KR0141960B1 - Id signal detecting apparatus - Google Patents

Abstract

No content

Description

Recognition signal detection device

1 is a block diagram of a conventional recognition signal detection device

2 is a block diagram of a recognition signal detection apparatus according to the present invention

Figure 3 (a) is a waveform diagram of each part in stereo according to the present invention

(b) is a waveform diagram of each part of the dual time in accordance with the present invention

* Explanation of symbols for main parts of the drawings

10: AM detector 20: wave former

30: One-short timer 40: R.C charge and discharge circuit

50: D flip-flop 60: level comparator

70: state discriminator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a recognition signal (ID) in an apparatus for receiving a multiplexing voice. In particular, the apparatus for detecting a multiplexing broadcast signal (ID) for detecting an identification signal (ID signal) using a one-shot timer. It relates to a detection device.

The conventional recognition signal (ID signal) detecting apparatus has a sine frequency (SIF) of 149.8 HZ (stereo broadcast) or 276 HZ (dual broadcast) on a 55 KHZ carrier transmitted from a broadcasting station during voice multiple broadcasting as shown in FIG. Is 50% amplitude modulated and connected to the input of the amplitude modulator demodulator of the TV receiver, and the output of the amplitude modulator demodulator detects the dual phase and the first phase locked loop circuit 2 which detects the stereo broadcast via the AM detector 1. Simultaneously applied to the second phase locked loop circuit 3 and the output to the first phase locked loop circuit 2 are connected to the cathode of the light emitting diode LD1 and grounded through the capacitor C1 and the second phase locked loop. The output of the (Phase Locked Loop) circuit 3 is connected to the cathode of the light emitting diode LD2 and is grounded through the capacitor C2, and each anode of the light emitting diodes LD1 and LD2 is connected to the resistors R1 and R2. Connected to the power supply (Vcc) .

In the conventional ID signal detection device configured as described above, when a sine frequency, which is a recognition signal of 149.8HZ or 276HZ, is 50% amplitude modulated to a 55KHZ carrier transmitted during voice multiple broadcasting, it is transmitted to an input of an amplitude modulation demodulator of a TV receiver. The recognition signal (ID signal) is demodulated in an amplitude modulation demodulator.

The ID signal for determining the voice multiple broadcast status during voice multiple broadcast is 50% AM modulated to 150HZ for stereo, 148HZ for dual broadcast, and 0HZ for mono broadcast on a 55HZ carrier.

When this ID signal is applied to the AM detector 1 and detected, a 276HZ or 150HZ (149.8HZ) sine wave is output from the AM detector 1, and this signal is applied to the first and second phase locked loops (PLL) so as to detect each signal. Will be detected. That is, in stereo broadcasting, the first phase synchronization loop (PLL) 276HZ is locked at 150HZ to notify the stereo state, and in dual broadcasting, the second phase synchronization loop (PLL) is locked at 276HZ to recognize the dual state.

However, in the conventional circuit as described above, two phase locked loops (PLLs) are used, and the system is complicated, and the free run frequency must be adjusted in the production line. There was a disadvantage that would be wrong.

The present invention has been made to solve the above shortcomings. By using the one-shot timer to detect the ID signal, the system is simplified and the reliability is improved. In case of broadcasting, it converts to mono to prevent malfunction. This will be described in detail with reference to the accompanying drawings.

)와 연결되고 D플립 플롭(50)의 Q출력은 상태 판별기(70)로 인가되고 R·C 충방전 회로(40)의 출력은 레벨 비교기(60)를 거쳐 상태 판별기(70)로 인가되는 구성이다.First, as shown in FIG. 2, a sine frequency (SIF) signal is applied to a wave shaper 20 through an AM detector 10, and the output of the wave shaper 20 is an R-C charge / discharge circuit. 40 is simultaneously connected to the D input terminal of the one-shot timer 30 and the D flip flop 50, and the output of the one-short timer 30 is connected to the clock terminal of the D flip flop 50 (

), The Q output of the D-flop flop 50 is applied to the state discriminator 70, and the output of the R-C charge / discharge circuit 40 is applied to the state discriminator 70 via the level comparator 60. It is a configuration.

