Hi Azhar
the most complicate item in a SMPS is the Xformer and Xformer design for a fly back type SMPS is much more tricky. Let’s first compare ferrite with laminated core.
Ferrite has lower eddy current,hut higher reluctance also has more linear hysteresist curve this made it more suitable for pulse operation and at hight frequency.
Now there are two types of SMPS the fly back and the square wave inverter type,both allow you to manipulate out put voltage in a limited range,and both give excellent regulation with wide IN PUT voltage level eg. Auto voltage supply in monitors and TV receivers gives you exactly 115 vdc out put when ac in put fluctuate from 90 to 240 acv but NOT the other way around, that’s the advantage of SMPS and if that’s what you has in mind then go SMPS !
The operating freq. affects the size of core mostly-same power smaller in size is the result of higher freq which meant higher in price. Rectifier and switch transistor for high frequency are much more expensive but if you must have SMPS then here goes:
Sart easy, if you want to learn micro you should buy or build a SBC then fiddle with it make a led lit up or blink etc…(like this old E Engineer is doing now !) in your case get an old power supply from the PC . an AT SMPS which used the TL494 power controller ic learn to make the xformer with it eg. Turn ratio, winding layers, remember they use full wave rectifier. Afterward get one using SG 3842 ic that’s your fly back ! now you will see all the trickiest part of the trade ! try to use MOSFET for the switch at hi freq they are cheaper. Mahmood knows where to find schematics for PC power supply ask him.
Happy fiddling.
Khanh
PS: my posts are mostly off date(due to can only read from mail list,I don’t browse much) but PLL basically works on PWM principle and that’s PULSE ! but if you intergrate a square wave you get a triangular wave if you intergrate this triangular wave you will get a sine wave, we either intergate or differentiate a wave to change the wave shape not filter them.Excellent ! you can measure caps and coils by using a well defined pulse of definite rise time/duration/fall time to gate a constant current source use to charge the caps or coil to be measure, the resulting dV/dt lets you predict the value, we E.Engineer use this principle to design distance ranging equipments and other sort of things.we only use perfect sine for freq conversion,distortion measurements applications