Hi,

I've put together a circuit with some ready-made PCBs. A PV solar panel charges a Li-Po battery (works). The Li-Po battery powers a buck/boost LED driver (works, too). However, this set-up is supposed to go on the top branch of a high tree, so manual operation is impossible. Therefore, I want to modify the set-up so that 1. the battery is charged from dawn to dusk, if sufficient insolation is present, and 2. the buck/boost LED driver is powered from dusk onwards until the battery is depleted; the same thing, day after day. After looking at various electronics for beginners projects, it seems I can get this to work with a p-channel MOSFET, simply using the PV solar panel as "dusk-onset detector". There should also be some hysteresis I suppose, but that could come in the next step.

I have no EE experience yet and hope you can look at the attached schematic, if this is the way to go, or if I need something else altogether.

Thanks!

 

I just have to ask: why do you want to attract insects to the top of a tree at night?

 

I just have to ask: why do you want to attract insects to the top of a tree at night?

So the invasive species I'm after is caught on a nearby adhesive substrate containing pheromones.

 

Without knowing the specifications of the boxes on your diagram it looks like you are on the right road.

 

The specifications of the parts are in the schematic. Which ones do you think are missing? I can add them no problem.

If this is a reasonable way to go, how would I calculate the right value for the gate resistor?

 

The specifications of the parts are in the schematic. Which ones do you think are missing? I can add them no problem.

If this is a reasonable way to go, how would I calculate the right value for the gate resistor?

The value of the gate resistor will make no discernible difference as the MOSFET gate current is negligible.

 

Thanks, so I put a 0Ω jumper there to begin with, and see how that goes.