system was discovered back in the ancient times by the Romans. This concept has been followed and modified to give rise to new equipment that is called electrical under-floor heating system.

With the help of this incredible mechanism, we can keep our homes warm and cosy. You must be wondering about the sky-high prices but this is not the case because now every household can conveniently afford this latest equipment. The system operates effectively by heating the floors of the entire home and once the floor is heated, the rest of the house automatically gets warmer too.

Electric underfloor heating systems operate in the simplest ways. I would suggest that you fix electric underfloor heating system when your house is being constructed in order to evade all the hassles associated with the installation, once the house is constructed.

All you have to do is to lay down a set of hollow metal tubes on the ground. On top of the metal tubes, an extra layer of flooring will be laid down, which is the final flooring of your entire house. The metal pipes are connected to electrical switches via wire and plug.

As soon as you will switch on the electrical socket, the power will run through the metal tubes and produce heat. This production of heat warms up the upper floor which in turn gives the entire house a comfortable and cosy feel.

Electric underfloor heating systems are extremely cost efficient and can be effectively used during the winter season, when there is a cold draft chilling everything. The whole mechanism consumes very little electricity thus saving great deal of money in electricity bills. Moreover, the system traps the heat between the pipe and the ground and as a result, the floor retains its warmth for a longer period of time even after being switched off.

By now, you might be eager to delve into further information regarding this amazing equipment. Let me tell you, electric under-floor heating not only lowers down the electricity bills but with the help of proper heating insulation, your savings can be increased further.

If you place a thick layer of good insulating material between the metal pipes and the floor then the heat can be greatly prevented from escaping back into the ground. This helps to keep the floor warmer for longer time periods and you will not have to run the system throughout the night.

Modern Residential Electrical Systems And Innovations

Residential electricians in Calgary see safety, innovation and efficiency as key elements in home building and renovation. Of course, it is no secret that residential electrical systems are much more efficient and safe than they once were. With the current trends toward sustainability and conservation, Calgary electricians are also seeing increased innovations in this area.

While modern wiring is well-known for being much safer than old 60-amp electrical service or knob and tube wiring, one thing that has not been improved until very recently is the design of wall outlets. They older style of outlet poses a grave threat to young children. A recent innovation that is currently making waves in the Calgary electrician industry is the move toward tamper .

The simple yet clever design of these receptacles is so effective in preventing injuries and burns that are a result of the natural curiosity of young children that the new National Electrical Code has made them a requirement in all new and renovated dwellings. Residential electricians in Calgary can provide further information on how to obtain these receptacles, and can even install them for you.

Another innovation, and one that the environmentally conscious will be particularly interested in, is energy efficient light fixtures. Calgary electricians are seeing a rapidly increasing popularity in this type of light fixture, just as they are with other types of larger energy efficient appliances. These fixtures, which are almost the standard in new home building, have many advantages over older, less efficient models. Most obviously, they use less energy than traditional fixtures, thereby reducing the amount of greenhouse gases that are sent into the atmosphere as well as saving the homeowner money. But residential electricians in Calgary are quick to point out the other advantages, such as the more even light distribution, and the hundreds of choices in decorative styles and features such as dimmers, timers and motion sensors.

Of course, if you are going to invest in energy efficient light fixtures, most Calgary electricians will suggest that you also use the newer style of energy efficient light bulb, also known as LED lights. These lights have many advantages over the older style of bulb. For one, they are longer lasting (up to ten times!). Secondly, they are more durable, standing up better to bumping and jarring. A third advantage is that no mercury is used in their manufacturing…and of course they are more efficient, using less electricity thereby making them more cost effective and putting more money in your pocket. While residential electricians in Calgary don’t necessarily participate in the selection and installation of light bulbs, they will be able to answer any questions you might have about them.

These are, of course, just a few of the innovations made in modern day electrical systems, but there are many, many more. Calgary electricians will be able inform you, and help find and install all kinds of interesting and innovative electrical systems and appliances in your home.

Electrical Panel Design Software

Generates: Generates data sheets as bill of materials. estimation & costing. GA drawings, Farication drawings, Bus-Bar chart, Cut-out (Mechanical) design. Auto-generation - single line diagrame (SLD).

