RA-1 Power Questions

[jiggler]

I was wondering if anyone has the schematic or photograph of the power supply for the RA-1, including the LED and power switch. There is already a thread here concerning the power supply but the schematic and suggested changes to it seem wrong, i.e., the LED is only on one side of the virtual ground.

My second question is whether using the 2x 9v power supply shown in Chu Moy's original article for the cmoy would be a good alternative for the RA-1 and, if so, whether it would require any tweaks to the RA-1 design.

Thanks in advance for your help!

 

[Budgie]

Have you looked here?-

http://www.geocities.com/rubin_jpk/rubin/page_4.html

 

[jiggler]

Yeah, I looked at that. I am not sure where a switch and LED would properly go into that power supply though. That is why I asked the question.

 

[Budgie]

The power switch will need to interupt both the + and - supply lines so you will need a double pole switch.
I would put the LED across both batteries= from +9 to -9 so that the draw is from both batteries. Calculate the series resistor as if it was an 18 vdc supply.
I hope that helps.

 

[jiggler]

YES! That is exactly what I needed. Thanks.

 

[hottyson]

[size=xx-small]This is basically the amp I will be building with a few value changes. (Big Solen caps)[/size]
Quote:

Originally Posted by Budgie The power switch will need to interupt both the + and - supply lines so you will need a double pole switch. I would put the LED across both batteries= from +9 to -9 so that the draw is from both batteries. Calculate the series resistor as if it was an 18 vdc supply.

There will then be an added circuit for the LED. I am assuming that this will not effect the sound quality?

If not effecting the sound quality, any recommendations on a low current, easy to mount (Are they all easy to mount?) blue LED, and appropriate resitor?
Mouser LED's or Digikey LED's or ???

I am about to order all the parts. Thanks for the help.