OVERLOAD PROTECTIVE GEAR FOR PUSH-PULL POWER AMPLIFIER Russian patent published in 1999 - IPC

FIELD: radio engineering; overload protection of high-power amplifier stages. SUBSTANCE: protective gear has in each amplifier side resistive sensor of load current and voltage, protective transistor, differential capacitor compensating for load current phase lagging, and voltage regulator diode compensating for voltage drop across protective transistor base. Provision is also made for resistor that functions to limit pulse current of protective transistor base and variable resistor compensating for rated difference in parameters of circuit components. Protective circuit is designed so that its self-excitation is impossible at any kind of non-matched load impedance, pulse overloads of output stages are reduced and they do not pass throughput currents; amplitude of dissipation power instant values at output stages (for any type of load and any voltage across it) is brought to value approaching rated-load power limit. EFFECT: improved operating reliability of protective gear. 5 cl, 2 dwg