Electrical Panel Design Software - Industrial Power Control
(3 phase, 50/60 Hz electrical system, LT industrial power & control panel design)

One Software with multiple design features:
a)- Design Motor Control Center (MCC)
b)- Design Power Control Center (PCC)
c)- Design Desk Type Panels
d)- Design Instrumentation Panels
e)- Design Distribution & Metering DBs
f)- Design Feeder Pillars
g)- Design Bus Bar Trunking
h)- Draw Schematic Electrical Circuits

Simple operation: No intensive training. Just select the required switchgear, drag it to the workarea and drop.
Automatic Panel Sizing: What ever switchgear ( ACB, OCB, SFU of any make) is added to the template, automatic panel size & dimensions, panel volume, MS / SS sheet weight is calculated.
Automatic Busbar Sizing & Weight: Calculates bus bar size, cross-section & weight automatically as per the selected incomer size and taking into consideration other factors affecting the size and performance of busbars.
Electrical Symbol Library: Built in electrical symbol libray. Select a symbol and place it on the e-board. Draw as sophisticated electrical circuits as you can.
Multifunction: Design any type of electrical control panel, instrumentation panel, draw electrical circuits and calculate automatic bus bar size. Mouse click wiring numbering in auto ascending mode. Auto Labelling of all electrical acceessories.
Multi-color Wiring Diagrams: Give different colors to phase & neutral lines and make your electrical drawings more easily understandable and presentable.
Generates: Generates data sheets as bill of materials. estimation & costing. GA drawings, Farication drawings, Bus-Bar chart, Cut-out (Mechanical) design. Auto-generation - single line diagrame (SLD).
A key design tool: A key design tool for electrical panel designers, electrical panel manufactures, electrical machine builders, electrical engineering professionals, electrical switchgear manufacturer, electrical suppliers, electrical design consultants, electrical contractors.
CNC compatible Programming Text File: It generates text file to feed input details to CNC sheet cutting machine for making cut-outs for accessories. Text file contains programming for 2 - axis CNC co ordinates.

Latest Update -
1 - Now design PCC, MCC, Distribution Centers, Distribution Boards, Machine Control Panels using PLCs, Instrumentation Panels, Desk Type Panels, Floor Type (slanted) Panels, Floor Type (plain) Panels.
2 - Get General Layout Drawings, Bill of Materials sheet, Estimation & Costing sheet, Single Line Diagrams, Complete Circuit Diagrams (semi automatic) generation.
3 - Labeling System (for accessories and controls) Added,
4 - Wiring (ferrule) Numbering System Added,
5 - Motor Starter Star - Delta Drawings added and auto selection of materials as per motor capacity and many more...

Know more about the software...

Electrical Control Panel Design Software
3 phase industrial power control panel and distribution board designing is no more a tedious and time consuming job now. Get your industrial power panel and distribution board designed within minutes. Just drag the required switchgears, instruments, meters, indicating lamps, fuses & accessories into your work area and let your computer simulator design and calculate the various dimensions of your panel for you. Make changes in size if required, change placement of items to best suit you and again get a new design and dimension. No limit how many times you change the layout and you get the final designs.Simulator takes care of various clearances while you place an item in the template and calculates the final size by taking into consideration these clearances and other factors.

Panel accessories
Panel accessories like - Voltmeter, Ampere meter, Frequency meter, Red Indicator, Yelow Indicator, Blue Indicator, Hinge, Lock, Knob, Contactor, Relay, Timer, Insulator, Busbar - Support, Selector Switch, Control Fuse, Push Button, Earth Fault Relay, Over Current Relay, CT, Electric Motor Starter, Power Factor Meter can be dragged from the tool bar and placed upon the panel template as per the need of the design.

Types Of Panels You Can Design
With the help of this software now you can design any type of 3 phase industrial power and electrical control panels - be it a power control centre (PCC), a motor control centre (MCC), an electrical power distribution centre, electrical distribution board or an instrumentation panel. Design cubical power panels, desk type control and instrumentation panels, floor type control and instrumentation panels. A key tool to design 'Contorl & Relay Panels' using PLCs and SCADA system.

