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Repurposing a Dell power brick

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bob prohaska

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Jun 12, 2022, 6:23:02 PM6/12/22
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I have a Dell AC power adapter, model ADP-150BB B
which I'd like to re-purpose as a 12 volt power supply.
It's rated 12 volts 12.5 amps, which might make a good
battery charger.

It worked when last used to run a computer, but plugged
in by itself the power LED doesn't come on. The case is
closed by anti-tamper Torx screws, suggesting some sort
of trickery will be needed to make it run.

On checking the pinout, there's a "remote" terminal in
the connector, further suggesting Dell has somehow keyed
the adapter to the computer.

Does anybody happen to know to get it to turn on? I'd
really like to keep it out of e-waste. There's nothing
to lose, so I don't mind opening it up if that will be
helpful. It's useless now, there's nothing to lose.

Thanks for reading,

bob prohaska



Adrian Caspersz

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Jun 12, 2022, 6:37:25 PM6/12/22
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On 12/06/2022 23:22, bob prohaska wrote:
> I have a Dell AC power adapter, model ADP-150BB B
> which I'd like to re-purpose as a 12 volt power supply.
> It's rated 12 volts 12.5 amps, which might make a good
> battery charger.

Charging what voltage battery?

You may need to raise the output voltage a bit if you are thinking of
charging a 12V battery with it.

https://batteryuniversity.com/

> It worked when last used to run a computer, but plugged
> in by itself the power LED doesn't come on. The case is
> closed by anti-tamper Torx screws, suggesting some sort
> of trickery will be needed to make it run.

Some SMPS need a minimum load to start. You might find without that, you
won't find an open circuit voltage to measure.

I used to use a "boat anchor" type MFM hard disk drive as my start up
load, but that was years ago.

Also, think about adding fuses in series with what you add to it.

--
Adrian C

bob prohaska

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Jun 12, 2022, 9:24:54 PM6/12/22
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Adrian Caspersz <em...@here.invalid> wrote:
> On 12/06/2022 23:22, bob prohaska wrote:
>> I have a Dell AC power adapter, model ADP-150BB B
>> which I'd like to re-purpose as a 12 volt power supply.
>> It's rated 12 volts 12.5 amps, which might make a good
>> battery charger.
>
> Charging what voltage battery?

12 volt nominal, if it can do 13 volts that would be useful.

>
> You may need to raise the output voltage a bit if you are thinking of
> charging a 12V battery with it.
>

Indeed, there's what looks like a trimpot inside the case. It turns out
the anti-tamper screws were defeated by a small flat screwdriver jammed
between one spline and the center post.

>
> Some SMPS need a minimum load to start. You might find without that, you
> won't find an open circuit voltage to measure.
>

Just tried a lightbulb with ~2.3 ohm cold resistance across the
output. Nothing.

After a bit of fumbling, it turns out the "remote" line needs
to be pulled to ground, which puts 11.99 volts on the output.
That's lower than I'd hoped, but it's a good start. The unit
looks nicely made, it would be pleasing to salvage it.

Thanks for writing!

bob prohaska

Turd Ferguson

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Jun 13, 2022, 5:26:56 PM6/13/22
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bob prohaska

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Jun 13, 2022, 8:48:48 PM6/13/22
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That's the unit I have. The adjuster that I thought might be for
voltage seems to have no effect, leaving the no-load output at
11.99 volts and loaded (auto tail light bulb) at 11.3. That's too
low for my application, which requires at least 13.5 volts to be
useful. Maybe I'm doing something wrong, but it looks as if my luck
has run out.

Thanks for writing,

bob prohaska



Tom Biasi

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Jun 14, 2022, 12:23:30 AM6/14/22
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On 6/12/2022 9:24 PM, bob prohaska wrote:
Its not a battery charger its a very well regulated 12 volt supply. Do
yourself and the batteries a favor and get a battery charger.

Adrian Caspersz

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Jun 15, 2022, 5:52:51 AM6/15/22
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On 14/06/2022 01:48, bob prohaska wrote:

> That's the unit I have. The adjuster that I thought might be for
> voltage seems to have no effect, leaving the no-load output at
> 11.99 volts and loaded (auto tail light bulb) at 11.3. That's too
> low for my application, which requires at least 13.5 volts to be
> useful. Maybe I'm doing something wrong, but it looks as if my luck
> has run out.

Plenty of vids on youtube if you search for

smps increase voltage

or similar.

> Thanks for writing,
>
> bob prohaska

Take care, one hand in pocket etc...

--
Adrian C

Peter W.

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Jun 15, 2022, 8:25:24 AM6/15/22
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Whereas I value and appreciate repurposing all sorts of devices, when it comes to battery charges, I tend to draw the line, as much by class as use:

a) Lead Acid batteries store a tremendous amount of energy using dangerous chemicals that if released suddenly can (and will) cause massive physical as well as environmental damage. With this class of batteries, I try to use only 'smart' chargers designed for the purpose and intent. Nor do they like being over-charged.
b) Gel Cells (Gates Trademark) tend to be more stable than the typical lead-acid battery, but really do not like being overcharged. They, too, can explode.
c) Lithium batteries in their various types - as above, with a curious ability to burst into flames if abused.
d) Ni/Cd batteries, while quite tolerant of high charging voltages - initially - do not like to be overcharged, and can be damaged in that process.

You pays you money, you takes you chances.

Peter Wieck
Melrose Park, PA

ohg...@gmail.com

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Jun 15, 2022, 9:44:58 AM6/15/22
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ohg...@gmail.com

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Jun 15, 2022, 9:48:18 AM6/15/22
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On Sunday, June 12, 2022 at 6:23:02 PM UTC-4, bob prohaska wrote:
You will still need a battery charger circuit added to your brute supply to become a battery charger.

I've repurposed a bunch of wall bricks by changing the fixed voltage they normally run at. Find the smps controller IC on the board and get a datasheet on line. With that, you'll get a representative circuit that will show you the feedback circuit and associated input pin. Fudge resistor values from the opto coupler to the feedback pin to adjust the 12V output. On some, I've added a trimmer to adjust the value as needed.

bob prohaska

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Jun 15, 2022, 8:41:37 PM6/15/22
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ohg...@gmail.com <ohg...@gmail.com> wrote:
> On Sunday, June 12, 2022 at 6:23:02 PM UTC-4, bob prohaska wrote:
>> I have a Dell AC power adapter, model ADP-150BB B
>> which I'd like to re-purpose as a 12 volt power supply.
>> It's rated 12 volts 12.5 amps, which might make a good
>> battery charger.
>>
>
> You will still need a battery charger circuit added to your brute supply to become a battery charger.

I shouldn't have called it a battery "charger". "Booster" would have been a
more accurate term. It'd be set to, say, 13.8 volts with the actual CC/CV
charger set to 14.4 volts. That way it could add a little extra current
in the early phase of charging and then become insignificant at the end.

It's too tightly packaged to be easily modified. Can't even get a good
look at the board without taking the heatsinks off. I'll look elsewhere....

Thanks for writing,

bob prohaska


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