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Do 4QD controllers have constant torque mode?

Constant torque mode is the same as constant current control. The new Pro-160 has direct motor current sensing and uses this to implement a fully adjustable current limit. The software to provide a full torque control mode is being developed.

The 4QD-200 & 300 have an adjustable current limit which can be used to limit the torque from the motor.

Remember that the standard current limit is there solely to protect the MOSFETs from transient over-currents which could be destructive. If you run on the standard current limit for too long, then the controller will simply overheat and melt – quite literally, it is indeed possible to melt the solder on the MOSFET leads before the controller fails! So you may need to reduce the current limit quite significantly. The exact allowable current will of course depend on your heatsinking, the motor, and the controller you use.

Do 4QD controllers have closed loop control?

Closed loop control

The Pro-160 has been designed with a speed control sensor input. Software for this will be coming soon.

The SST-031 has a spare input port that can be used with a speed sensor. Software for this can be written by the user.

The Pro-150, 4QD series, DNO, and Porter controllers can have closed loop control implemented via our tacho feedback board.

Can I disable regen braking?

Disabling regen braking can be done on certain models

  • The following controllers can have regen braking disabled by an on-board link
    • 4QD series
    • Pro-120 Mk 2
    • VTX series


  • The following controllers can have regen braking disabled by cutting PCB tracks
    • DNO series


  • The following controllers have regen braking which cannot be disabled
    • Porter
    • Pro-150