Patent GB-633411-A (GB)
Title: Automatic weather station
IPC: G01W1/00
Filed: 1946-06-21
Abstract: 633,411. Automatic weather stations. BENDIX AVIATION CORPORATION. June 21 1946, No. 18762. Convention date, July 18, 1945. [Class 40 (i)] A device for transmitting signals as to the readings of a number of instruments for indicating the weather at a remote position comprises sensing means which determine the reading of each instrument and an electromagnetic selector switch which allows the reading of each instrument in turn to control the signalling of a wireless transmitter. As shown, a barometer and a wind vane control the positions of associated Selsyn transmitters which are connected in turn to a Selsyn receiver 35, Fig. 2, the position of which is signalled with the aid of a constantly-driven arm 39, which transmits a code signal in a reference position 66, 67 and a further signal when its position agrees with that of the clamped needle 58 of the Selsyn receiver 35. In further positions of the sequence switch, the radio transmitter is keyed under the control of an interrupter driven by an anemometer. Detailed operation.-A signalling cycle is initiated by a clock controlled contact which gives an impulse to a six-bank uniselector which steps on to its first terminals and energizes a relay 69 which remains mechanically latched and closes circuits for winding the clock, starting the radio transmitter and driving an inverter 34, supplying 400 cycle current for operating the Selsyn apparatus, code wheel 36, switch-operating cam 37 and sensing arm 39. Shortly before the cam completes each revolution it gives a driving impulse to the uniselector which on position 2 energizes keying relay 105 to send out a continuous tone. In position 3 the keying relay is controlled by the codewheel, the needle of the receiver Selsyn is unclamped and the Selsyn itself is connected to the distant barometer-controlled Selsyn transmitter (not shown). After the code a reference signal is sent by engagement of the sensing arm 39 with contact 66, the number of impulses in the signal identifying the instrument. In positions 4 to 6, the needle of the receiver Selsyn is clamped and the keying relay is operated under control of the sensing arm which sends an impulse when it reaches the clamped Selsyn needle and a reference code at the end of each rotation. The time between the preceding reference code and the signal is thus a measure of the instrument reading. In position 7, a steady tone, timed by cam contacts 48, 51 is transmitted and contact 67.is substituted for 66 to give a different reference signal when engaged by the sensing arm. At the same time the Selsyn needle is unclamped and the Selsyn is connected to the wind-vane controlled transmitter. In positions 8 to 10 the needle is again clamped and signals are sent in accordance with its position, and in position 11 a steady tone is sent. In positions 12 to 14 the keying coil is actuated via wiper E and wires 96, 98 by interrupter contacts, not shown, controlled by the distant anemometer. In position 15, magnet 70 is operated to unlatch relay 69 and stop the inverter &c., and the uniselector goes home by self-interruption.