| 摘要 |
1,014,928. Sensing conditions photo-electrically. ELECTRONICS CORPORATION OF AMERICA. Feb. 19, 1964 [Feb. 21,1963], No. 6992/64. Addition to 993,506. Heading G1A. The condition sensing apparatus of the parent Specification in which an avalanche breakdown radiation detector is connected in the secondary of a step-up transformer, the primary being connected to an A.C. source, is modified by the inclusion of a capacitor in the primary circuit to make the primary circuit series resonant when the detector has a high impedance and non-resonant when the detector is in avalanche breakdown. As described the transformer is an autotransformer 16 with detector 20 across the whole winding 18 and capacitor 14 in series with the primary section 19 of the winding. The ferrite-core inductors 30, 32 have a low impedence to the A.C. frequency, but a high impedance at 3kc/s to detect the pulses reflected into the primary on avalanche in detector 20. These pulses are passed by diodes 36, 38 to charge a capacitor 46 which discharges slowly into a capacitor 48. So long as diodes 36, 38 pass pulsesatat least 3 per second, the controlled rectifier 64 is made conductive and current flows through the relay coil 66. The condition sensed may be the presence or absence of a flame. |
