| 摘要 |
PURPOSE:To reduce the size and improve the sound quality of a tape recorder by interchanging a microphone and a speaker with the use of an electronic switch, which is arranged in position, so that the weak signals of the microphone and head may be converted into a low impedance. CONSTITUTION:In the common vicinity of the microphone 4 and magnetic head 23 of a recorder which is equipped at its center with a mechanism, there is arranged an IC electronic switch 26 which is composed of CMOS inverters 35 to 39. If a mechanicl switch 28 is changed to a reproducing condition, a transistor 50 is rendered inconductive to leave a bias oscillator 32 inoperative,and a control line 33 takes a negative potential so that the P terminals of the inverters 35 and 36 and the N terminals of the inverters 37 to 39 are rendered conductive. As a result, the output reproduced by the head 23 is converted by a conversion transistor 60 into low impedance signals, which are fed to a speaker 44. Like operations are followed during the recording operation, in which the change is made to the microphone 24. The signal and control lines are separated by the electronic switch at a proper position to dispense with the shield wire so that the size of the recorder can be reduced while improving the sound qulity. |
