GB599370A - Improvements in multiple electrical recording systems - Google Patents

Abstract

599,370. Electric measuring systems. KEINATH, G. March 16, 1944, No. 4945. Convention date, Dec. 24, 1942. Addition to 581,977. [Class 40 (i)] In a system for recording a number of measurements, the variable elements to be measured are connected sequentially by a contact device to a ,variable circuit member, such as a potentiometer, the adjusting member of which is driven round continuously and operates a relay when it reaches a point on the variable member indicative of the magnitude to be measured and so causes a mark to be made on the recording sheet. In the Figure shown, the voltage from a pick-up coil 111 is applied across the potentiometer 120, a point being reached in the rotation of the contact arm 125 when the voltage applied to relay 167 is large enough to cause it to operate and close contact 170. The condenser 171 then discharges and makes a mark on the recording drum 151, which is driven at the same speed as the contact device 140. The potentiometer contact 125 is driven through gearing 130 so that it completes one revolution while the contact 145 of the contact device 140 passes over one segment, zero lines are marked on the recording sheet by arranging that every time contact 125 passes over contact 0 the relay is energized from battery 186. In a modification, Fig. 2 (not shown), the pick-up coils are connected as one arm of a Wheatstone bridge, a point of balance being obtained in the rotation of the potentiometer contact, when the relay closes the switch contacts. In another arrangement, Fig. 4 (not shown), a variable condenser is used instead of the potentiometer. The system is applicable to testing aircraft, the impulses produced by the discharge of the condenser being transmitted to a distant recording mechanism and the recorder drum being driven in synchronism with the potentiometer contact or other adjustable element. Specification 556,134 is referred to.