12V 10Amps Power Supply Works for 5 Minutes Only

[Nauman Muhammad]

Hi Guys,

I bought a new 12v 10Amp power supply but it's giving me the issue that it stops after 5 minutes. By stopping I mean it doesn't completely stops it just start blinking the fan (motor) and also the fan inside the power supply. I have tried it with two different 12v motors. Please suggest me solution. What to check? How to check? and what might needs replacement.

 

[bertus]

Hello,

I see you have a metal strip over the transformer.
That might influence the working of the transformer.
What does the powersupply do without that strip?

Bertus

 

[Nauman Muhammad]

Hi Bertus,

Thanks for the reply. It's there just to hold the circuit. And it's a locally made power supply so it's possible that there might a design flaw. Shall I remove that?

Hello,

I see you have a metal strip over the transformer.
That might influence the working of the transformer.
What does the powersupply do without that strip?

Bertus

 

[Nauman Muhammad]

I also notices one thing unusual just now that when power supply is started without load, fan inside it initially moves clockwise, then stops and starts moving anti clock wise and the continue movie until it fails!

 

[bertus]

Hello,

The strip over the transformer might influence the specs of the transformer.
Remove it and see if it keeps working.
If so, better try an other way of fixing the powersupply in the case.

SMPS powersupplies usualy need a minimum current as load.
Without the minimum load the working can not be garanteed.
You should read the spctifications of the power supply waht this minimum load is.

Bertus

 

[73's de Edd]

Sir Nauman Muhammad . . . . .long time no see . . . .

The strip over the transformer might influence the specs of the transformer.

In the plane that it is is being mounted in and its positioning in respect to the windings direction, along with it not being encircled into a fully complete one turn closed loop . . . I really tend to dismiss that consideration

I do wonder more about the assymetry of Casper Pee Clodds "hand bent" fabication of that clamp and the final screw downs non uniformity of tension being applied to that ferrite core with a skewed pressure then exerted against the ferrite core . . . . . . and any future overheating / mechanical core expansiion of the transformer resulting in . . . . . c . . . r . . . a . . . c . . . k.

How old and how much use time has this " new" power supply received ?
My only clue might be the amount of dust that already has accumuated on the fan blade, so its not being just fresh out of the box.

If having tried its running two different 12VDC motors ( for home cooling fans ? )what current or wattage do they consume ?
As for this being an in " Pakistani " manufactured item . . . . . . . .no . . . . what I am SEEING HERE , within its electronics design realm, is being a Chinese sourced power supply that was

" put in a plastic box, two power input and output leads connected and then a cooling fan installed in one half of the box "

That actual power supply also seems to be under built and over rated for adequately qualifying for a 12VDC @ 10 Amp . . . .120 watts . . . . .specification.
The meager power transformer core mass seems to only be a bit more that the common contrawound inductor located over near the AC power cord input.
Also the output sections E-caps amounts seem to be undervalued.

Lets try this, if you can get the unit operating a fan again successfully . . . . .run the unit until it stops working and then rapidly unplug it from the AC power and quickly use fingers being touched . . . . one item at a time . . . to the power transformers ferrite core and the two aluminum heat sinks to see which one(s) might be running hot ..
Thus differentiating between a component malfunction . . .all relatively new and unlikely . . .or an under rated PS board . . . .if you are pulling up towards the 10 amp level.

CURIOSITY ? . . . . .
Look at the power supply sections case half that has the 4 round bosses in the corners . . . with all being pristine.
Look at the case half with the fan, all of the four bosses on that half are being split, sheared off or cracked ... Yours or the manufacturers fault ?

73's de Edd . . . . . .


.

 

[WHONOES]

Looks as though it is using a secondary regulator on a small heatsink. These tend to have over temp cut outs to protect them. it could be that it is simply over heating.

 

[Nauman Muhammad]

I am very glad to see your response Edd.

First of all let me answer your questions:

How old and how much use time has this " new" power supply received ? - It's new and when I used first time, it did that!
My only clue might be the amount of dust that already has accumuated on the fan blade, so its not being just fresh out of the box.

If having tried its running two different 12VDC motors ( for home cooling fans ? )what current or wattage do they consume ? Actually this motor is rated for 7 Amps and one water pump is of 1 Amp.

Look at the power supply sections case half that has the 4 round bosses in the corners . . . with all being pristine.
Look at the case half with the fan, all of the four bosses on that half are being split, sheared off or cracked ... Yours or the manufacturers fault ? - I did that, since nuts were glued as well

Now I am in other situation that if I pull out same motor from the room cooler it works perfectly fine, also same supply is working totally fine with another room cooler. Room cooler doesn't have any circuits, it's simply connected with power supply/ solar panel (directly). Can fitting of motor cause something to fail the supply? or can add some magnetic fields?

And power supply of that another cooler is working perfectly fine with this room cooler. So now though my issue is resolved but I cannot understand what that power supply doesn't work when used with motor fitted in that specific room cooler. :/

Sir Nauman Muhammad . . . . .long time no see . . . .



In the plane that it is is being mounted in and its positioning in respect to the windings direction, along with it not being encircled into a fully complete one turn closed loop . . . I really tend to dismiss that consideration

I do wonder more about the assymetry of Casper Pee Clodds "hand bent" fabication of that clamp and the final screw downs non uniformity of tension being applied to that ferrite core with a skewed pressure then exerted against the ferrite core . . . . . . and any future overheating / mechanical core expansiion of the transformer resulting in . . . . . c . . . r . . . a . . . c . . . k.

How old and how much use time has this " new" power supply received ?
My only clue might be the amount of dust that already has accumuated on the fan blade, so its not being just fresh out of the box.

If having tried its running two different 12VDC motors ( for home cooling fans ? )what current or wattage do they consume ?
As for this being an in " Pakistani " manufactured item . . . . . . . .no . . . . what I am SEEING HERE , within its electronics design realm, is being a Chinese sourced power supply that was

" put in a plastic box, two power input and output leads connected and then a cooling fan installed in one half of the box "

That actual power supply also seems to be under built and over rated for adequately qualifying for a 12VDC @ 10 Amp . . . .120 watts . . . . .specification.
The meager power transformer core mass seems to only be a bit more that the common contrawound inductor located over near the AC power cord input.
Also the output sections E-caps amounts seem to be undervalued.

Lets try this, if you can get the unit operating a fan again successfully . . . . .run the unit until it stops working and then rapidly unplug it from the AC power and quickly use fingers being touched . . . . one item at a time . . . to the power transformers ferrite core and the two aluminum heat sinks to see which one(s) might be running hot ..
Thus differentiating between a component malfunction . . .all relatively new and unlikely . . .or an under rated PS board . . . .if you are pulling up towards the 10 amp level.

CURIOSITY ? . . . . .
Look at the power supply sections case half that has the 4 round bosses in the corners . . . with all being pristine.
Look at the case half with the fan, all of the four bosses on that half are being split, sheared off or cracked ... Yours or the manufacturers fault ?

73's de Edd . . . . . .


.

 

[Nauman Muhammad]

Looks as though it is using a secondary regulator on a small heatsink. These tend to have over temp cut outs to protect them. it could be that it is simply over heating.

I tried to check if it's over heating or not but the air from exhaust fan of the supply is of normal temp. Can it still be overheated?

 

[WHONOES]

Can you see the markings on the heatsink mounted devices.