GB278388A - Apparatus for indicating the time interval elapsing between the sending and receipt of an impulse, such as sounding apparatus, or the like - Google Patents

Abstract

278,388. British Thomson-Houston Co., Ltd., (Assignees of Langmuir, I.). Oct. 2, 1926, [Convention date]. Void [Published under Sect. 91 of the Acts]. Thermionic valve circuits.-In apparatus for measuring small intervals of time, particularly applicable to the determination of depths and distances by means of reflected waves of sound, a rotating pointer 29 carries a neon tube which is caused to flash when the impulses from a transmitting device 1 are received by a microphone 4 or the like. The pointer 29 is rotated at a constant speed by a motor, and, when in the vertical position, is adapted by means of a contact 35 and a slip ring 36 to close relay 3 so as to energize the transmitting device 1. The impulses are reflected from the ocean bed 37 to the receiver 4, and are applied through a transformer 11<1> to the grid circuit of an amplifier 5, which is coupled by a transformer 16 to a vapour electric tube 6. The change in grid potential renders the tube 6 conductive, and so allows a condenser 25 to discharge The condenser is energized from a sources 7 and the resulting discharge current, acting through a transformer 24 and slip rings 32, 33, '' flashes " the neon lamp on the pointer 29. The distance which the pointer 29 has rotated from its vertical position when the flash appears determines the depth of the water, this depth being indicated on a scale 28. To measure the time an impulse takes to travel from the device 4 to a given point, a, second receiving device located at that point is connected to a transformer 16<1> through an amplifier similar to 5. An impulse emitted from a transmitter close to the device 4 is immediately received thereby, and after a certain interval is received by the second receiver, the time interval being indicated by the successive flashes of the neon tube, as the pointer 29 travels over the scale 28.