Introduction: Voltage Controlled Switch

 This is a little circuit that i designed that could be used for a charging controller or voltage limiter. Its very useful if you are thinking of making a solar charger. 

Step 1: Get the Stuff

To build this circuit you would need the following:
2 1k ohm resistors 
2 5V zener diodes
A comparator (the one it used is a KA393)
A led
A Project Board / Breadboard
A Digital Multimeter
A variable power supply ( of your choice once its in the limits of the comparator)
Some wire

Step 2: Assemble the Circiut

 In the assembly of the circuit u can alter the circuit as you please. For instance i didn't go as exact as the schematic.
Just follow the diagram below.
Just in case you don't know how the comparator works heres a link that shows how.
home.cogeco.ca/~rpaisley4/Comparators.html

Step 3: What Its Suppose to Do

 In the circuit that i build thats not totally the same as the in the diagram, is suppose to turn on the led at 8V because i used a 5v and 3v zener. I also used a two 9 V batteries which voltages differ. The circuit i suppose to turn the led on at 8 V and any voltage lower than it should go off. 

Step 4: Tips

 If turn the comparator positive and negative leads around will have the reverse effect. I mean instead of  turning on at 8V it will turn off and any voltage thats lower than that it will be on. Sorry i don't have a picture of that particular instance, but i will put in one any way. [ for decorative purposes]
Also to increase the current of a load which it quite large the LED can be replaced with a P-MOSFET which will give you the gain.

Step 5: Thanks

 Thanks for looking at this and i hope that it was helpful .Have a good and GODLY day.