Sjöström Audio DIY forum

Projects => Power supplies => Topic started by: alexanderbax on June 15, 2017, 01:09:59 PM

Title: SSR03 rectifier section not working
Post by: alexanderbax on June 15, 2017, 01:09:59 PM
Hi Pers,

I have built a power supply with 4 x SSR01 and 2 x SSR03 in it.  Im using a customised centre-tapped toroidal.  All 4 SSR01s are working perfectly and the fist SSR03 is as well.  However, on the other SSR03, which I am powering with 23VAC secondaries is acting quite strange.  The negative side is outputting a nice -22VDC which is exactly what I need.  However, the positive side is not outputting anything. 

I went back and checked X1 to X3 and X4 to X3, and I am getting 23VAC on both sides.  So then I checked the rectifier section, and I get -32VDC at the unstabalised output but +0VDC.  Then I checked the voltages of the diodes and only D3 appears to be passing the correct 32vdc.  D4 shows as zero, as does D1, but D2 has a voltage of 5vdc!!!  I changed out the diodes for brand new ones in case they were faulty and I have exactly the same readings!  Its seems odd because I get 23VAC at both AC1 and AC2 but something seems to be going wrong in the rectifier section..... yet surely that is the easiest thing for me to get right???
Title: Re: SSR03 rectifier section not working
Post by: peranders on June 15, 2017, 04:05:29 PM
Start with one side at the time.
One winding to X1:1
Center tap to X1:2
Measure the voltage at R9.

Negative side:
One winding to X1:4
Center tap to X1:2 (or 3)
Measure the voltage at R10.

Measure between center tap or GND and the resistors.

Does the transformer have two separate primary windings? Four wires?

You can also use the X2 terminal for measuring the raw voltage.
Title: Re: SSR03 rectifier section not working
Post by: alexanderbax on June 15, 2017, 10:04:19 PM
Ok

X1:1 and X1:3 voltage @R9 = 0vdc (I'm getting 23vac from the winding)

Then removed the above and connected X1:4 and X1:3 voltage @ R10 = -30.6vdc

Yes the transformer has two separate secondary winding, but the manufacturer connected the middle two for me to create a centre tap wire to connect. Like I said the winding used on my 10v SSR03 work fine so I don't think it's an issue with connecting the transformer.
Title: Re: SSR03 rectifier section not working
Post by: peranders on June 16, 2017, 06:15:45 AM
Have you checked D1, D2, R1, R2? The diodes are mounted in the right direction?
Title: Re: SSR03 rectifier section not working
Post by: alexanderbax on June 16, 2017, 08:58:00 AM
Diodes definitely are. Good point on the resistors, I haven't checked if they were faulty. I'll let you know!