Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JPS52114015 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing the principle of the present invention, and FIG. 2 is a circuit diagram of a specific embodiment. 3.4 ······· Diodes 2, 5, 8 ··· · · · · · · · ······················· Switch, 12, 15 ··········· Resistance, 13.14 ······diode. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an input switching circuit suitable for switching input signals of audio equipment and the like. -Conventionally, in audio equipment such as a radio receiver with stereo, as a changeover switch for switching different input signals and supplying the pre-amplifier, mechanically switch the contacts and switch like a rotary switch or a bush switch. Books have been used. However, in these switches, since the signal current flows to the switching terminal, noise at the time of switching, generation of crosstalk due to leakage between the switching terminals, distribution to the switching terminal Ii! 11, ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- There were drawbacks such as the increase of the number of switches of the company switch in the case of multi-channel, the increase of noise, and the increase of the number of switches. An object of the present invention is to provide an input switching circuit which can improve the performance and reduce the number of circuits of the switch without the disadvantages of the prior art described above. A feature of this invention is a circuit in which a diode is connected in the forward direction between the input terminal and the transmission circuit, a diode is connected in the reverse direction between the input terminal and the ground, and a positive or negative voltage is applied between the diodes. At the point where The invention will now be described by way of example with reference to the drawings. FIG. 1 shows the principle of the present invention, in which capacitors 1, 6 and a diode 4 are connected in series in the forward direction between an input end and an amplifier 7, and a 10-05-2019 1 resistor 2.5 and a diode 3 are connected. Connect to ground as shown. The common terminal of the changeover switch 9 is connected between the diodes 3.4 through the resistor 8. 4 ° C. ············· 1-2 [2 に お い て Suppose that the common terminal of the switch 9 is connected to the positive voltage element BK in the first 7 or more configuration. The diode 4 has a resistor 5. Resistor 8 is forward biased and diode 3 is reverse biased by resistor 8. Therefore, the diode 4 is turned on, the diode 3 is turned off, and the input signal is sent to the amplifier 7. Next, when the common terminal of the switch 9 is connected to the negative voltage -B, the diode 3 is forward biased and turned on, diode 4 is reverse biased and turned off, and the input signal is an amplifier Not transmitted to 7 Therefore, the switching operation can be performed only by switching the common terminal of the switch 9 to the positive and negative voltage sides. In FIG. 1, the resistors 2, 5 and 8 are largely selected so as not to affect the circuit. FIG. 2 shows a specific embodiment of the present invention, and shows a switching path between a phono signal and a tape signal. In the figure, 11 is a capacitor, 12.15 is a resistor, 13.14 is a diode, 10 is a switching switch, and3 switch is otherwise identical to that shown in FIG. The illustrated state indicates a phono state. That is, since the diode 3 is off and the diode 4 is on, the phono signal is transmitted to the amplifier 7, but the diode 15 is on and the diode 14 is off, so the tape signal is grounded and the amplifier 7yc is not transmitted. In the tape state, since the common terminal of the switch 9 is + IIK connected to the common terminal of the -B1 switch 10, the phono signal is grounded and the tape signal is transmitted. As apparent from the above description, according to the present invention, since the changeover switch switches only the DC voltage, no signal current flows in the changeover terminal. Therefore, noise at the time of switching, crosstalk due to leakage between the switching terminals, hum by the wiring to the switching terminals, noise, and the like can be improved. Further, since the number of switching circuits may be one, there are effects such as easy and economical application to multiple channels. 10-05-2019 2
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