A linear power controller system may be implemented that includes locked-rotor protection circuitry that is primarily assembled using analog circuit components. The locked rotor protection circuitry may be part of a power module in the system. The power module may be a switched power source that includes temperature circuit. A control loop may be established in the system to maintain the voltage across a motor that is driver by the power module. Circuitry for establishing a close loop with a motor may be positioned in a control head in the system or in a power module in the system. Temperature protection circuitry may be integrated into a current source in the power module to provide automatic thermal shutdown of the current source. The linear power module may specifically include analog circuitry that is arranged to establish a control loop with the motor.