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I bought a Zerozone regulated PSU with 24v dc and 100 va for my little fx audio amp, which needs 24v/ 4A. I was happy with the sound for 2 month, but yesterday the fuse has blown and smoke came out the Psu. I opened the case and saw the transformer was only 115volts,
But the case outside is marked with 230v, what I need in Germany and have ordered.
The chinese seller explained me now that the transformer is made of 2 sets with 115v
Connected in series and the psu is Ok. Is this possible and how could I test it with a meter.
The seller shows now the same PSU on his site, but is pictured with a230v transformer.
Thank you for your information, maybe Im wrong.
Follow Ups:
It's a 28v 100VA transformer. 100VA/28V= 3.57 amps so maybe that's where the seller is coming from?? My guess is that you never or almost never drew 4 amps and it did work for two month?? This I believe shouldn't be the reason it failed?? Maybe the output transistor overheated and shorted??
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/07/19
This is like the one Duster showed and it come in 24v with giant heat sinks and he rates this, with giant heat sinks and all at only 3.3A @24v. WTF? So the one I put up as 8A, calculated down to 5A may or may not be correct but it sure seems incorrect just from a heat sink point of view. Maybe some electronics person can weigh in on this. The 8a-5a PS had what looks like the output device on a heat sink inside the unit so it's hard to tell how big it is but it sure looks like there wouldn't be much air flow. Something is amiss.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Each heat sink has a single component affixed to it.
![Optimus 100 Watt High Power Stereo Amplifier 12-1971 [untested]](https://i.ebayimg.com/images/g/13EAAOSwm-pct2IJ/s-l640.jpg)
Optimus 100 Watt Amp. Bet is sounds great too.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/08/19
Seems like you are correct that it's overkill but the other ones seem like underkill.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
This is the ticket. Saw nothing else like this. 8A for this money.
EDIT: He states the tranny is 120VA so, 120/24= 5 Amps, not 8 at your voltage. You got to watch these folks. Still looks good IMO.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/07/19
Nice supply. In the meantime, waiting for the parts to change on my deluxe supply, I thought why not try a simple solution. Bought for 11,5€ a supply with correct 24v/5A and made my
K-I-S supply. It is dead quiet and my little tpa3250 amp not sounded better with 130$ Zeroo.
Kind regards
Cool. Glad you're back in action.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/11/19
I have my eye on a Zerozone but now I'm losing sleep. Was there any offer to send you another one or any comment about reliability in general from the seller? Should have lasted a lot longer than two months. Good luck with your next PS. Ti Kan has no recommendation other than to build or have one built assumedly to his specs.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Thank you for your answers. The seller I bought the zerozone told me, the powersupply is not suitable to my amp and I should have asked him bevor, which amp I use. The amp is to drive with 24v /4A, the power supply, he sold me is 24V, 100W(4,2a). So I cannot recommend the seller.
Did you ask for an explanation why this seemingly adequate PS was unsuitable? I'm curious what the answer would be. The 2SC5200 are rated at 15A. Considering how cheap many manufacturers are it's a bit odd he is using a 15a device instead of a like 4-6amp device to save money. Maybe a good idea to get a PS rated above 125va?? Hard to find at the price point of the one that blew. Be fun to know why.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
I'm pleased with a Zerozone 100VA linear power supply upgrade for a 3A rated application, since I always choose a power supply upgrade that's rated substantially above the power rating of a stock power supply.
See link:
Now take a look at the heat sinks on that sucker. All the other ones I see have what appear to me to be very small heat sinks for 100-120 watts. That's quite a lot of heat. I'm not sure what's going on here.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Perhaps the heat sinks are a bit over the top for the application, since there is only one parts component affixed to each heat sink, but maybe that's especially beneficial for the design.
The enclosure is a 'one size fits all' enclosure for DIY projects.
It looks as though the PCB discoloration may be caused by smoke emissions from within the failed rectifier, and possibly not carbonized the FR4 itself, which may bode well for fixing the circuit.
You might try just replacing the rectifier diodes and see what happens. Maybe try some parts with higher pulse current capacity...
That is a massive input filter cap and if the correct balance of components was not utilized, inrush current may be exceeding the rectifiers pulse current handling capacity.
If it is carbonized board I'd definitely want to carve out the compromised FR4 before fixing and re-using it since the the more carbonized it has become the leakier it will be. Not good for fire prevention when enough energy is present to heat the carbon path to ignition temps.
Backside
Which parts on D2 could that be. I would like to change the pieces just fo fun.
The D1 to D4 parts (black rectangles with metal tabs) are the rectifier diodes (MUR1560) and the C1 to C4 (orange) are capacitors (not sure of value).
