Glossary: Features And Functions - Curtis 1204 Manual

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Curtis PMC 1204/1205 Manual
FEATURES and FUNCTIONS
Acceleration rate
A built-in acceleration rate circuit maintains a maximum rate of power
increase to the motor. If the throttle is applied full on at start-up, the
acceleration rate setting determines how quickly the controller output
increases. The standard setting is such that with the throttle full on, the
controller requires approximately one second to reach full output. This
feature contributes to smooth, gentle starts.
On some 1204/1205 models, the acceleration rate is adjustable via an
externally accessible trimpot. See Section 4 for adjustment instructions.
The deceleration rate is fixed, and cannot be adjusted.
Accelerator pot fault protection
To prevent uncontrolled operation, these controllers shut off the motor
in the event of an open circuit fault in the accelerator potentiometer or its
wiring. The standard configuration is a two-wire pot ranging from 0 ohms
for full off to 5000 ohms for full on; if the controller detects an abnormally
high accelerator input (more than about 1.5 times the normal input
resistance), it shuts off its output to the motor, thus preventing a runaway.
The controller returns to normal operation when the fault (e.g., broken
potbox wiring, broken connectors) has been repaired.
Current limiting
Curtis PMC controllers limit the motor current to a preset maximum.
This feature protects the controller from damage that might result if the
current were limited only by motor demand.
In addition to protecting the controller, the current limit feature also
protects the rest of the system. By eliminating high current surges during
vehicle acceleration, stress on the motor and batteries is reduced and their
efficiency and service life are improved. Similarly, there is less wear and
tear on the vehicle drivetrain, as well as on the ground on which the
vehicle rides (an important consideration with golf courses and tennis
courts, for example).
Current multiplication
During acceleration and during reduced speed operation, the Curtis PMC
controller allows more current to flow into the motor than flows out of the
GLOSSARY:
(runaway protection)
GLOSSARY
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