Introduction
The circuit of automatic bicycle dynamo headlight and battery charger is an automatic circuit. The circuit switches off the Light Emitting Diode (LED) during the daytime and connects the dynamo automatically with the circuit charger. Therefore the circuit charges the 6V 4.5AH battery during the ride of the bicycle stores a good quantity of power and this power is used for powering and charging several devices.
The circuit disconnects the battery automatically after the completion of charging and then it switches on the output LED which demonstrates that the battery the charged completely. It is because of the automatic working of the circuit that the battery works for a longer duration and is not overcharged. The circuit switches the dynamo automatically to the 12 volts 6 watts LED.
Hardware Required
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Diodes | 1N5822, 1N4148, PC817 | 4,3,1 |
| 2. | Bicycle Dynamo | 12V 6W | 1 |
| 3. | Capacitor | 2200uF,4.7uF,100nF | 1,1,1 |
| 4. | Light Dependent Resistor (LDR) | – | 1 |
| 5. | Variable Resistor | 50K | 1 |
| 6. | Resistors | 1k,4.7K,8.2k | 1,1,1 |
| 7. | LED 1 with heat sink | 12V 6W | 1 |
| 8. | Transistor | BD139, BDI40, 2N3906 | 1,1,1 |
| 9. | Potentiometer | 100K | 1 |
| 10. | Battery | 6V 4.5 AH | 1 |
| 11. | IC | LM2940T, NE555 | 1,1 |
| 12. | Zener Diode | 3.3 volts | 1 |
| 13. | Relay | – | 1 |
Circuit Diagram
Working Explanation
Initially, a DC power supply of 12 volts is connected to the circuit instead of a dynamo supply and bridge diode. The LDR is enclosed with a black solution tape and the resistor of 50K is adjusted until the LED of 6W is switched on. Then 6V 4.5AH battery is detached from the circuit and instead of it a variable power supply of 7.3 volts is connected to the circuit. A variable resistor of 100K is adjusted until the second LED goes on. Then black solution tape and 6V 4.5AH are detached from the circuit and the bicycle dynamo with bridge diode of four 1N5822 diodes is connected with the circuit. The circuit delivers the best output in an appropriate enclosure.
Application and Uses
The circuit of the automatic bicycle dynamo headlight and battery charger is used for powering and charging several devices.
