- #31
vk6kro
Science Advisor
- 4,079
- 41
The first thing that would probably happen with a meter is that you bend the needle. You can straighten a needle but it never looks as good after that. :)
Then, depending on the current, you might burn out the moving coil or one of the spiral springs.
If the meter has shunts, these will burn out too, with lots of smoke. (Shunts are resistors in parallel with the meter movement to increase the current capability of the meter).
It is actually not a bad idea to put two Silicon diodes across the meter so they face in opposite directions. This stops the voltage across the meter rising above about 0.6 volts but doesn't affect the accuracy of the meter at low currents.
You would still need a series resistor even if you included diodes.
Moving coil meters are very expensive and worth looking after.
Then, depending on the current, you might burn out the moving coil or one of the spiral springs.
If the meter has shunts, these will burn out too, with lots of smoke. (Shunts are resistors in parallel with the meter movement to increase the current capability of the meter).
It is actually not a bad idea to put two Silicon diodes across the meter so they face in opposite directions. This stops the voltage across the meter rising above about 0.6 volts but doesn't affect the accuracy of the meter at low currents.
You would still need a series resistor even if you included diodes.
Moving coil meters are very expensive and worth looking after.