230vac convert to 3.3V with positve clamper

[naga-k]

hi,

i want to convert 230v ac main to 3.3v with positive voltage clamping. this converted voltage used to calculate the power factor and measure the ac main voltage using microcontroller. if you any circuits please help to me.

thanks,

 

[shaiko]

you may find this discussion helpful.
https://www.edaboard.com/threads/320340/#post1369746

 

[naga-k]

you may find this discussion helpful.
https://www.edaboard.com/threads/320340/#post1369746

thanks for your reply,

i designed this circuit. pls let me know, is this correct for voltage clamper with voltage divider.



https://obrazki.elektroda.pl/2928213900_1408360619.png

 

[Disha Karnataki]

you see it is a full wave bridge rectifier after the diode which is placed in parallel with the supply voltage & capacitor in series.
two diodes are actually extra they are not required in the circuit that is:
during negative half cycle current only flows through diode & 2.2uf capacitor. Hence the bridge rectifier can be just reduced to a half wave rectifier circuit.
There is much safer way to do this that is first step down the voltage and then you may clamp:
the link below is just to step down the volatge: https://www.google.com.pk/imgres?im...ct=rc&uact=3&dur=1064&page=5&start=80&ndsp=19
And the resistances value that you will be connecting check they are suited for your application i.e by using power dissipation formula=i*2*r.
And the capacitor 2.2uf should not be electrolytic and should withstand voltage upto >=220v(supply voltage). And yes even include fuse.

 

[naga-k]

thanks for your reply,

here, we need pure sin wave for my application. so, your suggested link is not suitable for us. i have another one doubt if i connect phase neutral connection inversely what will happen in my circuit.

 

[Disha Karnataki]

thanks for your reply,

here, we need pure sin wave for my application. so, your suggested link is not suitable for us.

infact even your circuit does not gives a pure sinewave that is what i have explained in post #4 it will only give you a half wave clamped one.

i have another one doubt if i connect phase neutral connection inversely what will happen in my circuit.

what may happen!! what do u think..
well, nothing as told in post#4 that only happens.
yes, if you reverse the diode which is parallel then exactly opposite action takes place that is only negative half cycle will flow through your circuit.