Specifications

Curtis PMC 1223/33, 1225/35, 1227/37 Manual
A-6
APPENDIX A: GLOSSARY
HPD lockout (procedural/wiring fault)
After 5 seconds of a continuous HPD fault, driving is inhibited until power to the
controller is cycled. This feature prevents operation of a vehicle with a defective
or misadjusted throttle.
Inhibit
The inhibit input is used to put the vehicle in a safe, non-drivable state during
battery charging or under other conditions where this precaution is desired—see
Section 2, page 25.
IR compensation
IR compensation is a technique used to provide near-constant speed control of the
vehicle during varying motor loads despite resistive motor losses (IR). Internal
circuitry monitors the current and voltage in the motor relative to throttle position
and adjusts the controller output to maintain as constant a speed as possible during
varying motor loads. The motor load varies as a function of inclines/declines in
terrain or when the vehicle encounters an obstacle, such as debris on the sidewalk.
The programmable IR speed coefficient parameter adjusts how aggressively the
controller tries to maintain constant speed under changing load conditions—see
Section 3, page 44.
ISO pot fault
All 1223/33, 1225/35, and 1227/37 controllers contain throttle pot fault circuitry
that meets ISO 7176 requirements.
Key off deceleration
The key off deceleration feature provides controlled deceleration—rather than an
abrupt stop—when the keyswitch is turned off for any reason while driving.
KSI
KSI (Key Switch Input) provides power to the controller’s logic board, initializes
the microprocessor, and starts diagnostics. If both a keyswitch and a power enable
switch are used, the keyswitch will provide power to the controller’s logic but the
power enable switch must also be activated in order to drive the vehicle. The
keyswitch functions as a master switch for the vehicle, to turn the system off when
not in use.