<sg858585@[EMAIL PROTECTED]
> wrote in message
news:1cfdf4e6-1cad-49a6-83d8-64af9e7fc504@[EMAIL PROTECTED]
>i am working on a project called less current consuming led lamp,and
> the major idea of this project is less consumtion of current and
> compact in size.so i have planned to take out transformer ,which
> consume lot more space,so i want a help from u guys how to isolate the
> current from 230v/50hz supply to 12v dc supply with out
> transformer.were i am using a dimmer circuit but the current
> consumstion is more.the spefication of led is 12v/3watt.
>
> so i hope u help me out
take out transformer, put in capacitor. use flameproof resistor.
View in courier font.
500V flameproof 1W diode
LINE ----- 10uF ---- 1R ------o---->|----o-- 12V
- |
zener ^ 5W 12V 3.3mF
| |
NEUTRAL-----------------------o----------0-- GND
You can get 250mA at 12V out of it.
If you need a more regulated supply, use a 15V zener
and regulate the output with a 7812
Not sure this is cheaper than a transformer, though,
since the cap and zener are fairly expensive.
Regards,
Bob Monsen
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