Curtis MultiMode 1207B - Throttle Map; Throttle Types; Undertemperature Protection; Undervoltage Protection

2 9 J U N E 2 0 1 2 D R A F T
APPENDIX A: GLOSSARY
Curtis 1207B Manual
A-11
Throttle map
The throttle map (duty factor as a function of throttle position) is adjustable,
so that you can provide the proper feel for the many types of vehicles that use
the 1207B controller. The throttle map parameter is called “ramp shape”; see
Ramp shape for more information.
Throttle response
The dynamic throttle response (duty factor as a function of
time) is shaped by
the acceleration rate setting. Dynamic throttle response is linear. The newest
throttle input is mapped to the throttle map, and the controller then automati
-
cally accelerates (or decelerates) through a straight line until the new throttle
demand is obtained.
Throttle types
The 1207B controller accepts a variety of throttle inputs, through various
combinations of its four throttle input pins. The most commonly used throttles
can all be hooked up directly: 5k
Ω–0 and 0–5kΩ 2-wire rheostats, 3-wire pots,
0–5V throttles, and the Curtis ET-XXX electronic throttle.
Throttle full range produces 0–100% duty factor at the controller output
(unless limited by other conditions). Throttle fault detect is performed on the
throttle input signals and virtually eliminates the possibility of runaway op
-
eration. Adjustments and settings are independent of throttle type. However,
throttle fault conditions will vary by throttle type.
Undertemperature
When the controller is operating at less than -25°C, the current limit is cut back
to approximately one-half of the set current. The operating PWM frequency is
shifted to 1.5 kHz when the controller is operating at undertemperature.
Undervoltage protection
Undervoltage protection automatically disables the controller output if battery
voltage is detected below the undervoltage point at start-up, or when the bat
-
tery voltage is pulled below the undervoltage point by an external load. The
undervoltage cutback point is set in ROM, and is not adjustable.
During normal operation, the controller duty factor will be reduced when
the batteries discharge down to less than the undervoltage level. If the motor
current is such that the batteries are being pulled below the minimum point, the
duty factor will be reduced until the battery voltage recovers to the minimum
level. In this way the controller “servos” the duty factor around the point which
maintains the minimum allowed battery voltage.