Patent GB-1224024-A (GB)
Title: Logic assisted systems
IPC: G05B19/10
Filed: 1968-03-01
Abstract: 1,224,024. Voltage measurement. JAMES G. BIDDLE CO. March 1, 1968 [March 3, 1967] No.10066/68. Heading G1U. A system for incorporation in and facilitating the adjustment of apparatus requiring multiple adjustment in a sequence of steps incorporates a separate manually operated adjuster for each step of adjustment, sensing arrangements for providing outputs representing the effect of each adjustment operation, a logic system responding to the sensed outputs and indicators associated with each adjuster, the indicators being controlled by the logic system in a sequence determined by the order in which their associated adjusters are to be operated, and each giving instructions in response to the logic to an operator on what adjustment is to be accom-' plished, when in the sequence it is to be accomplished by the adjuster, and when it is completed. The system is particularly described with reference to a voltage measuring potentiometer which is to be adjusted to balance an unknown voltage at successively increasing sensitivity levels, but the invention is stated to be generally applicable to any system requiring a sequence of adjustments to be made, e.g. as in starting a vehicle engine. In the potentiometer system, the unknown Ex is attenuated by a range changing circuit 40 and then compared in a sensitivity divider 41 with a reference voltage derived from a Kelvin-Varley type potentiometer 42. The voltages tapped from a point in the sensitivity divider and from the potentiometer 42 are compared by a differential amplifier 46 to provide an output which is fed to a circuit 54 which provides two related outputs, 1 and 2. Output 1 operates either relay 5X or 6X, depending on its polarity, and whichever of those is energized controls the supplies to appropriate indicator display circuits and to the logic control circuits. Output 2 is only provided when the output from amplifier 46 is above a given level, indicating that a reduction in sensitivity in the divider 41 is necessary. The relay switches start in the positions shown in Fig. 5, the divider 41 being set to its most sensitive position. If this causes an excessive output from the amplifier 46, relay 1X is energized so that contacts 1X4 are opened and 1X5 closed to switch to the next, lesser sensitivity level. Contacts 1X2 close, so that relay 2X will be energized if output 2 is still excessive. The procedure continues until relay 4X is energized and the divider is in its least sensitive condition. Relay 4X is latched on as the contact 4X1 closes, by the supply E L , and closes contact 4X7 and opens 4X8, Fig. 6. In accordance with the direction of the error voltage, lamp 5L or 6L is illuminated. Adjustment of the Kelvin-Varley potentiometer at that level of sensitivity is carried out, until balance is achieved and relay 4X drops out, so that contacts 4X8 close and lamp 12 is illuminated, to point to the next stage to be adjusted. Adjustment proceeds in a similar way through the various levels of sensitivity, until final balance is achieved. A system is provided incorporating the switches S2-S5, for enabling errors in previous decimal places to be corrected.