Author Topic: JP 12V 10A switching PSU only producing about 5 volts  (Read 2285 times)

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Offline netdudeuk

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #25 on: April 17, 2018, 11:59:33 pm »
as noted   you have cold joint solder on the two to220 transistors / rectifiers  and som in the middle of the board, you see small rounds in the solders .... redo the board at first before anything else ...  and im sure it is not an 10 amps psu   or its the wrong fuse at 7.5 amps on the pcb ??

I'll do that thanks.

Interesting that the 12 volts 10 amps PSU puts out 14 volts under load at no more than 7.5 amps.  The PCB legend, the fuse and the manual (http://airtekhobbies.com/downloads/jpultrapower.pdf) all say 7.5 amps.




 

Offline Rasz

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #26 on: April 18, 2018, 11:50:09 am »
as noted   you have cold joint solder on the two to220 transistors / rectifiers  and som in the middle of the board, you see small rounds in the solders .... redo the board at first before anything else ...  and im sure it is not an 10 amps psu   or its the wrong fuse at 7.5 amps on the pcb ??

I'll do that thanks.

Interesting that the 12 volts 10 amps PSU puts out 14 volts under load at no more than 7.5 amps.  The PCB legend, the fuse and the manual (http://airtekhobbies.com/downloads/jpultrapower.pdf) all say 7.5 amps.

its normal, those are Chinese amps
people already told you its a noname garbage, and no, 'jp ultrapower' is not a brand :)
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Offline netdudeuk

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #27 on: April 18, 2018, 12:03:17 pm »
as noted   you have cold joint solder on the two to220 transistors / rectifiers  and som in the middle of the board, you see small rounds in the solders .... redo the board at first before anything else ...  and im sure it is not an 10 amps psu   or its the wrong fuse at 7.5 amps on the pcb ??

I'll do that thanks.

Interesting that the 12 volts 10 amps PSU puts out 14 volts under load at no more than 7.5 amps.  The PCB legend, the fuse and the manual (http://airtekhobbies.com/downloads/jpultrapower.pdf) all say 7.5 amps.


'jp ultrapower' is not a brand :)

No, but J Perkins is  ;)

http://jperkins.com/
 

Offline LateLesley

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #28 on: April 18, 2018, 12:38:17 pm »
NetdudeUK,

I'm not saying this to be nasty or anything, or to discourage you from repairing things, but there is a reason many in this thread have been telling you to just bin this PSU. IT is NOT a quality made PSU, no matter the branding on it. You only need to look at the supply to see that. Things you would look for in a quality supply is input filtering with inductors, X rated and Y rated capacitors, and some protection circuitry, of which this has none, bar a fuse - which also happens to be in the neutral line. If that fuse blows, the unit could still be live, and KILL YOU. It is a danger, and a fire hazard.

I do commend you trying to fix things, but please also learn when it is worth fixing something, and when to just burn it with fire. Do yourself a favour, and strip it apart, salvage the good components for you to play around with in low voltage projects, and buy yourself a quality PSU which won't kill you if something goes wrong.

I only say this in the interest of your own safety.

Theres many videos about on PSUs and ones which are dangerous. Here's one example.
 
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Offline netdudeuk

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #29 on: April 18, 2018, 01:12:27 pm »
Thanks for the reply.  I've seen a few Big Clive videos, as per my previous comment.

I have another PSU ;)

 

Offline LateLesley

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #30 on: April 18, 2018, 01:36:06 pm »
oooooo! Fancy! I'm well jealous! lol! That PSU looks awesome.

I've got one of those cheap chinese PSU's, a QW-MS3010D - it's not very accurate and a bit clunky, but it does for what i'm doing, just messing about with stuff, or powering up rails in equipment to find faults. I just make sure to set it with a meter beforehand. :) https://www.image-tmart.com/prodimgs_v2/8/8802/1713/88021713/QWMS3010D-30V-10A-Adjustable-DC-Stabilizer-Power-Supply-EU-Standard-White_800x800.jpg?1469780213

I also recently got my hands on a wee DPS3003, and it's a cracking wee power supply for the money. I use it in conjunction with my MS3010D when I need a bit finer control of voltage and current. And it's great. I highly recommend it. It does need an external PSU to go with it right enough, but for poor folk like me, it's brill.
 

Offline bd139

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #31 on: April 18, 2018, 01:55:12 pm »
If you want some cheap but decent quality bench supplies Look out for Thurlby PL series supplies on ebay. Can score proper bench supplies for £30/40 a pop. I've got a PL154 (15V 4A) and PL310 (30V 1A).

https://www.ebay.co.uk/sch/i.html?_sacat=0&_sop=15&_nkw=thurlby%20power%20supply&LH_Complete=1&LH_Sold=1&rt=nc&_trksid=p2045573.m1684

Avoid the black and white ones though. The grey ones are top notch however. Better quality than anything HP knocked out for a number of years. Virtually impossible to blow up - they will handle a dead short or running at full load 100% duty cycle all day every day for a decade and just carry on.
« Last Edit: April 18, 2018, 01:57:20 pm by bd139 »
 
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Offline LateLesley

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #32 on: April 18, 2018, 02:10:57 pm »
Thanks BD139. I may just do that at some point, once I get my workbench built. I've been procrastinating for a long time (I suffer from depression) but I'm hoping to get a work area built in the back of my kitchen (I live in an old Glasgow tenement, it's the old bed recess from the old room n kitchen setup). I'm currently faffing about building a couple of kitchen units, and got a bit of worktop to cut which will sit across them, and be my work area. Then on the list is to get a cheap oscilloscope, and start getting through a lot of unfinished projects I have laying around. I'm just trying to get my passion for electronics back, and build up my confidence again. I've had it knocked a lot in recent years.

Thanks for the advice though, its good to know from folk with experience. (I just need to figure out now what you mean about the Black/white/grey ones, I cannae tell the difference, except the front panels look slightly different, either two-tone, or pretty solid color apart from the displays.  :-DD ) Thanks again.
 

Offline bd139

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #33 on: April 18, 2018, 03:02:03 pm »
Been there so completely understand the confidence thing. I had a long hiatus from electronics from about 2001-2010 I think it was.

Have a look at the following thread: https://www.eevblog.com/forum/testgear/tti-thurbly-thandar-and-age-of-older-models/ ... horrid ones are the one with the black band and brown cases. There's grey knobs and a push button switch for the current damping on the good ones.

 
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Offline Rasz

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Re: JP 12V 10A switching PSU only producing about 5 volts
« Reply #34 on: April 18, 2018, 08:42:25 pm »
as noted   you have cold joint solder on the two to220 transistors / rectifiers  and som in the middle of the board, you see small rounds in the solders .... redo the board at first before anything else ...  and im sure it is not an 10 amps psu   or its the wrong fuse at 7.5 amps on the pcb ??

I'll do that thanks.

Interesting that the 12 volts 10 amps PSU puts out 14 volts under load at no more than 7.5 amps.  The PCB legend, the fuse and the manual (http://airtekhobbies.com/downloads/jpultrapower.pdf) all say 7.5 amps.


'jp ultrapower' is not a brand :)

No, but J Perkins is  ;)

http://jperkins.com/

Yes, J Perkins is distributor, not a manufacturing company, they just slapped their own label on ..chinese garbage :( and lied about true parameters in the process, seems very reputable.
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 


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