| 摘要 |
PURPOSE:To make a metronome into IC construction and small-sized through eliminating the need for a time constant circuit, by logically synthesizing attenuating timbre with controlling a ladder circuit consisting of plural resistances, a gate circuit, etc. CONSTITUTION:A sound-source reference signal is frequency-divided by FFs 11-16 to control gates 20-23, forming the ladder circuit of a timbre synthesizing part together with resistances 24-27, and 28-30, through the FFs 13-16. On the other hand, those FFs 13-16 are reset with a tempo signal passed through a differentiating circuit D and controlled by the high-level set output of an FF18 inverted through a gate 17 when the FFs 14-16 are at high levels. Therefore, a timbre sound attenuating stepwise is generated at a ladder circuit terminal 31 corresponding to the tempo signal. This system which synthesizes the attenuating timbre logically without using a time constant circuit realizes an electronic metronome which is easily made into IC construction and small-sized. |
