| 摘要 |
PURPOSE:To reset a sound multiplex mode at chattering and hit of a power supply by providing a circuit to switch the transistor using the reset pulse of station searching micro computer. CONSTITUTION:When the main power source is turned on, station search microcomputer generates the reset pulse. The size of it is +5V which is small enough comparing with the rising time of ON and OFF of the power source. When this pulse is impressed to an emitter of switching transistor 18 of sound multiplex mode reset circuit, the transistor 18 becomes unoperatable during the time of this pulse, and a pin 9 of sound multiplex mode changing integrated circuit 20 becomes about 8V during this period during which sound multiplex mode is reset. In this way, reset of sound multiplex mode can be surely done even at chattering and hit of a power supply.
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