In the electrical trade it is called control voltage. This voltage can be any voltage. In North America the common control voltage is 120 volts.
With voltage control there is so much voltage drop due to resistor, that's the disadvantage
The difference between a current control device and voltage controlled device is that for current controlled device, the current is constant and the voltage is variable while for a voltage controlled device, the voltage is constant and the current is variable.
A control transformer marked 240V - 24Vac would have a control voltage of 24 volts.
== == voltage in the windings does NOT control the speed of a motor, but the armature voltage does. on DC motors speed can controlled by varying the resistance of the field winding or the armature voltage
A: A RESISTOR is a passive component it cannot control voltage these components and/or current it can however limit
Voltage stabilisers are the devices to control voltage. These are of 3 types i.e. VARIAC BASED,IGBT BASED and THERMISTOR TYPE. These are classified according to voltage correction speed i.e. from 70 volt/second to 750 volt/seconds.
Advantages in electric circuits : Advantages of using the rheostat in electric circuits is optional as you could just use the dial on the power-supply to vary the voltage (p.d.), and therefore the current. The advantage of using the rheostat is that you can control it to give you nice even numbers for the voltage.
Between power and control voltage circuits
The engine control module acts as the voltage regulator.
Aircraft alternators have an electronic voltage regulator.