I'm using some of those cheap eBay smps power supplies to drive a bunch of LEDs which are controlled via pwm with and arduino ... And I was wondering what is the best method to handle the power supply... Basically are caps good or bad? Bigger or smaller ...?
I haven't been able to find much info discussing the different considerations, but it seems like the ideal cap size is just large enough to reduce the ripple to an acceptable level, so small sizes around 10uf would be sufficient ( small sizes are effective because of the switching frequency) so are big caps bad or just unnecessary? I suppose large caps act like shorts until they are charged ... But they help absorb peak demands, however the power supply should generally be sized properly to handle that ...
Which leads me to another question, is there an ideal frequency ratio of pwm to switching frequency? I don't suppose they would get into some kind of weird harmonics ?
What are your experiences ?