How to Test Rectifiers

A voltage rectifier is a device that turns AC voltage, which swings from positive to negative and back again continuously, to DC voltage, which remains at a steady level. Many power supplies, such as standard electrical outlets, produce AC voltage. Many handheld tools and other devices use DC. You can easily test a rectifier using common electrical equipment.

• 1

  Select a resistor at random. Divide your AC voltage by this resistance. The result is the current that will flow into this resistor when it's hooked up to this voltage.

• 2

  Multiply that current by the voltage of your AC source. This is the power produced when that resistor is hooked up to that voltage.

• 3

  Compare that power to the power rating of your resistor. If it is larger, select a larger resistor and recalculate. Add together smaller resistors to get larger resistances.

• 4

  Snap the resistor into the breadboard. If you need more than one resistor, snap them in sequentially, one next to the other. Some of the holes in a breadboard are connected to each other by thin strips of metal underneath. Put one end of one resistor in one of these holes, and one end of the next resistor into the hole it is connected to. This connects the resistors as one.

• 5

  Remove 1 inch of insulation from each end of the two short wires with the strippers. Snap one end of each wire into the breadboard so that one wire is connected to each end of your resistors.

• 6

  Touch your power source to the wires that are attached to the resistors. Because resistors can accept current flowing in either direction, they can handle the unrectified AC voltage without harm.

• 7

  Set the multimeter to AC voltage. Read the voltage across your resistors. Record this number. Set the multimeter to AC current. Read the current flowing through your resistors. Record this number. Remove the power source from the wires.

• 8

  Multiply the current in amps by the voltage in volts. This tells you how many watts of AC electrical power flows through such a resistance from your power source.

• 9

  Hook up your voltage rectifier to your power source. Touch its output to the wires that are attached to the resistors. DC voltage is applied to them.

• 10

  Set the multimeter to DC voltage. Read the voltage across your resistors and record the number. Reset the multimeter to DC current, and read the current in your resistors. Record this number.

• 11

  Multiply the DC voltage in volts by the DC current in amps. This tells you the power in watts flowing through your resistors from the rectifier. If the power is the same in both cases, your rectifier is functioning properly, transforming all the AC voltage into DC voltage.