Description.
Here is the circuit diagram of a battery
eliminator circuit that can be used as a replacement for 9V PP3
batteries. The circuit given here can be used to power any device that
operates from a 9V battery. The transformer T1 steps down the mains
voltage and bridge D1 performs the job of rectification. Capacitor C1 is
a filter. IC LM317T is the regulator here. The value of R1, R2 and R3
are so selected that the output voltage of IC1 will be steady 9 volts.
Circuit diagram.
- Assemble the circuit on a good quality PCB.
- Transformer T1 can be a 230V primary, 9V secondary, 1.5A step down transformer.
- If 1A Bridge is not available, then make one using four 1N 4007 diodes.
- Do not connect loads that consume more than 1.5A to this circuit.
- A heat sink is recommended for IC1.