Regarding 12Vdc SMPS load testing at o/p

[htcompany]

Hello to all,
i have SMPS of i/p:230Vac and o/p:12Vdc. the maximum output current is 0.8A. Now i want to test the SMPS with load connected at o/p by continous keeping SMPS ON. By calculation,
R = V/I, where V=12Vdc and I=0.8A; i connected 15 ohm (2watt) resistor as a load at output side, but after 5min it got burnt. Is my calculation correct for resistor value 15 ohm(2watt) ? what should i do to test my SMPS for load ?




Regards...

 

[KlausST]

Hi,

P = U x U / R = 12V x 12V / 15 Ohms
It´s way more than 2W.

Klaus

 

[BradtheRad]

by continous keeping SMPS ON.

Conceivably it can happen by accident. Therefore a fuse is a good method to protect your project. It might sound like a good idea to test by creating continuous-On condition intentionally, but it also is a way to burn up components.

Can you test by making the duty cycle longer, gradually? Then monitor all components, to see if anything bad starts to develop.

For a buck converter, continuous-On means you get high voltage at the output.

For a flyback, continuous-On means zero output voltage, and possibly extreme current level through a transformer.