Hello everyone, I'm new here. First I'd like to commend all of you for the amazing work you are doing. I've seen some circuits on my project but not one with all I need. I want to design an automatic emergency light with the following features ;
-transformerless power supply
-makes use of LDR to stop bulb from shining during the daytime
-has battery overcharge protection and cuts of supply when there is prolonged power outage to prevent damage to battery
-has red indicator for charging, green indicator for full charge and orange indicator for low battery
Aswinth Raj
PermalinkHi Ugwu,
Lets see how we can build it. I cant give you a complete circuit diagram but sure can give you some insights.
I think you are trying to keep thins compact by avoiding a transformer. In that case you should have to design your own SMPS which can source +5V and 1A. There are also modules available online you can check on them if intrested.
Since you are asking for protection, it should be a Lithium battery I guess. You can use a normal 18650 Lithium cell based on the current rating of your battery. You can use the TP4056 module which can charge your Li+ from your Charger module and als protect it from over charge and discharger. This module will also give you the indication lights that you fish for.
Okay, you have to use Op-Amps for this. Compare the variable voltage from the LDR and compare it with a Preset voltage and trigger the LED based on it. You can also use the indication LED's the same way
Hope it helps!! All the best!!
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Joined August 16, 2016 1000Tuesday at 12:29 AM