| 摘要 |
551,058. Thermionic relay circuits. LAMSON ENGINEERING CO., Ltd., and STEPNEY, W. J. Aug. 19, 1942, No. 13775/41. [Class 40 (v)] A thermionic relay circuit comprises a relay which is energized upon changes in the anode current of a grid controlled valve, and normally open switching contacts shunted by a condenser, which are adapted upon momentary closure by the carrier of a pneumatic tube conveying system, to connect the grid and anode of the valve, the condenser serving to prolong the duration of the change of anode current sufficiently to energize the relay. As shown, the anode circuit of a valve 1 including relay coil 2 is supplied from a secondary winding 14c through rectifier 12, condenser 9 and resistance 11. Momentary closure of contacts 6 gives a positive impulse to the grid and the change in anode current energizes relay coil 2'to close contacts 3 and 4. To ensure operation of relay 2, the impulse is prolonged by the provision of a condenser 8 shunted by a resistance 10. Contacts 3 provide a maintaining circuit for coil 2 through switch 5 while contacts 4 effect energization of a power circuit connected to 7. Specification 470,560 is referred to. |
