wheatstone bridge

[kavhra]

I have an AC voltage source with 4 capacitors I deliver 11.31RMS Volts to a wheatstone bridge with 4 capacitors the bridge is symmetrical but the output is not zero.
Please help
Thanks

 

[KlausST]

Hi,

schematic, test conditions, part values ???

Klaus

 

[D.A.(Tony)Stewart]

What do you expect with mismatch tolerances?
Do you have a better question? What is your intention? to verify school theory?

 

[barry]

It's broken. Buy a new one.

 

[BradtheRad]

Capacitors have a way of introducing phase changes. (Same for inductors.) It means waveforms don't align, making it difficult to obtain identical readings in the middle of your Wheatstone bridge.

Only if you can adjust Farad values so that lefthand time constants match righthand time constants, will you align phases.

 

[ZappHappy]

Yes Kavhra, Brad is correct, AC bridges can be tricky to balance without additional adjustments for DC leakage and other (non-ideal) capacitor characteristics.. You can always replace the cap's with equal resistors to prove your bridge is working.. Also, if you are working at 50/60 Hz you may not ever see a null due to local pickup of power line "noise" try raising the frequency if this is the case...

 

[D.A.(Tony)Stewart]

I have an AC voltage source with 4 capacitors I deliver 11.31RMS Volts to a wheatstone bridge with 4 capacitors the bridge is symmetrical but the output is not zero.
Please help
Thanks

say more. What are the tolerances and your result?