How to Regulate DC Power With Resistors

By David Sandoval
Resistors can be used to regulate voltage and current in a DC circuit.

Resistors are electrical devices that restrict the flow of electrical current through a circuit. Resistors can be used for several functions, such as voltage isolation or setting a limit for how much current flows through the circuit. Using resistors for either function allows the power of the circuit to be regulated.



Cut two pieces of electrical wire and strip 1/2 inch of insulation from the ends of each wire segment.

Twist one of the leads from one of the resistors together with one end of the first wire. Attach the loose end of the first wire to the positive battery terminal. Note that you only need one resistor for this circuit.

Attach one end of the second wire to the negative battery terminal.

Turn on the digital multimeter and set the measurement scale to “DC Amps.” Place the black probe on the loose end of the first wire. Place the red probe on the unoccupied resistor lead. Read the multimeter display; the electrical current flowing through the circuit will be about six milliamps. By adding one kiloohm of resistance to the circuit, the resistor has limited the circuit current to six milliamps.

About the Author

David Sandoval has served as a trainer and technical writer since 2000. He has written several articles online in the fields of home improvement, finance, electronics and science. Sandoval has an Associate of Applied Science in microelectronics from Northern New Mexico College.