SMPS - Switching Mode Power Supplies - Any example ?

[flotulopex]

Hello,

I need to power a circuit I made with the main's AC. This because I use it's frequency (50Hz in Europe) to clock my PIC. My circuit draws around 50mA (mainly due to the 7-Seg 4-Digit LED display).

Using a transformer is very easy but extremeley unefficient regarding space and power dissipation.

I've heard quite a lot about SMPS (Switching Mode Power Supplies).

There are lots of theoretical documents about this subject but, unfortunately, I couldn't find at least one electronic shema example about this.

Does anyone know where I could find this kind of information?

[HenrikOlsson]

Hi,
Perhaps you should take a look at Microchip AN954. May or may not work with that much current. Be careful!

/Henrik Olsson.

[mister_e]

depending your current requirement, you may find some already built one fore few bucks. i don't think they even need to be design in most case.

Most company have some SMPS controller IC as well. worth to have a look there.

[flotulopex]

Hello Mister_E,

Would you have one or more links to these components please? I must not search the right way (correct words) since I can't find anything.

By the way, what do you use (what would you use) in this case?

Thank you HenrikOlsson, I read this application note already. Unfortunately, this kind of power supply allows only extremeley narrow min/max power ranges.

[mister_e]

How much current do you need?

[flotulopex]

I need around 0,05mA.

Input voltage is 230VAC 50Hz (Europe).