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Thus, the speed of a DC motor can control in three ways: By varying the flux, and by varying the current through field winding. By varying the armature voltage, and the armature resistance. Through the supply voltage.

## Are DC motors controlled by voltage or current?

The speed of Dc motors is controlled by **the current and voltage** applied to the windings or armature coils. Adjusting the current flowing into the field coils will also dictate the speed of the device. Therefore, DC motors feature a proportional speed-current relationship.

## How do you slow down an electric motor?

If you want to reduce rpm without compromising speed regulation then use **a voltage regulator or PWM controller to lower the motor** voltage. If you also want higher torque then use a gearbox (which increases torque by the same proportion as it reduces shaft rpm).

## How many volts can a DC motor generate?

Typical DC motors may operate on as few as **1.5 Volts or up to 100 Volts or more**. Roboticists often use motors that operate on 6, 12, or 24 volts because most robots are battery powered, and batteries are typically available with these values.

## How do you calculate the power of a 12v DC motor?

If the DC motor is 12 v and has 3 amps, then is 36watts and a 12 volt battery on 75 amps/h will give you 12*75=**900watts**/36 = 25 hours.

## Is RPM proportional to voltage?

Voltage is set by the supply. When spinning the motor generates an internal voltage called **back-emf**, which is proportional to rpm. The difference between the back-emf voltage and the supply voltage is dropped across the motor’s internal resistance (Rm), resulting in a current draw according to Ohm’s Law (I = V/R).

## How do you calculate current in a DC motor?

Calculate the field current for the motor using the formula **I = V/R where** I is the field current. As an example, assume V is 40 volts and R is 500 ohms: I = 40/500 = 0.08 amps.