voltmeter is now out of phase with the voltage
In an actual capacitive-type fuel gauge, the
input to a two-stage amplifier takes the place of
the voltmeter. It amplifies the signal resulting
from an imbalance in the bridge circuit. The
output of the amplifier energizes a winding of the
two-phase indicator motor. The other motor
winding is the line phase winding. It receives
constant power from the same voltage that powers
a series capacitor shifts its phase by 90 degrees.
As a result, the indicator motor is phase sensitive.
This means that the indicator motor will operate
in either direction, depending on whether the tank
to maintain the bridge circuit in a balanced
condition. This prevents the indicator motor from