JPS54100778A - Sound volume indicator - Google Patents

Abstract

PURPOSE: To indicate the adjusted condition of a sound volume in a remarkably readable manner by gating the sound volume control pulses, which have their width modulated, with the use of gate pulses in different positions to detect their duty ratios so that indicating lamps may be lit in response to the outputs detected.

CONSTITUTION: A gate pulse generating circuit 12 either extracts the start and end pulses at a pulse width changing circuit 8 or divides the frequency of the clock signals from their generating circuit 6, while resetting the frequency dividing circuit in response to the signals from the circuit 8, so that sixteen gate pulses may be generated at different positions in synchronism with the clock signals and in a manner to correspond to sound volume control pulses. The respective gate pulses are fed to gate circuits 13a to 13p, respectively, and control pulses and muting pulses are fed to the aforementioned gate circuit. A sound volume control circuit 7 generates signals for adjusting the sound volume, and the circuit 8 generates the control pulses of corresponding duty ratios to adjust the sound volume. At that time, only the gate circuit, to which the gate pulses are fed, are rendered conductive so that indicating lamps 14a to 14p of the number corresponding to the sound volume adjusted are lit.

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