The MUR1560's metal tab is live and needs to be isolated from the chassis. Part of that isolation is the isolation sheet between the MUR1560 and the chassis which acts as a heat sink. The bolt that attaches the MUR1560 to the chassis must also be isolated from the tab with a plastic shoulder washer. A possible issue is that the isolation has failed and the tab is grounded electrically to the chassis creating a short, or the capacitor has failed and shorted across the diode.
^^ What he said.I'd be suspicious of the insulation between the screws holding the diodes against the chassis for heat sinking and the chassis. Not shown in your photos.
Edits: 12/05/19
It looks like the four diodes make up a rectifier bridge: "D2" adds verisimilitude to my assumption. The part number should be on it but the photo is not clear enough to determine what it is.
I'm reading that Teradac is well made but very expensive for what you need. There is a guy named Ti Kan that designs DIY units that is well respected on another forum. You might want to ask him. I was thinking about one of these units and now am thinking twice. Not the worst thing that can go wrong but a pain none the less. Good luck. EDIT: I've emailed Ti Kan to see if he has an opinion what brand to buy.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/05/19
Hello CG,
You are right, there is something burned. I dont know which parts they are, but I would try to change this 2 parts with new one. Could you tell me what it is? Thank you in advance.
Without a circuit diagram or the actual unit, I would have no clue.
Sorry about that
Can someone give me a recommendation for a better powersupply as this awful zerozone,which is now without function. The amp is a fx-audio 502s pro, which I use with a fx audio tube pre 03. The power amp came originally with a 24v 4A plug.
That is common labeling and specification for a transformer.
The primary is a set of windings, each nominally expecting 115 VAC. Put them in parallel for 115 VAC use. Put them in series for 230 VAC use.
Same idea for the secondary windings. Two in parallel provide up to 100 VA at 28 VAC, two in series provide up to 100 VA at 56 VAC. Or, use them separately for 28 VAC each up to 50 VA. Or, even, 56 VAC with a center tap.
Certainly, the transformer could've gone on to the afterlife. Of, another part could've died. But, the transformer primary spec is ok.
It's odd to me that some would be labeled with just one voltage and others clearly labeled with two. Looks like I got this incorrect but it makes no sense to me for there not to be a standard of labeling. Would have been nice if the voltage was the problem but with twice the voltage you would have thought that maybe it would have went bad immediately?
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/05/19
Transformer looks OK for the application. I have one of those transformers feeding a Synergistic Research FEQ, in a diy power supply.
A friend with a test meter could tell you what is wrong very quickly. Since it lasted two months, my hunch says it is not the transformer.
Best of luck...
My money is on it being the incorrect transformer or at the very least a mislabeled transformer. If you go on ebay other transformers are labeled correctly, like 2 x 110 or 115. An example below. Dollars to donuts you measure an incorrect AC voltage. If incorrect I'll pay up next time I'm in your neighborhood. EDIT: I retract my statement about the tranny being incorectly labeled. I must be getting old. It's says 0-115 twice and has the multiple colored wires. My bad.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/04/19 12/05/19
A better photo would be a big help. The well lighted photo needs to show the EIC connector and the wiring going to the primary (red, black, gray, orange wires) of the PT. It would also help to clip off all the cable ties associated with these wires. Is there any burned component? You said it smoked.
Thank you, Palustris. Here new photos.
What's the black ooze above the cap labeled D2?
The printed circuit board trace mask there looks discolored, as if it was overheated - too much current.
First thing I'd check is whether one or more of the rectifier diodes is shorted. Also, check the filter cap.
It could be bad parts. Or, perhaps you had a voltage surge on the AC mains input. Or, a design bug.
Or a cold solder point that created resistance which = heat, It is right on the trace.
It sucks to get old. It really sucks to get old and bitter.
Edits: 12/05/19
Good eye. I had to increase magnification to 200% to see it, but you're right. It's burnt.
Psu photo
OK, that's not what I was expecting to see. I was expecting to see the red and gray in series and the black and orange in connected to the EIC. Instead we have the red and gray connected to the EIC and we can't see the termination of the black and orange. I believe that if the black and orange are connected together the two transformer primaries are in series, but I wouldn't accept that as fact without checking it with my DVM first. Needs further study...
I agree the wiring based on the transformer label makes no sense. The primary connection (series or primary ) seems to be established in the transformer connection board. The wires running to the power switch should be switching the hot side of IEC though the connection board.
The black and orange are connected at the power switch. So it looks to me that the two primaries are connected in series.
Pic looks like TWO 115V primary's, one for each leg?. So looks
okay for 230V input to me.
"The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." George Orwell-1984
Edits: 12/05/19
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