actuated hj cams were attached to the base and so arranged to engage 

 when the camera cradle was pointed 80° down or 10*^ up (fig. Iia) . A 

 slight override on the motor after engaging limit switches gave an 

 effective vertical scanning range of 100*^. The override limit switches 

 and automatic reversing switch for the horizontal drive were mounted on 

 base welded lengths of 1" x 1" x 3/l6" angle iron. With the override 

 horizontal scanning of 370° was obtained. Three single pole, double- 

 throw switches were employed in the panel to operate horizontal scanning, 

 vertical scanning and horizontal manual-automatic controls. Each switch 

 had a center off position. These are indicated on the wiring diagram 

 (fig. 5). In order to use a minimum of control conductors the drive 

 motors were connected to operate as single pole motors. This allowed 

 the motors to be reversed by switching one wire. 



A leak detector and warning device was installed in the upper 

 pressure chamber so that the vehicle might be raised before any serious 

 damage could result (fig. 5). A phenol laminated terminal strip was 

 bolted to a base welded angle iron 1" x 1" x 3/l6". Two pieces of bare 

 strip copper l/l6" x 3/l6" were mounted to the lower section of the 

 terminal strip to serve as leak indicating electrodes. A sheet of resin 

 Ltipregnated fibre-glass .015" x l-l/U" x 2" insulated the electrodes 

 from the base plate. The soace between electrodes was l/l6" . The 



Fig. 5. Schematic Electrical System for Underwater Television 

 Vehicle. 



