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THE AM BULLETIN BOARD => Technical Forum => Topic started by: KB5MD on September 14, 2023, 01:12:34 AM

Title: Power supply hookup
Post by: KB5MD on September 14, 2023, 01:12:34 AM
If say a 60 amp supply and a 40 amp power supply are wired together in parallel, will the combination supply 100 amps?

Title: Re: Power supply hookup
Post by: Pete, WA2CWA on September 14, 2023, 02:48:43 AM
Not as easy as it sounds.

There needs to be some form of load sharing designed into each power supply at the very minimum. Some commercial power supplies are designed to do that but you need to check their specs.
Also, the output voltage of each supply needs to be identical (not close).

Let's say you have a 70 amp load. Without load sharing, you would max out the 40 amp supply first and probably/maybe send it into failure or develop shorted components. If 40 amp supply fails, the 60 amp supply would try to send all 60 amps to to the failed/shorted components(s). Not a good thing.

If you have a potential load that wants to draw 100 amps, you're better off and safer getting a power supply designed to provide 100 amp service. Or maybe even build one.

Title: Re: Power supply hookup
Post by: KD6VXI on September 14, 2023, 02:20:24 PM
You're best bet is to use the 40 or 60 as a battery charger and let a battery supply the extra oomph when needed.

This is how I used a Trip Lite 60A supply with an 8 x 2879 amp.


Edit:  Not all power supplies like having voltage on the output when turned off.   I blew my trip lite up originally doing this

I fixed it by putting a steering diode on the output and then moving the sense lead after the diode.

Title: Re: Power supply hookup
Post by: n8fvj on September 15, 2023, 05:43:51 AM
Lowest cost here: ebay item number 314754342776 New power supply for $88 shipped to USA. Rated 100 amp at 12 volt power supply. I think it can only be adjusted up to 12.6 to perhaps 13.2 volts.
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