This Variable Power Supply allows you to change voltage depending on your requirement.You can change the voltage from 1.2 Volts to 13.4 Volts. So you can use this variable power supply for powering your projects too.
This variable power supply consists of IC LM317T which allows you to vary voltage.
Step 1: Circuits Used in Variable Power Supply
Variable Power Supply Consists of following circuits
- Full Wave Rectifier
- 15 Volt Regulator
- Adjustable Voltage Regulator.
Step 2: Components Required
Components for 15 Volt Regulator
- 12-0-12 V Transformer
- Gendral Purpose PCB
- 1N5408 Diode---------2
- 2200uf,50V capacitor
- Heat Sink
- IC 7815
Components for Adjustable Voltage Regulator
- Gendral Purpose PCB
- 1N4007 Diodes
- IC LM317T
- 10uf,50V capacitor
- 560 ohm Resistor
- 0.1uf ceramic capacitor
- 5K pot
Step 3: Schematic Diagram of Variable Power Supply
I had also attached Schematic File Below
Step 4: Assembling Variable Power Supply
I had soldered the components in Gendral Purpose PCB according to schematic diagram of variable power supply.
Step 5: Schematic Diagram of 15 Volt Regulator
Step 6: Operation of 15 Volt Regulator
The 15V Regulator Use 12-0-12 Volt transofrmer.The 12 volt at input of 15V regulator circuit is amplified into 16V by the use of 2200uf capacitor.The capacitor is connected at the output of Full Wave Rectifier.The full wave rectifier is formed by two diodes 1N5408.The full wave rectifier will convert 12V AC into 12V DC.The Voltage at the output of full wave rectifier is 12V.If we add 2200uf capacitor at the output of full wave rectifier in parallel.The 12V is boosted into 16V. This 16 V is given to IC 7815.This IC will regulate 16V into 15V. So you get 15V at the output of 15 Volt Regultor Circuit.
Step 7: Assembling 15V Regulator
I had soldered Components in Gendral Purpose PCB according to schematic diagram of 15Volt Regulator.
Step 8: Schematic Diagram of Adjustable Voltage Regulator.
Step 9: Operation of Adjustable Voltage Regulator
The adjustable voltage regulator consists of IC LM317T which is designed with resistors to control voltage from 1.2V to 13.4V.We know that PN junction diodes conduct only in forward direction.The two diodes 1N4007 which is used for protection purpose.The 5K Potentiometer is used to vary voltage.The pot is to be fixed with knob for adjusting voltage comfortably.
Step 10: Assembling Adjustable Voltage Regulator
I had soldered the components in gendral purpose PCB according to the schematic Diagram of Adjustable Voltage Regulator.