Home >> Science & Nature >> Science

How to Build a 12 Volt Voltage Reducer

To build a 12-volt voltage reducer, use a linear IC regulator, which is a semiconductor that can provide stable voltage and current outputs. When used with a heat sink, it can handle load currents up to 1.5 amps. Linear ICs have three pins; the input, output and ground. The input must have a voltage two to three volts larger than the size of the desired output voltage. Linear ICs typically require a capacitor on their input and output to control ripple or noise. Practice with an LM7805, which can reduce 12 volts to approximately 5 volts.

Things You'll Need

LM7805
0.1 uF ceramic disc capacitor
0.22 uF capacitor
1-volt battery or power supply
Breadboard
Jumper wire
Digital multimeter

Instructions

- 1
  Choose one row on the breadboard that is ground or zero voltage. Choose another one as the positive voltage source. Insert the LM7805 chip horizontally so that all three pins fall into different columns. Typically, the pin on the left is the input or pin 1, the middle is ground or pin 3 and the output is pin 2 on the right.
- 2
  Attach one end of a jumper wire to pin 1. Place its other end in the positive voltage row. Add one end of the 0.22uF capacitor to the column at pin 1 as well. Add its other end to ground.
- 3
  Connect one end of the 0.1 uF capacitor to pin 2. Connect its other end to ground.
  
  Wire pin 3 directly to ground.
- 4
  Connect the positive voltage side of the power source to the positive row. Connect its negative side to the ground. Turn the power on.
- 5
  Measure the output voltage at pin 2. Turn the multimeter to a DC voltage setting. Place its red lead on the left side of the output capacitor, and the black lead on the capacitor's right side. An example reading is 4.96 volts.

Science