Need power supply design, 9VDC, 100mA, no transformer

[Bus Master]

Hi all,

Any body can help in this design quiz? I need a power supply unit with output 9VDC, 100mA without tranformer, it must operate from mains supply (220VAC / 50 Hz).

This is urgent. Anybody can help?

Thanks in advance.

Yours,

 

[IanP]

This power supply will be without isolation:
Connect 1.5µF( at 50Hz this will give you about 2100Ω impedance) from 220Vac(active) in series with a rectifing bridge and Neutral; to the output of the bridge connect a smoothing capacitor, say, 1000µF in parallel with 9.1V zener diode. This is your 9V output.

 

[glenjoy]

This power supply will be without isolation:
Connect 1.5µF( at 50Hz this will give you about 2100Ω impedance) from 220Vac(active) in series with a rectifing bridge and Neutral; to the output of the bridge connect a smoothing capacitor, say, 1000µF in parallel with 9.1V zener diode. This is your 9V output.

Will it be safe to touch the 9V output of it? I don't think so.

 

[nicleo]

You can consider Offline SMPS. The transformer used in Offline SMPS is very much smaller. Try to look at those modern handphone chargers, they're light and small. And, you will have isolation from high voltage for safety purpose.

 

[fuzzy]

Please download AN954 from w*w.microchip.com web site