Draw Electrical Circuit
The software lets you draw any type of complecated electrical power and control circuit/diagram. You draw horizontal and vertical lines and put electrical symbols upon the lines to complete your electrical (power or control) circuit. Cross over points are automatically converted into shorting-links or may be changed to jumpers or vise-a-versa. The software contains almost all the symboles in its library required to generate electrical power and control circuits. Label all the electrical symboles through a pop up text box - just enter the name/specification of the item and put it near the the symbol. Put ferrul numbering on each wire as per your convenience and requirement. Give color to all the lines as red (R), yellow (Y) and blue (B). Default line color is black i.e., neutral (N). Select line thickness to differenciate between power and control wiring. Rotate electrical symboles by 90 deg or back to best suit the placement upon the power lines. Delete any electrical symbol or power line with right mouse operation. So this software can generate elctrical power and control circuits in semi automatic mode.

Single Line Diagram
Single Line wiring diagram is generated automatically.

Bill Of Materials
What ever you add to your panel or electrical circuit, every thing is added to bill of material sheet automatically. If you delete an item it is removed from the sheet itself.

Estimation & Costing
You get a detailed estimation and costing detail in the word formate for easy printout and distribution. Change item cost, panel board painting and fabrication cost, bus bar cost, labour cost, margin profit as per your system and set up.

Printouts
Take printouts of the complete design along with detailed bill of materials, estimation & costing sheet, general layout, single line diagrame (auto-generation) and finally complete circuit diagram (semi-auto mode). When you have completed the design part and would like to know the cost of your panel, options are there to see the individual costs of busbars and panels

Electrical Amps - Volts - Ohms!

A circuit diagram is essential to find your way around the machine electrically, it is a blueprint of the electrical interconnections within the machines control circuits.

More electrical/electronic technical drawing and circuit diagram examples, with short explanations, are being compiled to feature on this page. The purpose of them is to give a pictorial referance as an electrical technical drawing with an explanation of what's going on within it. This helps in getting used to seeing different types of technical drawing (for those that aren't used to them).

For those that are more technically minded, there are some more advanced technical and schematic drawings and techniques being drawn up as well to compliment the more basic stuff. Perhaps they may even give you a new idea or two? Stayed tuned!

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Typical PLC wiring set-up with a 24V DC supply.

This little electrical circuit shows a typical wiring set-up for a DC supplied PLC, the S/S terminal is a sink or source connection.

The sink or source terminal allows for different types of input sensors to be connected. In this example, the proximity sensor connected to PLC input X7 is a 'PNP' type, it refers to the internal switching transistor type.

This type of sensor supplies 24V DC to the PLC input terminal on being energised. As such the sink/source must be connected to 0V or common to provide a circuit. Of course for the switches, such as the start and reset buttons it's not important whichever way they're connected, but for sensors, it is.

In this case the sensor is a PNP type, the proximity sensor would not work with the PLC sink/source terminal connected to the +24V DC and the supply side of the switches to the 0V DC. Although the buttons would work fine either way.

This is because the output of the PNP electrical sensor signal, when operated,sources (produces) a voltage. This is usually a similar level to the supply positive, maybe less a volt or so.

The difference between the ouptut voltage and the supply is know as the ceiling volt drop. This is known as source or high side switching and is so called as we are switching the higher or more positive supply line.

So to compliment the PNP sensor and also complete the circuit path, the PLC must therefore sink the electrical signal. Of course the complete opposite applies to sinkor low side switching. This is so call as you would be switching the lower or more negative supply line.

This basic description will always hold true, but there may be other conditions in more complicated circuits. So bear this in mind when looking at more complex electrical and electronic switching circuits.

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Tapping off existing signals for the PLC.

This is an example of how electrical signals can be tapped off from an existing control circuit. The operation signal from top terminal of a control relay (on the right) is fed off through a diode to prevent any back feeding of false signal to the machine control. This relays terminal is a positive 24V DC when the relay is energised and so supplies the PLC input with the same.

