JPS58154944A - Signal matrix circuit - Google Patents

Abstract

PURPOSE:To obtain very simply stereo, monaural and sub signals from sound multiplex signals by providing resistors for split, switches and a phase inverting section, in a television receiver having a sound multiplex circuit of the West Germany system. CONSTITUTION:The rate of resistors is set as R8/R9=2/1, R11/R12=1/2, and R15/R16=2/1. In selecting the monaural mode, the switches S1, S3 are turned on and S2, S4 are turned off, and signals of (L+R)/6 applied to an input terminal 8a are outputted from both output terminals 8d, 8h. In selecting the submode, the switches S1, S2 are turned off and the S3, S4 are turned on, and signals of R/3 applied to an input terminal 8c are outputted from both the output signal terminals 8d, 8h. Further, in selecting the stereo mode, the switches S1, S3 are turned off, S2, S4 are turned on, signals of L/3 applied to an input terminal 8b are outputted to the output terminal 8d, and signals of R/3 applied to the input terminal 8c are outputted at the output terminal 8h.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal multiplex circuit for obtaining a desired audio signal from a received audio multiplex signal in a television receiver having a dual-German audio multiplex circuit.

The conventional West German system signal generator (IJ) circuit is shown in Figure 1 (
&), (b) K is rare in the circuit shown. (a) has L + R signals on the input side (L signal is the left signal, R signal is the right signal) and 2
Adding the R signal, the 2R signal is amplified by the inverting amplifier 1 with an amplification factor of 1/2, and the direct output signal R (-R:) is added to the adder 2. (b) adds the (L+R)/2 and R signals to the input side, the R signal is the 11 output signal, and the switch 3 output; if there is 84RK, (L+R
)/2 is amplified by an inverting amplifier 4 with an amplification factor of 2, and then sent to an adder 5.
Add the R signal at -L-R+H to output signal L(-
L).

However, the above signal ma) IJ Ri 9 circuit is 1/2 or 2
An inverting amplifier with twice the amplification factor was required.

The object of the present invention is to provide a signal amplifier for an audio multiplex circuit which can be configured with only resistors, switches, and phase inverters in principle, and does not require an inverting amplifier with an amplification factor of 1/2 or 2.
The purpose of the present invention is to provide an IJ bus circuit.

Examples of the present invention will be described below. FIG. 2 is a diagram showing an example of this, where one input terminal 6 is a terminal to which a (L+R)/2 signal as a main signal is applied, and the other input terminal 7 is a terminal to which an R signal as a sub signal is applied. Each signal passes through a capacitor C1 for DC cut, or a variable resistor VR for level adjustment, and a capacitor CI for DC cut, and is then connected to transistors Q+, Q! is joining the pace of Resistors R1 to R3 are used to set the bias of the transistor Q1, and resistors R4 to R are used to set the bias of the transistor Q2. The output signal of the transistor Q1 is taken out from its emitter by the DC cut capacitor Cs, C4, and the output signal of the transistor Q2 is taken out from the emitter by the DC cut capacitor C1, and from the collector by the DC cut capacitor C. . In this case, (L
A signal of R)/2 appears, a -RO signal appears at the collector of the transistor Q2, and a signal R appears at the emitter of the transistor Q2. Then, the signal (L+R)/2 appearing at the power supply terminal of the transistor Qs is inputted to the input terminal 8 of the analog switch 80 via the resistor R. It is mixed with the signal -R appearing at the collector of the analog switch 8 through the resistor RI
0 input terminal 8b K input. Further, the signal R appearing at the emitter of the transistor Ql is input to the input terminal 8c of the analog switch 8 via the resistors R11 to Rtt. The analog switch 8 includes four switches S1 to S4, which are controlled by a switch control circuit 9 with three manpower and four outputs. That is, the switch control circuit 9
When the monaural selection signal X, the sub selection signal y1, and the stereo selection signal 2 are input to the input signal, the switches S1 to S4 of the analog switch 8 are switched as shown in the following table. However, on is “
1", and "0" indicates off.

8d-8h are output terminals, and the output terminals ad-8f
are connected to an output circuit made up of resistors R1@5R1-, and output terminals 8g and ah are connected to an output circuit made up of resistors R, , R21.

FIG. 3 is an equivalent circuit of the circuit shown in FIG. 2, and the operation will be explained with reference to this. Each resistor is R@/R,=2/
1, R11/R11= 1/2, Rn/Rn=2
The ratio is set to 1/1, so the input terminal 8a of the analog switch 8 receives a signal of (L+R)/2.
3 signal (L + R)/6 is added, input terminal 8b
K is a signal (L + R) / 3 which is the signal of (L + R) / 2 reduced to 2/3 and a large signal -R / which is the signal of -R which is reduced to 1/3.
3), input terminal 8c K
A signal R/3, which is 1/3 of the R signal, is added.

For monaural selection, press ↓K and switch S in the table above.
1 and Ss are on, S! and 54 are turned off, the signal of (L+R)/6 applied to input terminal 8a is applied to both output terminals 8
Leave from d.8h. In addition, in the case of sub selection, switch S
1 and 52 are off and Ss and S4 are on, so
The R/3 signal applied to input terminal 8C is applied to both output terminals 8d.
Leaves at 8h. Furthermore, in the case of stereo selection, switches S1 and Ss are off, and S! and 54 is turned on, so
The L/3 signal applied to input terminal 8b is output terminal ad K
output, input terminal 8c R/3 signal added to output terminal 8
HK comes out.

Note that a signal of opposite polarity -
When (L+R)/2, -R is added, the output terminals 8d and 8hK of the analog switch 8 output signals with the opposite polarity of the signals shown in FIG.

As described above, according to the present invention, the dividing resistor, the switch, and the phase inverter are used, making it extremely simple.

It is characterized by being able to obtain stereo, monaural, and sub signals from West German audio multiplex signals.

[Brief explanation of the drawing]

Fig. 1 (II) and (1)) is a circuit diagram of a conventional signal matrix circuit, Fig. 2 is a circuit diagram of a signal matrix circuit according to an embodiment of the present invention, and Fig. 3 is a circuit diagram of a conventional signal matrix circuit. It is a circuit diagram of an equivalent circuit. 6.T...Input terminal, 8...Analog switch, 9
...Switch control circuit. L? (!¥ri, heat (early), (

Claims (4)

[Claims] (1) A first signal that is 1/3 times the main signal, a second signal that is 1/3 times the sub signal, and 2/3 the above main signal.
When monaural is selected, the first signal is sent to the left and right output terminals, and when 1 sub is selected, the second signal is sent to the left and right output terminals. respectively, and when stereo is selected, the first
A signal matrix circuit comprising a switch selection of the first to third signals so that the signal is output to one of the left and right output terminals, and the second signal is output to the other left and right output terminal. . (2) The IJ box circuit according to claim 1, wherein the main signal is (L+R)/2 and the sub signal is R. (3) The signal matrix circuit according to claim 1, wherein the first to third signals are obtained by resistor division. (4) The monaural selection, the sub-selection, and the stereo selection are performed by controlling an analog switch to which the first to third signals are input. signal matrix circuit.