Sjöström Audio DIY forum

Projects => Power supplies => Topic started by: Sjoerd Smits on January 27, 2013, 11:48:48 AM

Title: Large voltage drop SPS01
Post by: Sjoerd Smits on January 27, 2013, 11:48:48 AM
Hi PA,

I get a really large voltage drop when I connect the amps to the SPS01 power supply. NEG-Ground = -17VDC and POS-GROUND= 22VDC

Unloaded the voltages are 33VCD.

I have a toroid from Amplimo whitch provides 2 x 25VAC at 10 Amps.

I purchased the rectifiers directly from you. You provided me with 8x MOSPEC U30D20 rectifiers. The datasheet of these rectifiers state that the operating voltage should be between 50 and 200V.

So I see 2 strange things:
1: It takes upto 3 minutes for the SPS01 to go from 0 to 33VDC.
2: When load is applied, the voltages drop dramaticly to 17 and 22 VDC.

Question: What could be the problem?

Kind regards,
Sjoerd Smits
Title: Re: Large voltage drop SPS01
Post by: peranders on January 27, 2013, 02:57:02 PM
Are X3 and X4 shorted or do you have a resistor there?
Title: Re: Large voltage drop SPS01
Post by: Sjoerd Smits on January 27, 2013, 03:10:38 PM
Hi PA,

Found the problem.... It was X3 and X4... I had nothing there.... so that was the problem!

Thanks!

Regards,
Sjoerd
Title: Re: Large voltage drop SPS01
Post by: peranders on February 03, 2013, 06:37:59 PM
You mean instead of 2 x 24 VAC you had only 1 x 24 VDC?

Good to hear it's working.