# Getting power for a dust sucker from multiple power supplies at the same time possible?

#### Leon_Chan

Joined Sep 11, 2019
99
Hi,
I bought a cheap hand held dust sucker rated 120W which got power from the car charger. The staff said it used 12V. I check some old dc chargers from my old monitors etc that provide 12V dc but it only provide about several amperes. So the sucker does not work in full as it does not have enough power. Is it possible I can wire up two such power supplies to make this sucker works? Or any alternatives?
Thanks

#### SamR

Joined Mar 19, 2019
5,020
which got power from the car charger
Are you trying to power it from an automotive battery charger?

#### Leon_Chan

Joined Sep 11, 2019
99
Are you trying to power it from an automotive battery charger?

#### musclesbenz

Joined Oct 14, 2016
11
Two 12v 1amp supplies is equivalent to one 12v 2amp supply.

#### Leon_Chan

Joined Sep 11, 2019
99
Two 12v 1amp supplies is equivalent to one 12v 2amp supply.
How that can possible be wired up?
I want to add up the amperes so the sucker would work.

#### SamR

Joined Mar 19, 2019
5,020
120W/12V = 10A so you need to find 10A somewhere...

#### Leon_Chan

Joined Sep 11, 2019
99
120W/12V = 10A so you need to find 10A somewhere...
I guess if connecting two such power supplies ( 240V ac, 12V dc max 4A output max may be ) in parallel would be possible?

#### Leon_Chan

Joined Sep 11, 2019
99
Another alternative I would think is to find an old desktop ATX switching power supplies that should be able to provide enough power at 12V for this.

#### SamR

Joined Mar 19, 2019
5,020
ATX power supply is at best 250W/120V = ~2A Look on eBay for used 12V power supply rated for over 10A. Typically used to power entire racks of servers and not just one desktop.
Something like this:

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#### ElectricSpidey

Joined Dec 2, 2017
2,753
Be sure to get an older ATX supply, most newer ones supply most of their current at 5 and 3.3 volts.

#### Leon_Chan

Joined Sep 11, 2019
99
Be sure to get an older ATX supply, most newer ones supply most of their current at 5 and 3.3 volts.
Thank you.
The world has changed. This mean that my knowledge of nowadays power switching box is outdated.

#### Leon_Chan

Joined Sep 11, 2019
99
Back to my original question in case connecting two power supplies in parallel would work , do I need to add a diode or other components too as the polarity may be connected in opposite, for example ?

#### SamR

Joined Mar 19, 2019
5,020
Wouldn't hurt not knowing what their circuit schematic looks like. Just don't forget the diodes forward drop.

#### Tonyr1084

Joined Sep 24, 2015
7,787
IF you had a 12V 1A supply connected in parallel with another one you would still have 12 volts but you would have 2 amps available. So if you had 10 of them in parallel you would still have 12V but 10A.

As for ATX power supplies: Here's a snapshot of my bench top (old computer) power supply. Notice it has +5V@22A, two 12V stages, both at 18A, a +3.3V@17A, another +5V@2A AND a -12V@1A. All my positive 12V outputs are paralleled for 36 amps, however, +12VA & 12VB combined is 264 watts. 264 ÷ 12V = 22A. I'm assuming I can't get the full 36 amps due to heat dissipation issues. Still, you can get more than 10 amps out of an ATX at 12V. At least the one on my bench top does.

Here's the ATX out of another computer - one I'm working on repairing (slowly):

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#### SamR

Joined Mar 19, 2019
5,020
Yes, but... Odd ratings...