The insulated-gate bipolar transistor or IGBT is a three-terminal power semiconductor device primarily used as an electronic switch and in newer devices is noted for combining high efficiency and fast switching. It switches electric power in many modern appliances: Variable-Frequency Drives (VFDs), electric cars, trains, variable speed refrigerators, air-conditioners.
How a clamp meter works:
In electrical and electronic engineering, a current clamp or current probe is an electrical device having two jaws which open to allow clamping around an electrical conductor. This allows properties of the electric current in the conductor to be measured, without having to make physical contact with it, or to disconnect it for insertion through the probe. Current clamps are usually used to read the magnitude of asinusoidal current (as invariably used in alternating current (AC) power distribution systems), but in conjunction with more advanced instrumentation the phase and waveform are available. Very high alternating currents (1000 A and more) are easily read with an appropriate meter; direct currents, and very low AC currents (milliamperes) are more difficult to measure.
A CURRENT TRANSFORMER (CT) is used for measurement of alternating electric currents. Current transformers, together with voltage transformers (VT) (potential transformers (PT)), are known as instrument transformers. When current in a circuit is too high to directly apply to measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to measuring and recording instruments. A current transformer also isolates the measuring instruments from what may be very high voltage in the monitored circuit. Current transformers are commonly used in metering and protective relays in the electrical power industry.
In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal.
A diode is an electronic device which allows current to pass through in
one direction but not in the other. It is commonly used in another device call a bridge rectifier which is used to convert alternating current into direct current.
A pressure transmitter is a pressure sensor, typically for gases or liquids. This pressure sensing device has current output. It can also be defined as an analogue device that produces a charge in voltage or current when the internal pressure changes state.
A thyristor is a four-layer semiconductor that is often used for handling large amounts of power. While a thyristor can be turned on or off, it can also regulate power using something called phase angle control. This allows the amount of power output to be controlled by adjusting the angle of the current input. An example of this is the a dimmer switch for a light.
