Hi all,

I'm having a weird issue here - I have 2off 24V power supplies each bridged together in a load-share configuration using diodes to supply an SBC. The SBC can run off a wide range input from 9V to 36V.

I find, however, that when I use the inline diodes on the power supply, the SBC doesn't power up and I can't figure out why. I thought there might be a voltage drop across the diode but this should be well within the acceptable range, so my only other guess is that there's a resistance in the diode which is limiting the current? Is this a known problem? Simple diagram attached.

The diodes are there to allow for some redundancy - if one supply gets a short-circuit over the output then the other will still be able to function.

 

What Diodes are you using, 1N4001, 1N54001, or Schokley diodes?

 

Try a smoothing capacitor after the diodes as the diodes kinda isolate the capacitors in the power supplies.

 

The diagram show isolated supplies. Are you sure that your supplies are truly isolated?

 

Thanks for the input so soon folks, but it turns out my diodes were actually bust and just open circuit - serves me right for not properly testing!

Edit: now I can't edit my OP or close the thread - if a mod could do that for me it'd be much appreciated!