The diode is not essential but it is in place as a good practice measure. When a machine is being fault found, engineers introduce signal voltage at various points in the process of investigating a fault. The diode provides separation from the machine and from being joined to another PLC terminal on the machine that may cause a 'lock up' situation, or even damage.

220VAC 3 Phase to 110VAC Single Phase

Nowadays, most CNC machines are using 220VAC 3 phase power supply to power up the spindle motor and other electrical components such as coolant motor and inverter. Other electrical components like lamp and servo drive are using 110VAC power supply, then in this case you need to step down the 220VAC 3 phase to 110VAC single phase.

Diagram below is showing you the simple technique to convert or step down the power line 220VAC 3 phase to 110VAC single phase. In order to convert the 220VAC 3 phase power supply into 110VAC 1 phase, you need to use proper electrical components such as Earth Leakage Circuit Breaker (ELCB) and 2 poles Miniature Circuit Breaker (MCB). You are strongly recommended to use some fuses to protect any electrical components on your CNC machine.

CNC Wiring Diagram

The CNC wiring diagram shown in this page is created using Mechanical Desktop Version 6 and the wiring digram is showing you the very basic CNC wiring circuit diagram. Basically this CNC machine controlled by the CNC machine controller which consists of a CNC servo drive to control all the electrical parts such as axes servo motors, coolant motor, hydraulic motor, spindle motor, lubrication motor, inverter, working light, DC contactors and DC reversing contactor. The CNC controller panel is located in front of the CNC machine and not shown on this CNC circuit diagram.

The type of CNC servo drive shown on the diagram is 2 in 1 CNC servo drive which consists of servo drive and programming logic control section (PLC). The PLC section has some input and output (I/O). The electrical parts which will generate the signal such as limit switches, sensors, button, emergency switch and etc will be connected to the PLC input to be processed and the PLC will turn on some of the related PLC output. Those electrical parts that will receive the instruction from PLC such as motor, light, solenoid valve, contactors and etc will be connected to the PLC output. The output itself can be act as an input or signal to the PLC but the input never be act as an output.

Each axis servo motor and its encoder are connected directly to the CNC servo drive to ensure the CNC servo drive gain fully control on each servo motor in order to synchronize the movement of the mechanical parts especially the movement of machine tool on the raw material when machining the part. The coolant motor, hydraulic motor, lubrication motor and working light will be connected to DC contactors and each contactor will be connected to the servo drive PLC output.

The rotation of the spindle motor whether clock-wise (CW) or counter-clock-wise (CCW) is controlled by the DC reverse contactor when instructed by the servo drive. The encoder of the spindle motor is connected to inverter and servo drive to ensure to machine tool can do rigid tapping. In fact, you can connect the output spindle CW and the output spindle CCW on the servo drive directly to the inverter CW and CCW respectively to control the spindle rotation direction without using DC reversing contactor.

The limit switches are used to determine the homing position and the maximum travel distance of each axis. All the limit switches must be always in close position or normally close (N/C) as shown on the circuit diagram.

Electric Energy Through Magnets, Yes It Is Possible

As the cost of electrical power is growing daily, individuals are thinking to create use of solutions which are energy-efficient and may well lower their cost of electricity too. Individuals are badly hurt because of energy prices hike lately that is going on regularly. Electricity supply providers are charging high expenses for his or her services towards the customers because of the rise in fuel costs worldwide. Inside the last stage, the whole burden of the hike might ultimately have to be bear via the finish clients that are customers no matter whether in offices, industrial facilities or houses. In offices and industrial facilities, they compensate themselves by moving their elevated cost for their finish customer the public. Because of this cycle, the finish consumer is compelled to discover other alternative solutions.

Other alternative solutions include generation of electricity by means of solar panels, wind generators, fuel usage machines and also the new innovation of technology that's magnetic machines. Cell is much less well-known on small-scale given that it really is employed underneath the unique conditions. It takes huge space on best of your homes roof for installations its installation charges will also be high. The wind generator also requirements significant space inside your lawn or at roof best. Additionally, it calls for enormous power production and installation charges. The 3rd the first may be the fuel generator which makes use of gas, diesel or gas for electricity generation. This method is incredibly pricey and by no means achievable. Now generation of electricity using the magnets may be the greatest alternative. Yes you'll be able to produce cheap electricity by means of magnets. It is an innovation in magnetic technologies together with a brand new and least costly approach of electricity generation. This innovative mechanism of magnets produces low-priced electricity.

