4QD controllers Motor Speed Controllers
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Contents this page

• Introduction
• Models
• Specifications
• Features
• Pictures
• Ordering and prices
• Instructions

Introduction

4QD's 4QD series (-200 and -300) are 4 quadrant motor speed controllers for 24v, 36v and 48v motors. The range has been reduced by discontinuing the older 4QD-150 controllers - the 4QD-200 may be used in place -and having one voltage option which works on any voltage 24v through 48v.

The controllers are designed to give short time currents in the range 200 to 300 amps. Although small they are fully electronic and need no external relays whatsoever. They have many failsafes built in for reliable long time use (and misuse).

The controllers are wide supply voltage range, 36v and 48v both working also down to below 24v, so there is no separate 24v or 36v version, the 48v version should be used.

4QD-300-48 is particularly well matched to The Lynch Electric Motor.

Models

• 4QD-200-24/48: 210 amps cold
• 4QD-300-24/48: 320 amps cold

Specifications

Features

• Gain adjustment.
• Ramps, adjustable on accel and decel.
• Electronic Ignition - Separate.
• Regen braking may be disabled by making an on-board link.
• Parking brake driver with Current limit and Anti-rollback.
• Reversing.
• Thermal shutdown.
• Battery discharge protection - feature only fitted on special request and may be enabled by user if required.
• Pot fault protection (resistance)
• High Pedal Lock-out
• Foot brake Inhibit input for interlock with mechanical brake etc.
• Forward - Off - Reverse operation is possible, detailed in application note.
• Brake Light Driver. Factory option, replaces Parking brake (subject to minimum quantity order).
• Wide operating voltage: 48v controller is fine for use between 18v to 47v (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 reversing even on the steepest hills.

The 4QD-200 and 4QD-300 are full Four-Quadrant chopper drivers suitable for speed control of battery operated motors up to 300A and voltages between 24 and 60. They give full control of forward and reverse acceleration and braking. They have been developed in conjunction with a top motor manufacturer and golf buggy manufacturers.

Input is suitable for a joystick (center zero) or for a single ended speed pot plus separate reversing switch (mode is selected on board by a movable link). There is an on-board adjustment to alter input sensitivity. Alternatively an external pot or switch can be added to give a user top-speed control.

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 could be over-ridden by the ignition switch.

Mechanical construction is such that the controller can be mounted in thermal contact with the vehicle chassis, so this acts as additional heatsinking, although this is not normally required.

Please consult the factory for variations to the above specification or for more information.

Pictures

Photographs are being added: click on the thumbnail for the full version.

4QD-300-48	4QD-300-48 without cover

Ordering and prices

Instructions

You can download the instruction manual, in PDF format, via our manuals and catalogues page.

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