Service manual

Electrical Service Manual V4.0
2
2-2
CURTIS 1203A CONTROLLER
CONNECTIONS
BATTERY
The connections from the controller to the battery are made via 0.25” quick connects
(Spade terminals). The positive battery cable connects from the main circuit breaker to
any one of the 3 terminals labeled “B+”. The negative battery cable connects to any one of
the 3 terminals labeled “B-”.
POWER SWITCH
The power switch is a very simple circuit. +24 volts is taken from the main circuit breaker
and it is switched on and off to the controller thru a SPST lighted switch. The signal is sent
into the controller thru a 16 gauge red wire into pin #6 of the P1 connector.
THROTTLE
The throttle uses a 5K hermetically sealed potentiometer to sum the high and low reference
from the controller. The output from the potentiometer is a varied voltage from +0.2 volts
+/- 0.1 volt to 4.8 volts +/- 0.1 volt. This signal is then sent to the reverse switch and the
handle bar buttons or bail assembly. Either one of these switches closes the circuit pass-
ing the varied voltage signal through to the controller on pin #2 of the P1 connector.
REVERSE SWITCH
The reverse switch circuit is very simple. There is a pair of wires that go to one pole of the
DPDT switch. When this switch is activated this pole of the switch completes the circuit
telling the controller that the machine should be going in reverse. The other pole of the
DPDT switch send the throttle signal to the controller causing it to move.
BRAKE OUTPUT
The brake output of the controller is used to turn a solenoid on and off the controls when
the brushes run. This output is turned on by the controller immediately when the machine
is put in motion and stays on for 1 second after the throttle input is turned off.