In magnetic generator, magnets are accountable to generate low-cost electricity. Magnets due to their special and diverse property of polarity move the turbines. Once it begins, it continues to maneuver turbine and manufacture of electricity under its thrust. Magnets have repulsive pressure which will aid along the way of electricity production. Magnets are arranged in a way that they'll supply in the ideal strategy to generate electricity. The magnetic machines have economical costs given that its parts are generally on the market even at nearby hardware shops. It is also atmosphere friendly. It doesn't generate any kinds of toxic fumes and seem that is why it doesn't lead in growing the environment and environmental noise. The electricity produced by way of magnets can price you pretty less quantity as in comparison holiday to a achievable alternative of electricity generation. By utilizing magnetic generator for electricity generation whether or not for residence, office or factory it can be effortless to cut lower your monthly electricity expenses.

Parts Of Electrical Control Panels

The Electric Control Panels, also called Power Distribution Boards, Service Panels and Panelboards, are basically designed to distribute electricity to all the electrical appliances of your home. These panels are installed in each and every home and building. They act as a distribution point, lightening up the houses.

Housing

Every Electrical Control Panel has a housing that supports its internal components. All the parts within the panel are insulated and therefore, no scope of short circuits is left in it. Control Panels are further protected with doors that have a caution mark with Authorized Personnel Only written upon them. No one except the electricians is allowed to open that door.

Main Disconnect

When the electricity comes into Electrical Control Panel, it is redirected to the main disconnect at the first place. The main disconnect acts as an on-off button, and if its lever is pushed off, the incoming power gets completely disconnected. The function of main disconnect becomes pivotal in case of any short circuit or overload, as by pushing it off you can save the entire Electric Distribution System.

Circuit Breakers

After the main disconnect, the power distributed into the different circuit breakers. Although breakers can be turned off manually, but in case of short circuit, they sense the overload and trip down automatically. In this manner, the circuit breakers help the circuit from getting overheated, which can otherwise cause fire.

Now that you know the basics of Electrical Control Panel, you need to consider a few things before purchasing one for any residential or commercial purposes. You need to check on the certain things and then only you can buy a reliable Electrical Control Panel. Following are some of the things to remember:

Safety standards

Quality of circuit breakers

Is it Weather proof?

Whether its controllers can withstand high temperature or not

Does it have voltmeter and integrated main switch fuse unit?


Enquire your Power Distribution Boards Manufacturer, Supplier and Exporter about these things and then only select the one that provides you with the Power Distribution Board you can bank upon.

The Use Of Electrical Appliances

Home appliances include all of those appliances that are used in home. It is a very broad term that encompasses everything from electric toothbrushes to washer/dryers. These appliances can be large or small. Major household electrical appliances are called white goods and include air conditioners, dishwashers, stoves, refrigerators, washing machines, dryers, etc.
Any home appliance that is purchased today should be energy efficient in order to save money. Federal regulations have to be listed on any appliance purchased, so you can see what you are buying and how energy efficient it is. This is particularly true with furnaces, refrigerators, freezers, water heaters, washing machines, dishwashers, air conditioners and lamps.
Everyone loves deals and discounts; everyone wants to show off something that they bought at a discounted price. There is lots of stuff that you can buy for less such as books, shoes, food and furniture. But some of the hottest selling items over internet are home appliances and electronics, such as Multiplex Island Display Freezers, Long Draw Draught Beer Dispensing Systems, Prep-Counters, and many others.

The need for home appliances is increasing day-by-day. It has become close to impossible to even think about not having any home appliance in your house. The home appliance companies have carved a niche in the market with its top notch products. This has ultimately resulted in the cut-throat competition between the products of different companies in the appliances industry.

