Specifications

Curtis PMC 1223/33, 1225/35, 1227/37 Manual
A-13
APPENDIX A: GLOSSARY
Throttle fault protection
5kΩ, 3-wire potentiometer throttle
For 5kΩ, 3-wire potentiometer throttles, the throttle fault detection circuitry
meets ISO 7176 requirements. Also, throttle pot resistances outside the range of
4.5–7.5 kΩ are considered to be indicative of a faulty pot or faulty wiring, in
which case the controller will register a pot fault. Fault detection causes the
controller to decelerate to zero output. The controller returns to normal operation
when the fault has been repaired.
0–5V throttle
Because the throttle input voltage is referenced to B- and no connection is made
to the pot high and pot low inputs, complete throttle pot protection is lost with
0–5V throttles. Only a broken wire fault to the pot wiper input will be detected
by the controller. Therefore, it is the responsibility of the vehicle manufacturer
to provide throttle fault detection for 0–5V throttles.
Throttle gain (see Throttle: restricted range)
Throttle map
The static throttle map (duty factor as a function of throttle position) is adjustable,
in order to provide the proper feel for the many types of vehicles that use the 1223/
33, 1225/35, and 1227/37 controllers. The throttle map parameter is called “ramp
shape,” and is programmable—see Section 3, page 38.
Throttle response
The dynamic throttle response (duty factor as a function of time) is shaped by the
acceleration and deceleration rate settings. Dynamic throttle response is linear.
The newest throttle input is mapped to the throttle map, and the controller then
automatically accelerates (or decelerates) through a straight line until the new
throttle demand is obtained.
Throttle: restricted range
The 1223/33, 1225/35, and 1227/37 controllers can be programmed for use with
restricted range throttle inputs via the throttle gain parameter—see Section 3, page
37. This capability allows throttle pots with less than 5kΩ total full stroke wiper
resistance to be used.