| 摘要 |
<p>901,084. Phase-sensitive circuits. MINNEAPOLIS-HONEYWELL REGULATOR CO. Aug. 13, 1958 [Aug. 14, 1957], No. 26018/58. Class 38 (4). In a phase-sensitive circuit for selectively energizing relays 124, 154 in accordance with the sense of unbalance of a temperature or humidity measuring A.C. bridge (not shown), a centre-tapped transformer 27 and rectifiers 42, 43 supply load resistors 70, 71 on alternate halfcycles, and a transistor 23 in series with the common return is biased by the amplified output of the bridge so as to increase and decrease, respectively, the load currents through resistors 70, 71 according to the phase relationship between the bridge output and the reference supply to transformer 27. Transistor 23 is direct-coupled to the amplifier transistor 15 which has an input from the bridge at 10, 11 and is biased by a constant current source 90. There is D.C. negative feed-back from across the load resistors 70, 71 via resistors 75, 76 to stabilize the collector currents of the transistor against the effects of temperature changes or ageing. The output voltage across the load resistors operates the relays 124 or 154 through transistor switching circuits 96, 100 and 107, 113.</p> |
