Good morning,
I am a student in electronics & would like to ask about my solar lamp design which is far from perfect.
I want to use a 6V solar panel to charge a lipo through the TP4056 charging board. On the side I would like to do a night detection circuit to activate my solar lamp when the sun is down enough.
I have first tried to build it with 2 NPNs as described in the attachement LT spice simu with the name " solar led driver NPN". The design seems to work but I am not really in total control of what is going on there. I would like to understand how to tune my circuit resistors & values in order to for example switch it on when the solar panel voltage drops lower than X Volts. Could someone enlight me onmy mistakes & which parameters to tune there please?
I then found someone on the internet telling to use a PNP which seems to give me a much better result, even tho I am really having a hard time understanding how that circuit works. I have again no control over the system & would like to understand it & be able to tune the parameters in a comprehensive way.
thank you for your time & consideration.
Best Regards;
Gwen
In blue I plotted the solar panel discharge voltage; In green the current flowing through the LED.
I am a student in electronics & would like to ask about my solar lamp design which is far from perfect.
I want to use a 6V solar panel to charge a lipo through the TP4056 charging board. On the side I would like to do a night detection circuit to activate my solar lamp when the sun is down enough.
I have first tried to build it with 2 NPNs as described in the attachement LT spice simu with the name " solar led driver NPN". The design seems to work but I am not really in total control of what is going on there. I would like to understand how to tune my circuit resistors & values in order to for example switch it on when the solar panel voltage drops lower than X Volts. Could someone enlight me onmy mistakes & which parameters to tune there please?
I then found someone on the internet telling to use a PNP which seems to give me a much better result, even tho I am really having a hard time understanding how that circuit works. I have again no control over the system & would like to understand it & be able to tune the parameters in a comprehensive way.
thank you for your time & consideration.
Best Regards;
Gwen
In blue I plotted the solar panel discharge voltage; In green the current flowing through the LED.