Specifications

Curtis PMC 1223/33, 1225/35, 1227/37 Manual
A-10
APPENDIX A: GLOSSARY
netic brake mechanically released. The controller, even if it is powered off and
there are no batteries in the system, will detect the motor voltage created by the
moving vehicle. When this voltage becomes high enough, indicating that signifi-
cant vehicle speed has been reached, the controller logic will power up and turn
on the MOSFET power sections to short the motor and limit the speed of the
vehicle.
PWM
Pulse width modulation (PWM), also called “chopping,” is a technique that
switches battery voltage to the motor on and off very quickly, thereby controlling
the speed of the motor. Curtis PMC 1200 series controllers use high frequency
PWM—15 kHz—which permits silent, efficient operation.
Ramp shape (static throttle map)
The ramp shape parameter determines the controller’s static throttle map.
Adjusting the throttle characteristics to suit your specific application can enhance
your vehicle’s performance. The ramp shape parameter is programmable—see
Section 3, page 38.
Regenerative braking
The 1223/33, 1225/35, 1227/37 controllers use regenerative braking to slow the
vehicle to a stop and to reduce speed when traveling downhill. Regenerative
braking means that the energy used to slow the vehicle is channeled back into the
batteries, resulting in longer vehicle range between charges.
Regen current boost
By allowing the regenerative braking current to be set up to 25% higher than the
main drive current limit, this feature can provide the higher braking torque
necessary to stop very heavy vehicles on steep inclines. The regen current boost
parameter (“Calibration 5” in the Program Menu) is programmable—see Section
3, page 40.
Reverse polarity protection
If the B+ and B- connections are reversed to an otherwise properly wired
controller, it will not allow the main contactor to be engaged. This protects the
power MOSFET output section from being damaged by the reverse polarity.