ATX-725B - start load ?

[perseus142]

Hello guys,

I found an old ATX power supply which I would like to use as cheap power source of 5V and 12 V.
It has been working fine after I short green-black wires to start up it and plug 10 ohm/5W resistor as load to 5V/26A rail (red-black wires).

However after a minute this resistor became hot.
Without the resistor the power supply will not start.
I havent found a datasheet for this power supply.

Could you advise me a resonable resistor load and tell me how to estimate the value ?

Enlight Corporation
ATX-725B 250W
Picture attached.

Thank you.

[cpt.charlie]

Re: ATX-725B - start load ?

A 10 ohm at 5V it's dissipating 2.5Watt, of course it will get "hot"

[perseus142]

Re: ATX-725B - start load ?

A 10 ohm at 5V it's dissipating 2.5Watt, of course it will get "hot"

Exactly. Ohms law.

From your experience,what resistor value (ohms,watts) would you recommend in order to use safetely this ATX power supply as cheap lab bench power supply ?

[cpt.charlie]

Re: ATX-725B - start load ?

Likely a 5-10 watt load should be enough, but maybe with your current setup might work just fine, it depends of every particular PSU.