Cradle Wiring

The cradle stage wiring section of this manual contains descriptions of the rotation stage wiring and associated systems for the cradle portion of the DEIMOS Spectrograph. It corresponds to the Cradle Stage Wiring tab in the electronics schematics binder.

Shuttle Drive System, EL-3123

Schematic: schematics\SHUTTLE.sch.pdf
Page last updated: February 19, 2003

Simplified Drawing

The above drawing show the wiring for the 'tractor' that moves the DEIMOS instrument in and out of the elevation baring on the Nasmyth platform. The motor is show at the top, right corner of the drawing. When not in a limit or in 'slow down' mode, the Install/Remove pushbuttons control the movement and direction of the motor. As the note in the center of the drawing suggests, the reverse direction on the motor moves the carriage into the telescope baring and the forward direction moves the carriage away from the baring. The end of travel limit switches are labeled Remove Halt Limit for removing the carriage and Install Halt Limit for installing the instrument into the baring. The motor speed is controlled by the Run/Stop switch and the Speed Control rheostat in the lower, left hand corner of the drawing. The Run/Stop switch control the 115 VAC control circuitry. In the Stop position the 115V is not available to supply either the F, R or IR relay coils. Without power, the FWD and REV contactors can not supply the 208 VAC power to the motor. When power is turned on the direction contactors are controlled by the F and R coils. The coils are in turn controlled by the Install and Remove pushbuttons on the control paddle. Note that when one button is pushed it breaks a contact in series with the opposite direction pushbutton.
The speed at which the motor, and thus, the carriage move is determined by one of two rheostat settings. The IR relay coil (Internal Rate) in the upper center of the drawing controls wheether the motor runs at the speed setting of the control paddle or at it's internal setting. The contacts of the IR relay are shown at the bottom, center of the drawing. The internal rate is called Slow Down Setting on the schematics. The IR relay is energized whenever one of the Slow Down Limit switches are activated. These limit switches are set several inches in front of the normal end of travel limit switches. Thus, the carraige will slow down before it reaches either limit. The actual speed control is handled by an Eaton #15-47 Control Unit. This box applies the voltage to the motor and actuates the clutch.