A solicitação
“Draw a solar battery overcharge protection circuit with an 18 V solar panel, blocking diode, 12 V battery, capacitor, adjustable resistor divider and shunt transistor.”
Depois, tenteChange the battery to 24 V.Add a fuse between the panel and diode.
O que há neste desenho
Entenda as decisões por trás dele.
01
Use an NPN transistor across the solar panel output to shunt excess current when overvoltage is detected.
02
A resistor divider from battery positive sets the threshold, with values chosen so the transistor base reaches ~0.7V at the maximum safe battery voltage.
03
A blocking diode prevents battery backfeed through the shunt transistor during normal charging.
Small off-grid solar battery chargers where a simple discrete shunt regulator is sufficient and adjustable threshold is preferred over fixed IC solutions.