Title:
METERING PULSE GENERATING CIRCUIT
Document Type and Number:
Japanese Patent JPH04265056
Kind Code:
A
Abstract:
PURPOSE: To keep the amplitude of a metering pulse fixed in a second time section by feeding back and coupling a metering pulse through a feedback circuit and discharging a capacitor to a reference voltage level in each period of a sine wave AC voltage. CONSTITUTION: A multiplication circuit MULT multiplies a current IC from a slaped ramp signal generator RAMP by a voltage VTTX for generating a metering pulse P. It passes a band filter BF, together with a voice signal SP, and an output 9a of a comparison circuit is made conductive, only when an output voltage UF exceeds a reference voltage UR. When a metering control signal D opens a switch SW in the ramp signal generator, a capacitor C1 is charged to raise an voltage VC linearly. When the voltage UF reaches the reference voltage UR, the capacitor C1 is minutely charged/discharged in each period of the AC voltage to keep the voltage VC fixed. A current IC is kept fixed in proportion to it and is fed back and coupled to keep the amplitude of the metering pulse at a designated value.
Inventors:
HANSU ARENIUSU
Application Number:
JP27603491A
Publication Date:
September 21, 1992
Filing Date:
October 24, 1991
Export Citation:
Assignee:
ERICSSON TELEFON AB L M
International Classes:
H04M15/00; H04M15/10; H04M15/28; (IPC1-7): H04M15/00
Attorney, Agent or Firm:
Akira Asamura (3 outside)