Selecting components for crowbar circuit.

Thread Starter


Joined Aug 20, 2019
Dear All,

I need to make a protection circuit from over voltages (Protect from more than 5V, Expecting inputs are 6V to 30V and need to protect from above 5V voltages) and current(Protect from more than 5A)

Could you please suggest components for following circuit ? Please suggest me ZD1, Q1, C1, C2, R1 values for above specifications.

Are there any IC with above spec which included crowbar circuit from Analog devices or any other product.

1) ZD1 triggers Q1 when V_zd1 + Vgate_Q1_trigger equal the desired trigger voltage - here about 6V.
So Vzd1 needs to be about V_trigger - Vgate_Q1_trigger Can you suggest me a component ?

2) Q1 needs to be an SCR rated at usefully above Vin_max (here 30V) and able to smile at I_over _load (here 5A) Suggest me a component.

3) C1, C2, R1 ?