I am using a 7.2 Ampere-hour Sealed Lead Acid Battery
to power a 12V DC motor
which is driving a fan, and I need to understand how to control the fan speed.
When I power a 12V DC LED strip directly from the battery there are no issues, so the battery works fine. But when I instead connect a DC motor or a DC Fan directly to the battery, the speed is way too fast and I am concerned about possibly damaging the motor.
The motor takes about 500-700mA current. I have seen in many answers that 500mA capacity would mean the device would draw only 500mA, even if higher amperage is available. Is this also true of DC motors?
Can someone guide me on how I can regulate the current supplied by the battery, to control the speed of the motor? Since I am just starting out, I want to understand how to implement both a fixed-speed
control solution and a variable-speed
control.
Would simply adding a resistor in series with the load reduce the supply current and thus control the fan speed? If so, how would I select the component and would there be any other issues? Or is there a better solution?