In this 21st century all sorts of home appliances are like must for every household. Modern household depends highly on these household equipments. These appliances have got many such features and applications that can serve the purposes of not only household, but also institution or commercial places.
There are so many brands of electronics and consumer products that makes the task of finding the best product is very difficult. All the brands offer great products and bring innovations and new things which make them more useful. These latest inventions have changed the way we spend our time in living room, kitchen and laundry room. They are very famous consumer products. Most of the models of washing machines come with dryer combo with similar colors and aesthetics. One can also place them on top of each other.

Future Possibilities For Electricity

Immediately after the first electric appliance was created, these devices were refined and increased in complexity. It seems odd today, but some old electric appliances sometimes had cords covered with fabric that just weren't safe when compared with the devices you can find in your local department store today. The way you use electricity is also changing, even if the evolution goes too slowly for you to notice. Here are some interesting advances that will improve the way you use and pay for your electricity.

Many people want to put solar panels on their homes, but are intimidated by their cost and size. Thankfully, science marches on, and, according to EurekAlert, Boston College researchers have figured out how to make thinner solar cells that also produce large amounts of electricity. The challenge was how to harness the energy in "hot" electrons: those mobile electrons at a lower energy state that can sometimes be harmful for electronic devices. Before long, your home could be creating most of its own electricity after this development is put to more practical use.

When you think batteries, you likely think about those round metal bits that go into your remote control or the unseen power source in your mp3 player. This could all change, thanks to scientists at Stanford University. Science Daily reports about the possibility of turning paper into batteries. Once the surface of a piece of paper is coated with carbon nanotubes and silver nanowires, the paper is able to transmit energy quickly and store a lot of it. (The prefix "nano," from the Greek word for "dwarf," means that the tubes and wires are microscopic.) The scientists who developed the technology think it will improve the efficiency of the world's power grid because it allows energy producers to store the electricity they make for release at a better time. Imagine: your notebook could carry a bunch of electricity in addition to your good ideas.

A game-changing electric appliance is on the horizon for many households. Plug-in electric cars will be in your local dealership by 2012. Instead of pulling up to the gas pump every few days, you will simply plug your car into an outlet in your garage each night. (This means many of us will have to organize the things in our garages to make some room for our new cars!) While you'll save money by not purchasing gasoline, you will have to purchase the electricity going into your car's battery.

One of the many challenges scientists must overcome during the development of batteries for these cars is how to transmit the power to the electric motor fast enough. (We should all admit it: we love acceleration when we're behind the wheel.) Well, researchers working under Professor Ehud Gazit at Tel Aviv University have been able to create tiny peptide structures that, when examined under a microscope, look like a lush lawn. As Tree Hugger states, this material can be used as a supercapacitor. When incorporated into the new batteries under development, these peptides could zip the energy along quickly. (Interestingly, these materials also make it easier to clean solar panels.)

Plug-in electric cars will probably become much more popular when more homes are equipped with a smart meter. These advanced devices will allow you to consume more energy during off-peak hours, when your utility likely charges you less for each kilowatt/hour you use. (The price is lower because of good old supply and demand. Less electricity is used at night, so each unit is slightly cheaper.) Smart meters also expand your power monitoring options and can generate e-mailed reports that can break down your energy use by single appliances.

Perhaps most importantly, those smart meters will be tied together to create a smart power grid. Many of those blackouts and other interruptions you hear about in the news will be prevented when this grid is in place. It's all about communication; the meters in your home will tell power substations where more electricity needs to go and when. (In many places, the primary roadblock for adoption of these meters is their relatively high initial cost. When you're presented with the choice, remember: they may cost more to begin with, but they will save you money in the long run.)

Once American industry takes advantage of these and other scientific advances, we'll enjoy energy that is good for both the environment and our wallets. (If we're very lucky, we could be driving around an electric car powered by a notebook on the passenger seat!)

Useful Information About Electric Motor Repairs

Industrial work has great reliance on the usage of electrical motors. Businesses manufacturing food, drinks, paper, plastic, together with other materials we've got at present make use of these types of equipment. Various other enterprises such as publishing and automotive likewise use various types of electrical motors for their operations. Like any other machine, they are able to also cease working at some time. When that happens, it could possibly impact the overall production of a business. This is when electric motor repairs go into the picture.

