| 摘要 |
<p>1497690 Positive arrangements for amplifiers SONY CORP 16 May 1975 [21 May 1974] 20906/75 Heading H2K A push-pull amplifier 4a, 4b directly coupled to a load 7 (e.g. a loud-speaker) is disabled if any D.C. appears at its output terminal 6 by shorting both its input and output to ground. Any D.C. component at the output terminal 6 charges a capacitor 10 until either transistor 15 or transistor 16 (depending on the polarity of the D.C.) is switched on to short the input signal from driver amplifier 2 to ground via diode 17 or 18. At the same time, the voltage drop across base resistor 13 or 14 switches transistor 19, and hence transistor 21, on, thereby triggering a thyristor 23 to short the output terminal 6 to ground via diode bridge 22. Relays may replace the transistors 15, 16 and thyristor 23.</p> |
