Obtaining 5v from 220v...

[JAMAL JIMI]

Hi....everyone....
Is it possible obtain 5vdc from 220 vac by first converting the ac voltage to dc and then by giving this voltage to two mosfets connected in series and then giving pwm of about 5% duty cycle to both of them...

 

[kam1787]

yes BUT while the average voltage might be 5V the peak voltage will be very high - depending on whether you rectify using half-wave or full wave

you could not use it as a generic 5V

 

[JAMAL JIMI]

Then how can i convert this type of 5v into steady 5vdc....???

 

[hamid159]

yes,you can.first you will convert 220v AC into DC.and then feed it to the mosfets.which will operate at some high frequency to drive the transformer.By rectifying the secondary voltage,you can get 5v dc.note that to make regulated 5vdc,you have to feed the voltage back to pwm driver through optocoupler or may be voltage divider.

 

[kam1787]

how much current do you need?

 

[JAMAL JIMI]

About 1-3 Amps...

 

[hamid159]

if you need only 1 - 3 Amps current at 5V (max 15Watt) ,then it should not be so difficult.have you tried it?if, then what problem you are facing?

 

[kam1787]

Use a conventional circuit; transformer, full-wave rectifier, capacitor, regulator [ie boosted LM7805: https://www.eleccircuit.com/boosting-regulator-current-for-ic-78xx-by-mj2955/] or https://www.eleccircuit.com/microprocessor-dc-regulator-supply-5v-3a-by-lm323k/
or
buy a SMPS

 

[JAMAL JIMI]

No I haven't tried it yet....

 

[ALERTLINKS]

There are 5V mobile phones chargers readily available in market for less than a $. Why not use it?