I've hear dof this but never seen such a marked example.
I have a big old industrial edge wise meter, the scale is about 8 by 2 inches, the needle is also about 8 inch long, and its sensitive at 50uA.
To try and get it not to wander around with the slightest fluctuation in voltage I've put a 22r resistor as a shunt across the coil to make it a 1mA meter.
Now the movement is real slow, 30 secs for sull scale, presumably this is back emf and 'dynamo' effect, the 22r resistor is so low that back emf across the coil resists deflection and slows it down, and the meter movement generates a small amount of energy under the return spring that fsd to no deflection is also slowed.
Or is something else happening here.
The meter is going to show minutes in a steampunk clock project so its actually ok.
I have a big old industrial edge wise meter, the scale is about 8 by 2 inches, the needle is also about 8 inch long, and its sensitive at 50uA.
To try and get it not to wander around with the slightest fluctuation in voltage I've put a 22r resistor as a shunt across the coil to make it a 1mA meter.
Now the movement is real slow, 30 secs for sull scale, presumably this is back emf and 'dynamo' effect, the 22r resistor is so low that back emf across the coil resists deflection and slows it down, and the meter movement generates a small amount of energy under the return spring that fsd to no deflection is also slowed.
Or is something else happening here.
The meter is going to show minutes in a steampunk clock project so its actually ok.