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Cryoclaw/Elevator
THEORY OF OPERATION
The Cryoclaw/Elevator mechanism consists of two gear-reduced motors controlled by the game CPU.
Several opto switches are used to detect the positioning of the motors. Attached to the claw is an
electromagnet, which is used to pick up the pinball during game play.
Elevator:
The elevator motor runs in only one direction. The CPU pulses the motor control input, rather
than turning it on solid, in order to slow its speed. The elevator has a single opto (index) switch for
detecting the DOWN position of the elevator. Due to the inertia of the motor, it is normal for the
elevator motor to be stopped with the switch activator just beyond the index switch.
Claw:
The claw motor runs in both directions. The CPU pulses the motor control inputs to vary the
speed of the claw arm. The claw has two opto switches for detecting the position of the claw arm.
The switch states for the arm positions are:
Claw Right SwHch
OFF (blocked)
OFF (blocked)
ON (open)
ON (open)
Claw Left Switch
OFF (blocked)
ON (open)
OFF (blocked)
ON (open)
arm out of range
arm at right (above the elevator)
arm at left (away from elevator)
arm within range of motion
When both position switches are OFF (blocked) the CPU cannot determine the position of the arm. In this
case, the CPU will not tum on the claw motor, since it does not know whether to move the arm to the left or
the right. To reposition the arm when it is out of range, use the CLAW TEST. Do not attempt to move the
claw by hand.
Note that if the position switches are disconnected, the CPU will think that the claw arm is out of range.
During game play, the Cryoclaw/Elevator is operated both automatically, and under player control. During
multiball play, the claw is always operated automatically. The claw is also operated automatically during ball
search.
The CPU monitors the operation of the Cryoclaw/Elevator to detect malfunctions. When the CPU has
detected a malfunction, it will not open the diverter on the right ramp leading to the Cryoclaw/Elevator.
The Cryoclaw/Elevator can also be disabled by option setting, in case of an intermittent error.
ERROR MESSAGES
The game test report will display an error message when the CPU has detected a maHunction of the
Cryoclaw/Elevator. These error messages are explained below.
Claw Disabled
This message is displayed when the Cryoclaw/Elevator is disabled by option adjustment.
Arm Out of Range
This message is displayed when the claw arm is positioned out of range. This message can also
be caused by one or more broken claw position opto switches.
Elevator Broken
This message is displayed when the CPU cannot detect an activation of the elevator index opto
switch. This can be caused by either a broken switch, or a non-functional elevator motor.
DEMOLITION MAN 1·38