SMPS power factor correction

[Mosaic]

I am getting around 0.68 PF from a Meanwell clone 36VDC 350W SMPS.
Is there anything reasonably simple to be done to improve that P.F.?

 

[AnalogKid]

There are passive power factor correction methods for power supplies, but they usually are integrated into the front end. Other than a very large series inductor, there is nothing "reasonably simple" that can be done external to the supply.

ak

 

[ronsimpson]

Simple answer is NO.

a very large series inductor

Adding that much inductance to a full wave rectifier will cause it to average not peak filter.
With out inductor; 110Vin ac, 150Vout dc.
With inductor; 110Vin ac, 110Vout dc.

 

[AnalogKid]

No, I'm talking about an inductor *before* the input bridge, in series with the incoming AC line. The question was about doing something simple, and I took that to mean something outside the purchased power supply.

ak

 

[ronsimpson]

I think the choke will "soften" the peak current.
The purpose is to have current flowing for most of the cycle. This will stop peak rectification.
Here is a pdf. It has a passive PF circuit that I have not used. see page 5. I have used boost PF circuits.
https://ac-dc.power.com/design-supp.../an-53-active-power-factor-correction-basics/

 

[tcmtech]

At 350 watt/VA why bother unless you are running 50 - 100 of these units at once?

 

[Mosaic]

At 350 watt/VA why bother unless you are running 50 - 100 of these units at once?

Because that is likely.

 

[tcmtech]

If you are running that many of these power supplies at once then going to a centralized PFC system would be a better solution.