Light Sensing Switch for Solar Project

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tmcleod
 
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Light Sensing Switch for Solar Project

Post by tmcleod »

tl;dr - I'm looking for a 5v light detection switch.

Hey all!
So I've successfully got the Lithium Ion/Polymer charger + PowerBoost 1000 running as a charger and power source for a USB 5V project. I need the project to run during the day and turn off in the evenings with the battery functionally just working as a bit of backup and buffer.

What I'm looking for is a light detection relay/switch that can sit between the Charger and Powerboost to cut the load when the light goes away (aka night time!). Do you have any thoughts on what products I can use to create this. Thanks! - Tom

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zener
 
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Re: Light Sensing Switch for Solar Project

Post by zener »

Well, you are in luck since you have a light sensor right there in the form the solar panel. You could put a 5V coil relay across the input to the charger. It will turn off when the voltage from the panel goes below around 3V (depends on the relay), which will occur when it gets dark.

Here is one you might be able to find locally:

http://www.radioshack.com/product/index ... PerPage=60

There are other ways to do it of course, if you don't like that one.

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tmcleod
 
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Re: Light Sensing Switch for Solar Project

Post by tmcleod »

This would almost work perfectly... the problem is the Adafruit Solar Charger board automatically switches to the battery when the load drops below. The main thing I want is for it to not run the battery down during the night when it's no longer needed... So basically the sensor needs to sit between the LOAD(Powerboost) and the Charger board, to drop the load to 0 at night. Thanks! - TM

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zener
 
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Re: Light Sensing Switch for Solar Project

Post by zener »

A relay has two separate parts: the coil and the contacts. You can attach the coil one place in the circuit and put the contacts another place.

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tmcleod
 
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Re: Light Sensing Switch for Solar Project

Post by tmcleod »

Yessssss. That makes sense for sure. Great call. Thanks!!

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