I just want to convert 220 AC to 5-12V DC, without using bulky and havy 50 hertz transformator but still separate between 2 phases (so I do not want to use a tiristor.
So I want to convert using hi frequency transformer
To avoid a 50Hz transformer you would rectify the raw AC to DC using a bridge rectifier and then use a DC-DC converter with a transformer that is configured to give an isolated output.
If it's just for learning, I would not try to go directly from mains the first time. Get a power transformer with a 24 or 36v output to "simulate" mains without being quite so dangerous.
Research and build the subcircuits in this order...
1. Variable duty PWM controller
2. Buck circuit
3. Output voltage feeback
4. Output current feedback
This site has so many threads on PWM controllers you shouldn't need to go elsewhere. The buck circuit is simple and you'll find 100's of references on google. The feedback circuits can get a little tricky, but get the first two sections working first.
If it's just for learning, I would not try to go directly from mains the first time. Get a power transformer with a 24 or 36v output to "simulate" mains without being quite so dangerous.
Research and build the subcircuits in this order...
1. Variable duty PWM controller
2. Buck circuit
3. Output voltage feeback
4. Output current feedback
This site has so many threads on PWM controllers you shouldn't need to go elsewhere. The buck circuit is simple and you'll find 100's of references on google. The feedback circuits can get a little tricky, but get the first two sections working first.
Sangel, if you don't know exactly what you're doing 220V is not fun, it's dead. Be very sure you know what you're doing, connected incorrectly to 220V's directly most components will explode violently, even if they ARE connected correctly sometimes things go wrong.
Sangel, if you don't know exactly what you're doing 220V is not fun, it's dead. Be very sure you know what you're doing, connected incorrectly to 220V's directly most components will explode violently, even if they ARE connected correctly sometimes things go wrong.
The simplest 1 transistor solution is the power supply of the 12" BW Indesit TV built in the 70's, it was using germanium transitor and the line transformer.
I couldn't find the diagram though...
allegro, no one gave him a schematic because there are hundreds on the net already and we've been getting posts just like this twice a week or more. If the poster is serious about his project he'll use Google for 20 minutes find a few circuits and come back asking for suggestions on them. We can't do all the research for EVERYone here if they don't put a first step forward. And asking for a circuit is not a first step forward. This board is here to help people and collaborate on projects, not do them for you.