SCR based voltage regulator

[niranjay_r]

Hi,
a friend of mine wants to build an SCR (silicon controlled rectifier) based AC/DC voltage regulator. Any ideas where he can find a circuit?

 

[Nigel Goodwin]

Hi,
a friend of mine wants to build an SCR (silicon controlled rectifier) based AC/DC voltage regulator. Any ideas where he can find a circuit?

You can do one for AC, using phase shift control, usually using a bridge rectifer so you can control both positive and negative peaks. DC is more of a problem, as you need some way of turning the SCR off - on AC it turns off automatically as the voltage drops to zero.

It doesn't seem a very good choice for a voltage regulator, what is he wanting to control?.

 

[stevez]

Could you control the AC input to the rectifier as a way to control the output of the rectifier/rectifier assembly?

 

[Styx]

SCR will be fine with firing angle control. That way by changing the firing angle of the tyristors you can change the average DC link value (you will need a decent cap tho).

And since you are controlling on the AC side it is natually commutated so the Tyristor automatically turn off (as long as you remove the gating pulse)