| 摘要 |
PCT No. PCT/AU86/00208 Sec. 371 Date May 11, 1987 Sec. 102(e) Date May 11, 1987 PCT Filed Jul. 22, 1986 PCT Pub. No. WO87/00709 PCT Pub. Date Jan. 29, 1987.Audio amplifier comprising symmetrical, dual polarity power supply and class AB audio amplifier circuit, said supply comprising first positive (86) and negative (85) and second positive (83) and negative (84) unregulated DC inputs; positive and negative regulated outputs and common output (87); first regulator circuit including transistor (62) having its emitter connected to said first negative unregulated DC input; a second regulator circuit including transistor (61) having its emitter connected to said positive unregulated DC input and both collectors connected to said common output, each transistor having a pass resistor, said first circuit deriving a reference from said negative regulated output and said second circuit deriving a reference from said positive regulated output said first and second regulator circuit deriving power from said positive regulated output and common and said negative regulated output and common respectively; said amplifier circuit comprising primary operational amplifier (12) driving complementary power transistor output stages (9, 10); bias adjustment means responsive to temperature of the output stages; the signal output of said operational amplifier being fed to complentary symmetric arms of a network shunting base current from said output stages when said signal exceeds a threshold and, at the same time, said power output drops below a threshold; said network allowing transient overloads.
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