The 4QD-200 and 4QD-300 are heavy duty motor controllers for currents up to 300A. The key features are:
- 4 quadrant operation
- Gain adjustment.
- Adjustable acceleration and deceleration ramps.
- Input by 1k ohm to 22k ohm potentiometer, direct voltage control, or PWM control by Pi or Arduino etc.
- Regenerative braking [can be disabled].
- Over temperature shutdown.
- Battery discharge protection.
- Pot fault protection.
- High Pedal Lock-out.
- Inhibit input for interlock with mechanical brake, deadmans handle etc.
- Parking brake driver with current limit and anti-rollback.
- Joystick (center zero) or single ended modes [selected by a movable link).
- Forward – Off – Reverse push button operation is possible [see article in knowledge base]
- Wide operating voltage: 48v controller can be used between 18v to 66v (subject to battery discharge protection setting).
- Fail-safe, protected circuitry for reliable, safe operation even into a shorted output: no minimum inductance for safe operation.
- Shut down circuitry shuts drive down safely under all likely failure modes, including internal or battery over and under voltage
- Reversing speed threshold can be adjusted for operation on hills.
- Brake Light Driver. Factory option, replaces parking brake (subject to minimum quantity order).
- 3 heatsink options available, standard, finned air, or water cooled.
Also on board is an adjustable torque limit, which limits the continuous motor current, to avoid overloading smaller motors.
Direction switching and drive / brake switching is entirely electronic so in a vehicle equipped with a 4QD it is quite permissible to change the direction switch whilst travelling at full forward speed. The 4QD will brake, stop and reverse under full control. There are on board ramp controls to separately adjust acceleration and deceleration rates. With maximum rates the controller is very lively!
Output devices are kept in their safe operating area so failures are rare. However 4QD have considered the possible failure mechanisms. Worst would be an output device failing short-circuit so the drive would go to full speed. Such failures normally cause the MOSFET gate to go short-circuit. This condition is normally detected by internal circuitry and shuts the controller off completely and safely. Control circuit failures can be over-ridden by the ignition switch.
The standard 4QD series uses a large aluminium plate as the primary heatsink, this has a high heat capacity and is usually sufficient for the majority of applications. However for currents at the upper end of the envelope, or for extended operating times then additional measures to disperse heat should be considered e.g.
- Mounting the controller so that it is in thermal contact with the vehicle chassis.
- Fitting a PC case type fan.
- Fitting one of our finned or water cooled heatsink options these can be added at the build stage or retro-fitted.
Please consult the factory for variations to the above specification or for more information.