While constructing circuits on Bread board, sometimes we need a well regulated power supply. For this, we use Voltage Regulator IC. But, its needs some components and take some space in the bread board. For an easy project making, we can make a Permanent Regulated power supply board that can be hooked in the bread board. The power supply board has a 3 pin socket, so any Voltage regulator of the 78XX series can be connected in it. The power supply board has noise and transient filtering capacitors, a buffer capacitor and input and output indicators. So by plugging the power supply board in the bread board, we save time and save much space in the bread board for the circuit assembly. Easy project building makes the circuit perfect.
You need the following components
3 pin connector with wire – 1
IC 78xx series like 7805 or 7812 – 1
0.1 Capacitors – 2
100 uF 25V Electrolytic capacitor – 1
3 mm Red LED – 1
3mm Green LED – 1
Hook up wire- 2 colour
IC 78XX series ICs are Positive voltage regulators that give well regulated output voltage. For example, 7805 gives 5V output. But sometimes, the Voltage regulator IC drops 0.1 V due to its internal drop. We can ignore that slight voltage drop because; the output will not rise above its rated voltage. 78XX series are 3 pin devices. First pin is In, second pin is Ground and the third pin is output. The capacitors on either side of the Voltage regulator, removes transients and noise from the power supply. IC 78XX series requires minimum 2 volt excess at the input than its rated value. For example, we have to give minimum 7V as input for 7805. Then only the IC gives exact 5V output.
Construct the circuit on the Perf board as per the circuit given below.
Input wire should go to the input power supply such as Battery or Adapter. Ground wire is common for input and output. Output wire should be hooked in the positive track of the Bread board.
The same Socket can be used to as Tester to check the Voltage regulator. If both LEDs are lighting, the Voltage regulator is good. If Green LED remains off, the regulator is a bad one and giving no output.
For more info of Voltage regulator IC, See links