PC SMPS as a test load for an active PFC

[technoqwerty123]

Hello,

I have designed a 250W boost active PFC with an output voltage of 400V. Is it safe to drive a standard 250W PC SMPS as a test load? Are the SMPS switches rated for this regulated Vin of 400V? The SMPS spec states an ac input of 120/230 Vac which transforms to a max 325V dc after rectification. Usually the design should acconut for a 20% safety margin while rating components. So it seems that the SMPS can safely sustain around 390V at its input. Any ideas?

Regards

 

[mtwieg]

I really doubt it will like a DC input. Often PC supplies these days have active or passive PFC built into them, so without an AC input they may not function at all. If this is not the case, and the PC supply just has a rectifier first and then an offline SMPS, then it might work. As for the voltage rating... hard to tell without knowing exactly what components the PC supply uses.

Why do you want to use the PC supply as a test load? What's wrong with a big resistor?

 

[technoqwerty123]

Hello mtwleg,
Thank You for your reply.
I have removed the frontend emi filter, rectifier and passive PFC components from the PC SMPS. I wish to use the SMPS as a load to study the active PFC's output voltage and input current control loop transient response. The PC SMPS, I believe, presents itself as a good transient real life load.

Regards