Okay so recently i have been wanting to make my own solar charge controller, I had a look round at circuits, They had regulators, dedicated IC's (555 timers, opamps ect) , More expensive p channel mosfets. Basically i wanted something cheap and easy to make, I like stuff that can be made by people on a real budget but that isnt complete garbage (Air quotations).
I decided on using the internals of the lm339 as its a pretty robust comparator.
Basically , My know how is basic at best. So if anything in the circuit pops out to be wrong, please feel free to berate me on it or if you have any recommendations on changes i could try that would be appreciated . Also it means i can make sure i am ordering everything i need.
My 2 main concerns.
1) im using a 12v relay, the panel voltage does go up to 17v, would i need additional protection , i did try simulating a totem driver as it half's the voltage and i thought having a 6v zener regulator with a 6v relay but i wasn't 100% happy with the circuit.
2) my resistor values, I did try and work some out but wasnt sure on some things, like swapping out the resistors for where the diodes should be.
The batteries on the left, solar cell on the right, LED is just there to show the state of the relay.
I decided on using the internals of the lm339 as its a pretty robust comparator.
Basically , My know how is basic at best. So if anything in the circuit pops out to be wrong, please feel free to berate me on it or if you have any recommendations on changes i could try that would be appreciated . Also it means i can make sure i am ordering everything i need.
My 2 main concerns.
1) im using a 12v relay, the panel voltage does go up to 17v, would i need additional protection , i did try simulating a totem driver as it half's the voltage and i thought having a 6v zener regulator with a 6v relay but i wasn't 100% happy with the circuit.
2) my resistor values, I did try and work some out but wasnt sure on some things, like swapping out the resistors for where the diodes should be.
The batteries on the left, solar cell on the right, LED is just there to show the state of the relay.