Being a great businessperson, you should ensure that your business functions are running easily and successfully. A malfunctioning piece of equipment may mean a bad loss in the production as well as in your company revenue gradually. These kinds of situations need a good judgement on your part. It's true that you're going to get more coming from a new one. You must understand, even so, the fact that the expense plays a significant thought too. Brand-new motors are costly. With this thought, you simply must evaluate the expenses and benefits of your options-having electric motor repairs or purchasing a brand new model.

In the event you prefer repair, you can find many organisations delivering expert services such as electric motor repairs. Doing a search online enables you to pick from different firms. Put in mind that you need to not select the very first firm you see on screen or on the phone directory at once. You will need to contemplate a number of things before signing an agreement with one firm. The following tips can be useful when you are determining on a company to present services for the damaged electric device.

Hire a firm that could provide customized services for the certain repair needs of your motor. You must remember that the results of the repair depends upon the degree of the damages. A lesser amount of damage means better chances of getting your equipment back on productive working condition. Bearing this in mind, make an effort to employ a repair company that can provide the best results.

Additionally, you have to pick a firm that works 24/7. In addition, you should contemplate pickup and delivery of the equipment. If you find it a headache on your part to take the machine to the shop, opt for one that offers onsite service. Check also if they've got cranes and special lifts to fix heavier types of motors.

There is less to worry when you choose electric motor repairs with all these features. If you wish to go for an extra mile, you should employ other cost-effective decisions. You may minimize the need for such repairs if you have a regular maintenance program in place. This will help you guarantee that the engines are running at a maximum efficiency level. In this way, you can also reduce the chances of future costly repairs or worse, replacements.

Electric engines, particularly those used in big industries, cost much cash. That is why wise owners of electric motors in Australia do not immediately buy a new one to replace a damaged machine. Get those motors back in their perfect working condition by making use of quality repair companies.

Is Versatility Important In Dc Electric Motors?

DC electric motors are available in a wide variety of different sizes and configurations to suit different applications. Some models are designed to be suitable for a number of different powering actions, making them perfect for many different machines and applications.

The machines are used for such varied applications as lifting gates automatically, powering vehicles to run in harsh weather conditions and extreme temperatures and bi-directional winch powering. The most versatile machines are heavy-duty and rugged enough to work in any environment and delicate enough to control precise and complex movements.

The construction of these basic machines is relatively simple. In every model there is an axle which holds the armature, which consists of a set of electromagnets, and commutator. Each model also contains a magnetic field. It is this, combined with a direct current of electricity that produces torque or force. This simple principle, when configured correctly, produces a huge variety of different results.

It is important for these machines to be versatile so that a comprehensive variety of movements and actions are available from the one machine, working on one basic principle. All DC electric motors have their operational limitations, however. When selecting a particular model for a specific application it is important to choose one that is in the correct load torque range to ensure that the motor runs at its optimum pace and that no energy is wasted.

The best versatile DC motors are durable and energy efficient even when used in unusual application. Brushless models are preferable because there is less friction within the machine and they take longer to wear out. Brushless machines use a separate speed controller which provides pulses of electricity to control the spinning speed of the motor. This allows for greater precision and a longer working life.

DC electric motors can be used in heavy duty industrial applications as well as in miniscule domestic applications, including the appliances you use every day and childrens' toys. Although there are many different models created for powering specific machines, each machine works on the same principle, and many are compatible for different applications.

The most versatile machines deliver a regular, reliable and constant speed and movement. These DC motors can be adjusted to provide the exact speed needed in pretty much any given application, so that any machine can be reliably powered. Some models are also reversible, meaning that it is possible for the machine to change direction while it is moving.

Electric Motor Repairs - A Necessity For Every Single Company

Machines have made people's lives easier ever since the Industrial Age. Today, many industries count on electric motors in Australia. Just about every company in the production industry uses different machinery to make procedures easier. Machines happen to be effective in speeding up the manufacturing and assembly processes and making them uniform. They, however, have confines as well. Engines can stop working eventually because of heavy load, everyday use, or outside factors. This stalls production indefinitely and impacts your company negatively. Situations like these demand professional electric motor repairs.

