Over charging is taken care and protected by t1.
Led emergency light circuit with battery overcharge protection pdf.
Before the use of this circuit you need to adjust the cut off voltage range for autocut.
Now to get started adding solar power to your small electronics projects and use the sun to power your battery powered night lights garden lights and other automated decorations or.
A 12v 7 2ah battery can be used to light up to 100 leds.
The following led emergency light with battery over charge protection feature circuit was designed by me in response to the request sent by pp.
The article describes an led emergency light circuit with advanced features such as over charge battery cut off.
One part is the led lamp light circuit and the other is the battery charger circuit.
All current ratings and voltage ratings are perfectly calculated with basic and clear instructions.
This 12v battery charger circuit with auto cut provides the automatic cut off facility when the battery get fully charged.
Since this circuit diagram does not have battery overcharging protection it is advisable to connect a 13v zener diode across battery terminals.
And second part consists of relay and rechargeable battery which is used to lighten the leds during power failure.
This adjustment is done by the 10k preset and a multimeter connected with the output terminals that goes to battery.
Automatic led emergency light with under voltage cut off protection.
The design objectives were accomplished because the lantern can successfully provide a relatively good illumination for over three hours and the battery over charge protection circuit prevents the battery from being over charged.
When the circuit is powered the voltage across base and emitter should be around 0v.
A further modified version is also available where under voltage cut off protection is provided for the led emergency light circuit.
You can find the circuit here.
With this circuit over night the battery will get charged fully.
Hope with the above guide line you can make your light work successfully.
That does not make it good but its easy and cheapish and works reasonably well.
First part is used to drop down the 220v ac voltage into 8v regulated dc with the help of transformer and bridge rectifier.
The post explains an led emergency light circuit with sophisticated capabilities such as over charge battery cut off day time auto disable and need less to say that the circuit switches on the leds instantly when ac mains goes wrong and reverts to charging mode when power is renewed.
This led emergency light circuit can be divided into two parts.
Some led drivers incorporate a voltage multiplier or voltage booster in the led driver circuit since 1 2 volts is insufficient to power the ultra bright leds.
This is manifested by the light emitting diode led which turned on when the battery is fully charged.
