Circuit Design Help
Solar Panel (60 cell mono panel) Open circuit voltage 36.4V DC, Short circuit current 7.96A.
Pump 12 V DC, 9A max
Using E=IR , R=E/I, (36.4-12)/7.96 = 3 ohms
Power = V(sq)/R = 24.4/3 =198 watts
I purchased a resistor that meets these requirements and hooked everything in series. (Solar panel lead to resistor, resistor to pump, and pump to other solar panel lead.
The pump does not turn on when the panel is in the sunlight.
I measure the voltage coming out of the panel and it is within specification.
I also tested the pump by hooking it up to a car battery and it works fine.
Any ideas what I am doing wrong?