[Amps] SCR to adjust 240v to 200v

[Jim Durham]

Thank you, Boye (OZ7C) and the others that replied.  I think I did not 
explain my project clearly.

First of all, yes, I know about buck transformers.  I am using a Variac, 
which does the same thing and also allows me to adjust the input AC 
voltage. The Henry 2K has the filament voltage supplied from a winding 
on the plate transformer, so, with the Variac, I can adjust the input AC 
voltage to give about 9.8 volts for the filaments, which is ideal and 
produces 3000 volts for the plates.

A large buck transformer or Variac requires an external box, which is 
what I am using now. They won't fit in the amplifier without seriously 
hacking up the cabinet.  I don't want to do that.

So, I was just asking if anyone on Amps had tried using an SCR to 
control a large choke-input power supply ?   That sounds attractive and 
would fit in the cabinet,  but also might damage the power supply choke 
by applying non-sinusoidal power (the 2K-2 has a choke input power 
supply).  That was my question.

Thanks to all,  I should have explained more clearly what I was asking.

73 de Jim, W2XO


On 08/13/2016 12:52 AM, Boye Christensen wrote:
> Hi Jim
> Do no know that amplifier.
> Can't recoment it.
> Fist this will be ok to reduce the filament power.
>
> Depending on what type of recifier type HV is?
> If is a standard recifier with capitors the peak voltage will still be 
> high.
> If it is a choke type  like Henry 8K this need a sinus voltage.
>
> The best you can do is to find a transformer   Pri/sek   200/40 Vac 15 
> Amp and insert it in
> phase the secundary vindings with the mains voltage to reduce voltage
>
> 73 Boye. OZ7C