A 19th century engineer named Gustav Robert Kirchhoff explained the relationship between voltage and resistance in a circuit. Kirchhoff’s Voltage Law explains that within an electrical circuit, the sum of the voltages around the closed loop of the circuit is zero.
In a direct current circuit, the electrical current through the circuit flows in one direction, and is of the same amperage throughout the circuit. Therefore, as the electrical current flows through the circuit, the voltage will differ depending upon where voltage is measured within that circuit.
To divide the voltage coming from a DC power supply (such as converting from 12 Volts to 6 Volts) and still comply with Kirchhoff’s Voltage Law, you would have to construct a voltage divider within the circuit. This can be done using two resistors of equal resistive value.
Using the electrical pliers, twist one of the leads from the first resistor together with one of the leads from the second resistor.
Attach the free lead from the first resistor to the positive terminal on the power supply. Attach the free lead from the second resistor to the negative terminal on the power supply.
Turn on the power supply. Turn on the digital multimeter, and set the measurement scale to “Volts DC.”
Attach the black (negative) multimeter probe to the negative terminal on the power supply. Attach the red (positive) multimeter probe to the electrical joint between the resistors. Read the multimeter display; the voltage differential will be 6V DC.