| 摘要 |
973,088. Bridge circuits. GENERAL ELECTRIC CO. Ltd. Nov. 6, 1962 [Nov. 7, 1961], No. 39840/61. Heading G1U. [Also in Division H4] An electrical comparator for use e.g. in the multichannel pulse code communication system described in Specification 973,087 comprises a bridge 4 including two arms formed by semiconductor junction diodes biased to act as voltage variable capacitors across which, respectively, the voltage being compared and a standard voltage are applied, an oscillator 10 connected across one diagonal of the bridge and an amplifier 12, which receives an input from the other diagonal of the bridge, connected via a limiter 13 to a phase sensitive demodulator 14, which also receives an input from the oscillator and provides a positive going pulsed output when the bridge is on one side of balance and a pulsed output of opposite polarity when the bridge is on the other side of balance. When impedances 19, 20 are also compositive the voltages between points 3, 7 and earth are in phase with the oscillator output and when the voltage applied at terminals 1, 2 across diode 17 exceeds the standard voltage applied at terminals 21, 22 across diode 18 the signal output of the limiter is in phase with the oscillator voltage and when the standard voltage is the greater the output from the limiter and the oscillator are in antiphase. Specification 973,089 also is referred to. |
