Hi

Just wondering if it is somehow possible to measure DC voltage on a cheap panel AC voltmeter?
I just need a rough measurement to indicate the presence of 200VDC at the output of an DC-DC inverter. I thought of using an NE-2 type neon bulb but, that would light up even at 75V. Any other idea would be welcome.

 

Analog meters are generally DC meters. If you know the full scale range of the AC meter, build a voltage divider using two resistors to reduce the DC voltage to suit the range of the AC meter. Calibrate against another DC meter or known voltage source.

 

Analog meters are generally DC meters. If you know the full scale range of the AC meter, build a voltage divider using two resistors to reduce the DC voltage to suit the range of the AC meter. Calibrate against another DC meter or known voltage source.

The meter what I am considering is a mini sized AC panel meter with maximum scale 300VAC. I don't think a voltage divider would be needed because, 200V falls within 300V range. So, the conclusion is a cheap AC panel voltmeter can be used as DC voltmeter without any modification.......Right?

 

No. I think MrChips has in mind a basic analog voltmeter intended to be used as a test instrument, not a specialized panel meter that is intended to be used for one specific type of measurement. Unless you can tear into the meter and remove the filter, I don't see an obvious way to do it.

If you are in a position to consider which meter you will use, why not just get a suitable DCV panel meter?

 

No. I think MrChips has in mind a basic analog voltmeter intended to be used as a test instrument, not a specialized panel meter that is intended to be used for one specific type of measurement. Unless you can tear into the meter and remove the filter, I don't see an obvious way to do it.

If you are in a position to consider which meter you will use, why not just get a suitable DCV panel meter?

DC panel voltmeters are comparatively quite expensive.

I am thinking to use this type

 

If the meter has a series capacitor to block DC then it won't measure DC, but just try it and see if it works.

 

That looks like it might be a moving iron type meter, not a moving coil type, considering the non linear scale.
In which case it would be OK on DC.

 

If you read this All About Circuits paper it will explain what many of the posters are relating to as to meter types. The trick becomes knowing what you have as in which type of meter movement.

Ron