Electronic – How to get higher amperage out of a power supply

amperageparallelpowerpower supply

I currently have a 24V – 5A power supply in a commercial product that may require upwards of 8A from the load. Ideally, I would just hook up another 24V – 5A power supply in parallel and not worry about the overcurrent. However, I know that this is an issue because of the slight differences in voltage from each power supply (they will fight til one dies).

Is there any way for me to boost the amperage available of this power supply safely without completely replacing it? Footprint is an issue since this is a commercial system, I have about 4" x 2" of space in my box.

For background, I am a degreed electrical engineer, but did not focus on circuit theory (went more of the emag/nuclear route).

Best Answer

If the power supply outputs can be put in series (i.e. their 0V ends can be "lifted" from ground) then you get 48V @5A and you can probably get a cheap off-the-shelf buck regulator that will convert down to 24V @9A. If you were designing from scratch I'd consider this part: -

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The above circuit is shown generating a 12V output from inputs ranging from 15V to 60V. If both power supplies are connectable to produce one at 48V then the above circuit, with ratio modification to the two resistors in the red box will easily produce 24V. However, I'm sure you could pick something up from a chines source or ebay for ~$10.

If they both have to be grounded then you could use a H-bridge driver chip where one half of the H bridge is powered from one supply whilst the other half is powered from the other 24 v supply. Maybe something like this.

Or you could have both supplies individually driving their own 12V flyback converters and wire the outputs in series (transformer outputs are used in flyback converters). This will work too.

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