GB173071A - - Google Patents

Abstract

173,071. McKinlay, A. B. Sept. 23, 1920. Indicators, electric. - In apparatus for indicating the level of a liquid in which a float automatically varies a resistance according to the level, a differentially wound voltmeter 1 preferably of the deadbeat type is used to indicate the level directly. This voltmeter mav be provided with two oppositely-wound coils 2, 3, in parallel, one of which is in series with a coil of wire 10 wound on an insulated core inserted in the tank. The pitch of the coil 10 preferably varies inversely as the section of the tank at any point. A float 16 in the form of a ring with spring contact-pieces is mounted to slide on the resistance coil, one contact-piece sliding on an earthed metal strip 15 and the other on the resistance coil, the lower end of which is connected by a wire passing up the centre of the insulating core to a terminal 11. For use on a moving vehicle the float and core may be enclosed in a tube having an air-vent and perforations to admit liquid from the tank. A handswitch 7 is inserted in the circuit, and if the vehicle has a dynamo charging cells, a switch operated by the dynamo cut-out may be provided in parallel with the hand-switch 7.