Power supply... help .... ?

Hello friends.... welcome ....

Friend I have nokia charger circuit which delivers 4volt dc and 500 Milli ampere current.... and I want to convert this to 12 volt dc and 100 milli ampere current...

kindly help.
Jammy

Go to www.national.com than open the Webench Designer, enter your data and 10+ designs (c/w schematic, partslist and performance) will be displayed. E

SMPS with TL494 (230V/+/-35V/2x5A)

Hello all!
I need projecat or schematic with TL494 (KA7500) for the SMPS for +/-35V/2x5A.
Thanks

I think a simple MC34063 circuit will do the job, if you don't care too much about ripple, it's robust and low cost.
check out MC34063 datasheet here :
https://www.alldatasheet.com/datasheet-pdf/pdf/92958/STMICROELECTRONICS/MC34063.html

Jammy said:

which delivers 4volt dc and 500 Milli ampere current.... and I want to convert this to 12 volt dc and 100 milli ampere current...

Click to expand...

efficiency...

I'd stash the Nokia, it's a great P.S. for a 3.3V project. That, and by the time you take it apart, trace it and modify it, you'll have built 2 from scratch.
Cell phone chargers are a real boon to project builders (most of us here). They're small, efficient, well regulated and people give'em away on upgrades/breakages.
For 12V @ 100mA, I'd take a 14+VDC wall xfmr and put a 7812 with a couple of caps in a box. <<<)))