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Comment by snops | Hacker News Reader

Having needed something like this recently, I would recommend utilising 48V-12V convertors designed for servers. Telecoms equipment has long been 48V (actually -48V) but some datacenters are moving that way too for internal distribution.

There are some automotive designs for 48-12V conversation, but these are not really available as modules as automotive is large volume and high integration. Using discrete components gets expensive fast at these power levels, a Renesas 2KW reference design I saw needed a 4 layer, 6oz PCB which would have cost ~$500 to prototype in China.

The Vicor BCM series can do 48V->12V 150A out in a very nice self contained module, with excellent EMI shielding, and takes cables directly, although definitely needs a heatsink! http://www.vicorpower.com/products?productType=cfg&productKe...

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Blade Chassis power supplies are cheap used, very efficient, and will do nearly 200A at 12V from 240V input.

Search HP 500242-001.

I'll second that, I believe people use them for RC chargers sometimes. I used the HP DPS 600PB for trying to drive a number of peltiers. I think mine only did less than 50A, will look into the model you mentioned.

I assume none of the blade PSUs also output 5VDC?

If you can pick up a DS850-5 it'll give you 12v @ 70A and 5v @ 4A. It'll have noisy fans that run constantly, though.

Most applications of such a power supply (like blade servers) would have a bunch of secondary SMPSes generating lower voltages from the 12v rail.

I have 5 at home, exactly from a Blade Center.

Any idea what I can do with them?

Designing CPU power supplies that are efficient and are not just a great lot of buck converters in different phases (VRMs) is very hard.

On modern CPU that are all running at at around 1V, you get 1 amp = 1 watt

Switching element must survive that, and you have to be super responsive to transients, and you have to have super low ripple... I do not envy guys who make VRMs for GPUs and 200w server chips

What did you need so many amps for? My imagination falls short of melting things (like OP did).

Switchgear testing, for HighVoltage (~110KV++) or MediumVoltage (~10KV to 110) you usually will test only the secondary side, for LowVoltage (~400V -10KV)you can test the Breaker with a primary source, these Breakers range from 100A to 5000A.

But then you would need IGBT's not MOSFET converters.

Powering some 12V motors for a robot from a 48V tether supply.

Quite easy to get into hundreds of watts with relatively small brushless motors, the type that would normally be used in hobby RC, powered from LiPos. The Vicor parts have a good amount of protection circuitry as well, useful when shorted wires can start glowing very quickly, and RC lipo packs have no protection at all.

Galvanoplasty, electrolysis, and many other electricity-dependent chemical reactions, strong electromagnets and small wire-length actuators (like rail guns).

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