| 摘要 |
A modulation amplifier having an output amplifier element which contains an accumulation choke, a switching tube and a low-pass filter connected in series, with a commutation diode connected to the switching tube is disclosed. The switching tube is controlled by pulse duration-modulated pulses and a semiconductor switch is connected between the switching tube and the pulse duration-modulated pulses. The semiconductor switch comprises two branches, each of which are connected to a different electric potential and each including a controlled semiconductor which acts as a switch, one of the branches being controlled into a conducting state and the other of the branches being controlled into a non-conducting state upon a potential jump in the pulse time-modulated pulses in either the increasing or decreasing directions. The modulation amplifier may further include a control circuit for stabilizing at least one of the potentials, which comprises a switch element as a primary control element which is controlled by an auxiliary pulse duration-modulated signal. A chopper is provided with following filter means for providing an actual value to be fed to the control circuit, which is derived from the output voltage of the filter means.
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