Need to convert 440vac to 5vdc without transformer

[ragav4456]

Hi

I need to measure 440 ac voltage by using ADC. i need convert 440vac to 5vdc, kindly help me.

Thanks
Parthiban

 

[rahol]

hii

you simply want to convert the voltage from ac to dc 5v .. better used step-down transformer that gives you 440ac to 12v dc and then use voltage regulator LM7805 to convert it from 12v to 5 v dc

 

[nandhu015]

Resistor voltage divider..

 

[bigbop]

Since you want to measure it using an ADC which will most likely be connected to something else, you need to electrically isolate the high voltage from the low voltage.
You can do this using high voltage capacitors in a similar voltage divider network to a resistor voltage divider network.
You'll need to calculate how much current you'll need and the frequency of the Ac source to determine the actual uF values using non-polarised caps. Then, pull off and rectify the output.
Try some experimentation with this setup.