2B-MAKE YOURSELF THIS LOW COST MULTIPURPOSE LIGHT WITH LOW VOLTAGE INDICATOR
This project is a multipurpose project. This can be used as an emergency light when the power is off. You can also play radio, utilizing the 12 Volt power available from the socket or utilized this power in any other electronics instrument consuming low power. This low voltage indigator indicates the battery position.
TECHNICAL DESCRIPTION & WORKING:-
This project has been developed and successfully tested in the TV Engineer Technical Lab.
This project requires a Kissan Torch. If you hava a battery torch, you can assemble this project at a very low cost. In this 12 volt emergency light unit, the 12 volt available from 12-0-12 transformer is not directly connected to the positive terminal of the battery. A protecting Diode D3 and a Capacitor C1 has been connected across the relay. The diode protects the relay. One attraction of this unit is that the red LED glows indicating low voltage after the battery is discharged to a certain specified limit.
Battery should not discharged fully. Full discharged affects the battery life.
- When the unit is connected to a live AC, the torch will not glow even if the switch is put ON.
- Put the switch OFF the unit ON when required and connect the main lead to AC. When ever there will be AC failure, the unit will automatically glow and when AC is again live, the bulb will stop glowing automatically.
- You can derive 12 Volt DC from the DC jack fitted in the unit & use the power anywhere which require 12 Volt DC & consumes low current.
- To check the unit after it is assembled, put the switch of the torch ON. It will glow. Put the main lead to live AC, the bulb will stop glowing.
PRECAUTIONS WHILE ASSEMBLING
- Check all components as per the circuit.
- Remember the anode and cathode of diode before fitting.
- Remember to check dry soldering and short circuit.
D1-D1-D3 – IN 4007 – 3
CONDENSER C1-1000 MFD/25V – 1
AC TRANSFORMER 12-0-12 – 1
RELAY – 12V 100OHMS – 1
S1 – TOGGLE SWITCH – 1
BULB – 12V – 1
DC JECK AND PIN – 1 [EACH]
DRY BATTERY 12V – 1
TR – 1, TR-2 – BC147 – 2
RESISTANCE [ALL QUARTER WATT]
R1,R3 4K7 – 2
R2-220E – 1
R4-330E – 1
R5-1K – 1
VR-1, VR-2-2K2 PRESET – 2
RED LED – 1