| 摘要 |
PURPOSE:To automatically set the sound volume according to the distribution of passengers sitting in a car, by converting a signal obtained from sitting condition sensors of each seat into a fader balance control signal and selectively controlling plural loudspeaker outputs. CONSTITUTION:The 7A-7D of the diagram are sitting condition sensors installed to seat A-D, respectively, the 8 is a data converting section using an ROM which is accessed by using parallel 4-bit sitting sensor signals SA-SD, and 9 is an attenuation controlling section which selectively attenuates audio signals L and R to be given to loudspeakers FL, FR, RL, and RR by 4-bit fader balance control signals CLF, CFR, CRL, and CRR outputted from the converting section 8. The attenuation controlling section 9 controls the audio signal L to the loudspeaker FL by turning on a transistor TR when the control signal CFL is ''1'' or turning off the transistor TR when the control signal CFL is ''0''. The same processing is performed for the other control signals. |
