View Full Version : Power One 5V/3A supply help!

2007-05-30, 13:28
Hi all,

I salvaged the above PS, new (apparently) and in box recently. Its labelled HB5-3-OVP-A. When I connected it up as per the instructions for 240VAC (jumper 2+3, apply AC at 1 and 4) the fuse at my distribution board tripped. Now I know these things can draw extra current on startup, but my trip switches are slow blow ones because I run various pieces of industrial machinery from them (3Kw motors). So I reckoned there must have been a problem with the Tx. On putting a DMM across the 1 and 4 terminals I get 0.2 Ohm resistance.

Now here is the unfortunate part, I then hit the terminals and shorted out the bloody Tx, frying some of the wires inside the primary.

Now for your help: Would anyone know what voltages the secondary of the Tx puts out - there are 3 terminals at the output of the Tx, with 2 black wires and 1 white one. Could someone stick a DMM on these and tell me what the AC volts into the regulation circuit is?

Help would be most appreciated!!!


Builder Brad
2007-05-30, 14:24
Hi Fran

I did exactly the same thing with my Power One 5v PS.

The transformer 2ndary voltages are 9-0-9 v, connected in series. I used a 50VA frame transformer from Maplins and connected the white wire marked AT to both 0v termonals of the transformer and the 2 black wires marked A to the 2 9v terminals. This works perfectly for me and the Maplins 50VA transformer is a bit meatier that the one orginally fitted in the Power One PS.

good luck + make sure you double check in case your unit differs from mine.


2007-05-30, 14:33
many thanks for that, its stock no. N92AZ or N12CF. If they don't have it RS probably will.

EDIT: they do, RS has it its # 805-120. I need to get another Tx as well so I reckon I'll deal with RS for now.

Again, many thanks.


2007-06-09, 17:51
Just to update the thread:

I got the Tx from RS. With some slight mods to the case, it will actually fit in and replace the original Tx although it does poke out the side just a tad.

I got it built, mounted it in a old PC PSU case - this is a very handy way of mounting it as it has loads of vent holes, a fan if you need one, an IEC socket already in place and is just the right size for the job.

When I first powered it up I had 5.5V out, but I adjusted that down to give me 5.01V at the end of my lead. I would have liked to have measured it "on load" but haven't got that far yet. Haven;t listened critically for SQ differences yet. Unit gets warm but not hot so far.

More later....


2007-07-12, 16:37
Just wanted to update.

I'm using the SB3 into a DAC (zhaolu 2.5C) and to be perfectly honest I can't hear any improvement with the linear supply. Can't comment on what you get using the analog out on the SB, but to my ears I can't hear any benefit if you're using a DAC.