New Machine or Professional Repair Services?

Business owners in the production industry realize that time is money. Clients see businesses with the faster production time as more efficient. A smooth-running business operation will deliver products on time, bringing in more profit as a result. Broken machinery can put your company in jeopardy if you don't act on it promptly.

You need to analyse whether you should replace your broken equipment with brand new machines. Take an engine's overall physical condition and age under consideration when coming up with this decision. Cost is a major deciding factor likewise. Determine if purchasing new equipment may well be more economical than going for electric motor repairs.

Finding Professional Repair Services

Most large and multinational companies come with an in-house technician to deal with broken gear. Smaller and medium-scale industries may not have similar resources. There are plenty of businesses that concentrate on repairing electric motors in Australia. Evaluate each of them carefully before stepping into a legal contract with your final selection. Your company's equipment - and therefore, your company - will be in their hands. You should choose expert technicians to handle your gear.

Hire a company that has experience in handling the kind of engine your machine uses. Alternating Current (AC) and Direct Current (DC) motors work differently, thus requiring different knowledge. You may also wish to go with a firm that are experts in your distinct equipment. Repairs for an air-con system are not like repairs for a turbine or perhaps a conveyor belt. Check out their portfolio of clients and demand to view training certification. Find out if they offer customized repair services in addition. Bear in mind the motor repair outcome will depend on the extent of your respective gears' damage. Customized services could bring better results.

Some professional repair services operate all round the day and night. These firms are ideal for businesses requiring emergency repairs in the the night time. Find out if you need to take your equipment to their own shop, whether they will send a vehicle to get your gear, or if perhaps they will conduct the essential repairs onsite. Guarantee that they have sufficient equipment to handle your machines well.

You could browse online for professional repair service providers. Make sure you read reviews from credible sources just before getting hold of a company. You can also ask your friends and colleagues for referrals. Compare prices likewise. Make an effort to negotiate with assorted firms to get the best value for their specific services.

Company owners have to take action when their equipment breaks down. Hiring firms that offer electric motor repairs in the onset of trouble helps keep your production schedule on track.

Industrial Electrical Supplies

Several branches of technology and engineering are available for industrial application. In automation, industrial architecture, industrial design, industrial process, industrial arts and industrial applicability, there will be a need for products to support continuing development and manufacturing of products and services.

Products of the industry may be identified among chemical industry, petroleum industry, automotive industry, meatpacking industry, hospitality industry, food industry, fish industry, software industry, paper industry, entertainment industry, semiconductor industry, cultural industry, poverty industry.

Primary sectors of the industry are agriculture, mining, and raw material extraction. The secondary sector of the industry is manufacturing. The tertiary sector of the industry is in service production. Sometimes, there is a quaternary sector of the industry pertaining to intellectual services like research and development.

All sectors of the industry use electrical power in order to operate office equipment and industrial machinery. Electricity also provides sufficient energy for commercial lighting, cooking, and industrial processes. Because of the vast demand for electricity across all industries, it is viewed as a public utility infrastructure.

The four processes of the electrical power industry are power station, electric power transmission, electricity distribution and electricity retailing. These are geared towards electricity generation. The entire electrical power industry is heavily regulated because it is a natural monopoly wherein basically every member of the population demands it.

Industrial electrical supplies refer to all products and accessories that require electricity to operate and are used across all industries. Majorly, industrial electrical products include all fittings, wire, circuit breakers, safety switches, fuses, contactors and starters, lamps, and more. Other offerings include motors, lighting, material handling, fasteners, plumbing products, tools, and safety supplies. Companies marketing such supplies generally take out revenue on a business to business rather than a business to consumer relationship.

Companies providing industrial electrical supplies are built to provide efficient solutions for industries especially responding to the demand of electric motors. With the extremely flexible form of energy, electricity has been adapted to huge and growing number of uses. One best example industrial electricity use is in the telecommunications industry which has enabled communications around the globe in seconds.