| 摘要 |
1. An output coupling circuit for an audio-frequency ripple control receiver with a capacitive mains supply circuit in a full-wave rectifier design comprising a series capacitor (C1), where, on the mains input side, a protective impedance (R1 , R2 ) and a surge arrester (VDR) can be provided, where a Zener diode can be provided on the rectifier output side or in the full-wave rectifier (D1-D4) itself, and with a storage capacitor (C2 ) connected to the output of the capacitive mains supply circuit, where the storage capacitor (C2 ) is connected to an output coupling stage consisting of a differential amplifier (O1 , T1 ) directly connected to the storage capacitor (C2 ) for supply current, and having a first input connected to the tapping of a first potential divider whose first divider resistor (R3 ) is connected to the live mains terminal (R) and whose second divider resistor (R4 ) is connected to an earth potential point together with the storage capacitor (C2 ) where the second input of the differential amplifier (O1 , T1 ) is connected to the tapping of a second potential divider whose first divider resistor (R7 ) is connected to the earth potential point and storage capacitor (C2 ) and where the output of the differential amplifier (O1 , T1 ) serves as output (A) for the audio-frequency signal from the output coupling stage, characterised in that the second divider resistor (R6 ) of the second potential divider is connected to the neutral mains terminal (N), that the divider ratios of the first and second potential dividers are equal for an optimum compensation and that the output coupling stage is independent of frequency in the operating range.
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