| 摘要 |
PURPOSE: A speaker output signal switching device of a handsfree system is provided to protect an amplifier by inserting a normal close type relay between a signal switching relay and a speaker and instantly interrupting a circuit of the speaker when the other signal introduced at the point when one signal being used is in blank is reproduced. CONSTITUTION: A switching relay(32) is connected to an audio signal input unit(10) for transmitting a signal from an audio set and a signal input unit(31) for transmitting a signal of a mobile phone, and switched to a speaker(20) installed in a car. When a signal is inputted from the mobile phone through the signal input unit(31), a controller(33) generates an output signal, connects the switching relay(32) to the mobile phone and reproduces the output signal to the speaker(20). A short relay(34) is connected to one of negative line and positive line between the relay(32) and the speaker(20).
|
