The difference of SCR (silicon controlled rectifier) and DIAC (diode alternating current) are given below,
| SCR | DIAC |
|---|---|
| The SCR stands for silicon controlled rectifier. | The DIAC stands for diode alternating current. |
| The SCR is a four layers PNPN device with three terminals namely anode, cathode and gate. | The DIAC basically a two terminal device. It is a parallel inverse combination of semiconductor layers that permits triggering in either direction. |
| It is a high power device. | It is low power device.. |
| It is a three terminal device. | It is a two terminal device. |
| The break over voltage can be controlled by adjusting the gate current. | The break over voltage cannot be controlled. |
| The symbol is
|
The symbol is
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| The breakdown voltage is ± 26 V. The maximum anode current is 25 mA. | The forward break over voltage is 40 V. The maximum anode current is 100 A. |
| It is used in applications like dimmer, control light, fan etc | It is used as a triggering device for the TRIAC. |
