Emergency Light.

Source: http://www.josepino.com/?emergency_light   Tags: electronics circuits light homemade

I built this circuit about 12 years ago because the workplace where I was working didn't have windows. When the power was out, for a few minutes the entire office was completely dark. As some lead-acid rechargeable batteries were available, I decided to build this circuit.

I remember that I used some recycled parts, also a tranformerless power supply. This circuit should be completely covered by a plastic container with the appropiate ventilation. Here is the schematic:
Taken from http://www.josepino.com

A small sealed maintenance-free battery is perfect, it can provide up to 4 hours of light. If you want someting smaller and easy to install, you can replace the battery and lightbulb with a super bright white led (12,000 mcd at least) and a 1F supercapacitor. Here is the circuit:

When the circuit receives power, it acts like a trickle charger for the lead-acid battery. When the power fails, the relay is off and it sends the battery power to the lightbulb.

I'm not sure if this circuit can work with ni-cad batteries, but I think it may work without modifications. The zener diode must be 13V for the battery-version and 5 volts for the LED version.

08/13/09 - 08:35:31 JJ from Belgium wrote: Hi,
I like the circuit,
But i have a few questions, can you give me an e-mail adress to send them to?
Thanks and keep it up!
08/13/09 - 11:03:18 JJ from Belgium wrote: Nevermind ;) I found the problem.
Thanks for the schematic (for the charger)!
08/28/09 - 05:07:12 Z from KR wrote: This is a very simple and very useful circuit. I think so. If I put it (AC) to 220volt 60Hz then what will be changed or need?
08/28/09 - 05:15:50 José Pino wrote: Sorry Z, I can't give advice about 250VAC circuits.  That voltage is dangerous and I do NOT have the experience with it, so I can't tell what to change.
09/10/09 - 14:05:01 uday from india wrote: im uday,thanks for the ckt, but is the ckt same for 220v AC?
10/12/09 - 02:00:13 Key from NZ wrote: Hi man, I like your circuit design but could you tell me, which bridge are you used? coz i got 4 to 5 design for diffrent voltages. and I dont want to confuse myself.
another important thing is that i never come across with SUPER CAPACITOR, how does it work n how long it runs LED? can i have your email address plz.

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