Silicon controlled rectifier called SCR was first introduced in 1957 as a power semiconductor device the same way other semiconductor devices used as switches or rectifier electronic circuits called switch-mode power supplies. This device is also called a power device or some time it will be used in the integrated circuit, called power ICs.
Most of these semiconductor devices are listed below and it along with device and present advantages is maximum ratings.
- Diode - Voltage or current rating - 5000 V/ 5000 A
- Full form of SCR(silicon controlled rectifier) - Voltage or current rating - 7000 V/ 5000 A
- LASCR called (light-activated SCR) - Voltage or current rating - 6000 V/ 3000 A
- ASCR/RCT called (asymmetrical SCR / reverse conducting thyristor) -Voltage or current rating - 2500 V/ 400 A
- Full form of GTO called (gate turn off thyristor) - Voltage or current rating - 5000 V/ 3000 A
- Full form of SITH called (static induction thyristor) - Voltage or current rating - 2500 V/ 500 A
- Full form of MCT called (Mos controlled thyristor) - Voltage or current rating - 1200 V/ 40 A
- Full form of BJT called (bipolar junction transistor) -Voltage or current rating - 1400 V/ 400 A
- SIT called (static induction transistor)) - Voltage or current rating - 1200 V/ 300 A
- Full form of IGBT called (insulated gate bipolar transistor) - Voltage or current rating - 1200 V/ 500 A
Based on,
- Turn on and turn off characteristic
- Gate signal requirement
- Degree of controllability
The power semiconductor devices can be classified as under the following category
1. Diode: This is uncontrolled rectifying devices. Their on and off-state are controlled by a power supply.
2. Thyristor: These have controlled turn on by a gate signal. after thyristor is on they remain latched in on state due to internal regenerative action and gate loses control. These can be turn off by the power circuit.
3. Controllable switches: These devices are turned on and turn off by the application of control signals. The devices which behave as controllable switches areas like BJT, MOSFET, GTO, SITH, SIT, and MCT.
So the device like GTO, BJT, SIT, SITH, MCT, SCR, IGBT is unidirectional current devices, whereas RCT and Triac posses bi-directional current capability.