A constant-current controller that supplies a constant-current to a solenoid driver for use with an electromechanical device. The controller comprises a PCB containing a constant-current control circuit. The circuit comprises a GaNFET primary switch and a secondary switch. The PCB is integrated with and made a part of the solenoid driver. A standard electromechanical device may be converted to a constant-current controlled electromechanical device by exchanging the solenoid driver.