projects.borg.ch/electronics/batterylight/
This project is an automatic light which switches on during a power outage
if it is dark outside and charges the lead batteries when we have power.
Version 1.0
Features:
- LDR mounted on a window to measure the sunlight.
- Under voltage switch off adjustable between about 10V and 11.5V.
Depends on the voltage of the LED, my green one has about 1.9V.
- External power supply limited to 14.1V and 1A.
Obviously this has to be replaced in a later version.
Bugs:
- The big capacitor in the power supply leads to an about 10 seconds
delay until the light switches on.
- Spikes on the AC input (a few half aves) make the light go out.
- Sometimes the light flickers during the day. I think this happens
when some spikes are induced into the LDR wires.
Version 2.0
Features:
- LDR mounted on a window to measure the sunlight.
- Delayed switch on and off to prevent blinking.
- Under voltage switch off adjustable between about 10V and 11.5V.
Depends on the voltage of the LED, my green one has about 1.9V.
- SEPIC battery charger.
Power vomes from the external 12V power supply
which is also used also for the water pump.
Bugs:
- The big capacitor in the power supply leads to an about 10 seconds
delay until the light switches on.
- This rubbish aluminum wire has a hig resistance and loses too much voltage.
Have to adjust the voltage divider R14/15.
- When the battery is full the SEPIC switches to discontinuous mode.
It then runs 5 second, then makes 5 seconds break, and so on.
Version 2.0a
Adjusted the R14/15 voltage divider and updated the schema.
Everything else is the same as with V2.0.
Now it works even with the high resistance rubbish wire.
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