5 volt dc circuit without using transformer

[amanpreetk]

Hi,
I want to make a circuit in which I need 3-5 volts supply for ADC of ATMEGA16 from the mains supply voltage of 230 volts AC.I am trying to make a circuit without the need of stepping down the voltage through a transformer.Is there any circuit that I can use for my convenience (a circuit in which I can achieve 3-5 volts without using transformer) ?

 

[ysba]

Check this out:

https://ww1.microchip.com/downloads/en/AppNotes/00954A.pdf

 

[amanpreetk]

Check this out:

https://ww1.microchip.com/downloads/en/AppNotes/00954A.pdf

Hi,
Thanks for the useful information.
I tried making the above circuits but voltage output that I am getting is not stable, it keeps on increasing continuously.
For eg. if voltage output in the beginning is 4.80 volts, it keeps on increasing to 4.81, 4.82 and so on... after every 1 or 2 seconds, to approximately 5 volts. Is there any method so that I can get a stable voltage without adding .01 volts after every 1 second?

 

[chuckey]

The increase in voltage is literally because the components are warming up to their final values. Choose better components and the problem will go.
Frank

 

[mtwieg]

Required reading for anyone building transformerless supplies:

**broken link removed**