Hi All,

We are doing small project on 3phase R,Y,B,phase and neutral indication circuit using lamp,
Please find the attachment of schematic.
when all the phases, neutral and Earth is present all 6leds will glow if not respective leds will glow.
The problem I'm facing here is when I interchange phase R and neutral lamp L1 should off because of diode reverse bias but here it is not happening,even for reverse supply lamp is glowing

 

Remember you are dealing with AC.
Max.

 

Remember you are dealing with AC.
Max.

Hi Max,

Please Suggest suitable way to solve the problem

 

Hi Max,

Please Suggest suitable way to solve the problem

Are you trying to detect loss of phases, or Neutral and Phase reversal?

Your diodes just half the voltage across the lamps.

 

With the above circuit i'm measuring AC health condition ,this should indicates 3 phases ,Neutral and also Earth condition(present or not present)

 

Just use three neons across each Phase to Neutral or Earth with 220K resistors.

If you want to go across each Phase to Phase, then use 470K to 1M resistors.