Anyone have schematics for this psu module?

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pucho812

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See photo. Pretty simple design but the toroidal has no markings on it.

As there are no markings on the transformer, want to confirm mains voltage. Right now it runs when seeing u.s. mains but output is low, should be 24vdc I see 15vdc at output.

On the bottom is says “serie A 133”
Top says “type 4-17068”
 

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'Serie' suggests its of French origin ,could of course be Canadian too , or Belgian ,
Maybe Abbey knows something about the maker.
 
I don't know if this is helpful but that format looks very like the racked comms supply made by many of the large telecom providers. Of course they are now mostly SMPS, though it sounds like this is a linear one. Also the telecom supplies usually run at 48V. I would suggest opening it up and start probing voltages (if this is within your skill/safety level set as there obviously are mains voltages in there), looking at the voltage ratings for reservoir capacitors and maybe for some manufacturer labels (like perhaps Honeywell if it is indeed French). Similarly, if there is some voltage regulation (which one would hope there is) you can look at the parts used for guidance and the resistors will tell you what the target output voltage is if it's one of the 3 pin adjustable regulators (something ending 317, 337 or 338 usually, or 78xx/79xx where xx is the output voltage). Hope this helps.
 
I don't know if this is helpful but that format looks very like the racked comms supply made by many of the large telecom providers. Of course they are now mostly SMPS, though it sounds like this is a linear one. Also the telecom supplies usually run at 48V. I would suggest opening it up and start probing voltages (if this is within your skill/safety level set as there obviously are mains voltages in there), looking at the voltage ratings for reservoir capacitors and maybe for some manufacturer labels (like perhaps Honeywell if it is indeed French). Similarly, if there is some voltage regulation (which one would hope there is) you can look at the parts used for guidance and the resistors will tell you what the target output voltage is if it's one of the 3 pin adjustable regulators (something ending 317, 337 or 338 usually, or 78xx/79xx where xx is the output voltage). Hope this helps.
Well within what I do on the daily. Runs a fixed regulator(7824)
 
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Well it receives main voltage and outputs 24vdc if working correctly. I say that as it was supposed to be powering modules which ran off 24vdc.
The circuit is so basic an easy trace can be done
 
So what is the problem that still needs solving? If a 7824 is well within your expertise then we can assume it's working properly and the reg isn't getting enough voltage (you can check what's going in). It appears to need a European voltage of circa 230V. The then 30V (plus) output gives the regulator at least 6V to play with, which is pretty generous - certainly enough to deal with low mains and a weedy transformer. This sounds like an absolutely bog standard supply and is nothing you couldn't build yourself. If there is anything else that needs explaining then it will probably help to include a photo of the innards. You can probably find the circuit being used on the 78xx datasheet and, if not, I seem to remember the LM117/317 datasheet has a ton of circuits in the Application section of its datasheet. I suspect you're looking for one of the most straightforward applications there.
 
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So what is the problem that still needs solving? If a 7824 is well within your expertise then we can assume it's working properly and the reg isn't getting enough voltage (you can check what's going in). It appears to need a European voltage of circa 230V. The then 30V (plus) output gives the regulator at least 6V to play with, which is pretty generous - certainly enough to deal with low mains and a weedy transformer. This sounds like an absolutely bog standard supply and is nothing you couldn't build yourself. If there is anything else that needs explaining then it will probably help to include a photo of the innards. You can probably find the circuit being used on the 78xx datasheet and, if not, I seem to remember the LM117/317 datasheet has a ton of circuits in the Application section of its datasheet. I suspect you're looking for one of the most straightforward applications there.
The only issue here is if I need a step up transformer or not as I am in the u.s. hence wanting a schematic to confirm mains voltages at the primary as the toroidal in the unit has no markings
 
The first thing I would look at is whether that toroid has a dual primary. Then you won't need a step-up. After checking what the voltage into the 7824 is! That's the pin on the right as the body faces you.
 
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I wouldn't have expected a voltage switch but, just to check, there are only four wires coming out of the supply? Yes?

Why don't you just check the RMS voltage coming out of the transformer and the DC voltage after the rectifier? That should tell you all you need to know as well as whether it's working or not. If you are going to buy a step up then why not just buy a similar sized transformer outputting the required RMS voltage on US mains. That would save you some packaging problems as well as some money.
 
I wouldn't have expected a voltage switch but, just to check, there are only four wires coming out of the supply? Yes?

Why don't you just check the RMS voltage coming out of the transformer and the DC voltage after the rectifier? That should tell you all you need to know as well as whether it's working or not. If you are going to buy a step up then why not just buy a similar sized transformer outputting the required RMS voltage on US mains. That would save you some packaging problems as well as some money.
The supply is single ended so only 2 wires coming out.
The power trafo has 2 wires at primary and 2 wires at secondary
 
Do you not have a variac? Or are you already running it on 115v? If so, measure the secondary voltage. If it is low, then there is your answer.
Its not exactly rocket science.
 
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