LM317 Adjustable Power Supply Battery Charger Circuit

 Adjustable Power Supply Battery Charger Circuit

An Adjustable Power Supply is an essential tool for anyone who tinkers with electronics. It’s a device that allows you to adjust the output voltage and current according to your needs. In this DIY guide, we will be building an Adjustable Power Supply DIY with the help of two 2n3055 transistors, one LM317 Regulator IC, one BD139 transistor, and few other components.

Circuit

Adjustable Power Supply Battery Charger Circuit with LM317 and 2N3055 transistor

Before assembling the circuit, it’s important to understand the circuit diagram. The Adjustable Power Supply circuit consists of four main sections – The Transformer, Rectifier, Regulator, and Output. The transformer converts the 220V AC voltage to 30V AC. The rectifier converts the AC voltage to DC, which is then filtered using the electrolytic capacitors. The regulator (LM317) regulates the output voltage, and the output section delivers the output to the load. The circuit diagram for the Adjustable Power Supply is as shown above.

Components List

• 2N3055 Transistor x 2
• LM317 Regulator IC x 1
• BD139 Transistor x 1
• 7805 Regulator IC x 1
• 0.1uf (104J) Capacitor x 3
• 0.33 Ohms / 5 Watts Resister x 2
• 1k Resister x 1
• 220 Ohms Resister x 1
• 10k Potentiometer x 1 with knob
• 5k Potentiometer x 1 with knob
• 0-30 Volts Digital Volt Meter x 1
• 12 Volts On/Off Switch x 1
• LED x 1
• 4mm Banana Connector Socket x 1 Pair
• 12v-0v-12v Transformer
• 6-10A Bridge Rectifier
• 6800uf / 50v Capacitor
• 104J / 0.01uf Capacitor