| 摘要 |
1,000,275. Keying carrier frequencies. COMPAGNIE DES FREINS ET SIGNAUX WESTINGHOUSE. Nov. 23, 1961 [Nov. 28, 1960], No. 41888/61. Heading H3R. An oscillator normally biased to cut-off by a bias source R3, R2 across the supply voltage S is keyed on by a switch M, introducing an additional bias after a delay due to the charging time of capacitor C1 and resistance R4, and then due to rectifier D generates a self-bias across C1 maintaining oscillations even after switch M is again opened. R1 is the output circuit. Oscillation is stopped again on opening the supply switch A. The choke L may be transposed to the collector circuit. A triode valve may replace the transistor. The circuit may be used as an on-off binary data storage device in railway signalling apparatus. |
