GB1157954A - Control System for a Ship - Google Patents

Abstract

1,157,954. Control systems. EXPRESS TRANSFORMERS & CONTROLS Ltd. July 6, 1966 [April 7, 1965], No. 14781/65. Heading G1N. [Also in Division G3] The steering motor of a ship is energized to operate in one direction or the other by electronic switch means controlled by unbalance between a rudder feedback potentiometer and a potentiometer in a portable remote control unit connected through a wandering lead. In Fig. 1, operation in one sense or the other of a remote potentiometer 11 energized from a stabilized direct voltage supply 17 unbalances a bridge circuit including a pair of transistors 21, 22 so that a voltage of corresponding polarity is produced across resistors 26, 27 to render one or other of silicon controlled rectifiers 28, 29 conductive. A corresponding relay A or B then operates to cause a rudder servomotor 19 to run in a direction corresponding to that in which potentiometer 11 was moved, until a potentiometer 18 adjusted by servomotor 19 rebalances the bridge circuit. The supply to relays A, B, which is controlled by silicon controlled rectifiers 28, 29, is derived from a square wave generator including transistors 34, 35. Sudden voltage changes due to cable breakage are effective through a condenser C to render a silicon controlled rectifier 40 conductive to de-energize both relays A, B. Modifications are described in which the servomotor is supplied from an AC or DC source through silicon controlled rectifiers instead of relay contacts. For automatically maintaining the ship on a desired course, arrangements are described in which signals from an AC pick-off operated by a gyro compass are supplied to one of the transistors 21, 22 and signals from an AC potentiometer setting the desired course are applied to the other transistor. One of these arrangements involves a transistor amplifier having both positive and negative feedback.