How to Calculate the Field Current in a DC Motor

How to Calculate the Field Current in a DC Motor
••• fotografo/iStock/GettyImages

Direct current, or DC, electrical motors convert electric energy into mechanical energy similar to AC electric motors. The mechanical energy is then used to power everyday items such as electric hairdryers, power tools, car alternators and a variety of other tools. DC motors differ from AC motors in that they are not frequency-dependent like AC motors. AC motors require 60 hertz power that's available through 120 voltage AC outlets. DC motors are powered by batteries or nonfrequency-dependent power supplies.

    Find the DC voltage rating of the power source or the battery powering the DC motor. Refer to the specification sheet of the battery or DC power supply. For small batteries, you can find the voltage rating on the outer casing of the battery. Call this value V.

    Find the field resistance or terminal resistance of the DC motor. Refer to the schematic or the specifications of the electric motor. Call this value R.

    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.

Related Articles

How Are Radical Expressions & Rational Exponents Used...
How to Calculate Potential Difference
How to Calculate the Magnetic Force of a Solenoid
How to Figure kW Rating of a 3 Phase Electric Motor
How to Calculate Millivolts to Amps
How to Calculate DC Voltage
How to Calculate Power Rating
How to Calculate Induced Armature Voltage
How to Calculate the Henrys in a Coil
How to Convert Ohms to Kilowatts
How to Calculate Peak Torque
How to Find the Volume of a Sphere in Terms of Pi
How to Calculate Toroidal Transformers
How to Calculate IRMS
How to Calculate Voltage Across a Resistor
How to Calculate Battery Voltage
How to Measure Electric Motor Torque
Test Your Knowledge on Middle School Science
How to Calculate the Short Circuit Rating

Dont Go!

We Have More Great Sciencing Articles!