Referring to the operation state of the configuration circuit, when the sine frequency (SIF), that is, the ID signal passes through the AM detector 10 and passes through the wave shaper 20, the stereo (149.8HZ) is shown in FIG. In the dual (276HZ) case, the waveform becomes the 'E' waveform in FIG. 3 (b), and the output E of the wave former 20 is connected to the D terminal of the flip flop 50 and the RC charge / discharge. It is input to the circuit and simultaneously applied to the one-short timer 30.

)로 인가되고 R·C 충방전 회로의 출력(G)은 스테레오시는 제3도(a)의 'G'파형과 같고 듀얼시는 제3도(b)의 'G'파형과 같이 되어 레벨 비교기(60)로 인가되는데 이때 레벨 비교기(60)의 출력은 '하이'되어 상태 판별기(70)로 인가된다.The output of the one-short timer 30 is equivalent to the 'F' waveform in FIG. 3 (a) in stereo time and the 'F' waveform in FIG. Clock terminal

And the output G of the RC charging and discharging circuit is the same as the 'G' waveform in FIG. 3 (a) in stereo and the 'G' waveform in FIG. The output of the level comparator 60 is 'high' and is applied to the state discriminator 70.

That is, in stereo or dual time, the output level of the R / C charge / discharge circuit 40 is designed to be higher than the reference voltage of the level comparator 60, so that the output of the level comparator 60 becomes 'high'.

The Q output of the D flip flop 50 is 'low' for stereo and 'high' for dual and is applied to the state discriminator 70 to discriminate between stereo and dual states.

At this time, the pulse time T of the one-short timer 30 output F is greater than the wave shaper 20 output E pulse time T1 in stereo and the wave shaper 20 output E pulse time T2 in dual time. It is designed smaller than).

That is, it is determined to satisfy the condition of T1TT2, and the time constant of the R-C charge / discharge circuit 40 makes the charging time short and the discharge time considerably longer. Since the output E of the wave former 20 is kept low during mono broadcasting, and the level of the output G of the RC charging / discharging circuit is lower than that of the level comparator 60 during the weak electric field. The output A of the level comparator 60 is 'low' during mono broadcasting or the weak power, and the output A of the level comparator 60 is 'high' during stereo or dual broadcasting.

That is, in the weak electric field, even if the broadcast state is in stereo or dual broadcast, it is recognized as mono.

The state discriminator 70 inputs the states of the output A of the level comparator 60 and the output B of the D flip-flop 50 as inputs to the output terminals C and D to be 'high' or 'low'. Is output. The I / O states of the status discriminator are shown in Table 1 below.

That is, in stereo (see the waveform of FIG. 3 (a)), the 149.8HZ sine signal is output by AM detection at the AM detector 10, and the waveform passing through the wave former 20 is 'E' in FIG. 3 (a). Waveform.

The one-short timer 30 is synchronized with the output E of the wave former 20 so that the 'F' waveform of FIG. 3 (a) is output so that the clock signal C of the D flip flop 50 is generated. Since the output E waveform of the wave generator 20 is 'low' at the time t1 which is the operation time of the D flip flop 50, the Q output of the D flip flop 50 becomes 'low'. Since the output G level of the R.C charge / discharge circuit 40 becomes 'high' in stereo, the output A of the level comparator 60 also becomes high. By the 'high' output of the level comparator 60 and the 'low' output of the D flip flop 50, the output C of the state discriminator 70 becomes 'high' and D becomes 'low'.

)가 되는데 D플립 플롭(50)의 동작 타임이 되는 t1 시간에 웨이브 형성기(20)의 출력(E)파형이 '하이'이므로 D플립 플롭(50)의 Q출력은 '하이'가 된다.In the dual time (see waveform of FIG. 3 (b)), the 276HZ sine signal is detected by the AM detector 10 and outputted, and the waveform passing through the wave former 20 is the 'E' waveform of FIG. The one-short timer 30 is synchronized with the output E of the wave former 20 so that the 'F' waveform of FIG. 3 (b) is output and the clock signal of the D flip flop 50 (

However, since the output E waveform of the wave former 20 is 'high' at the time t1 at which the operating time of the D flip flop 50 is 'high', the Q output of the D flip flop 50 is 'high'.

In addition, since the output G level of the R.C charge / discharge circuit 40 becomes 'high' in dual time, the output A of the level comparator 60 also becomes 'high'.

By the 'high' output of the level comparator 60 and the 'high' output of the D flip flop 50, the output C of the level comparator 60 becomes 'low' and D becomes 'high'.

In the mono time, there is no output (E) signal of the wave former 20, and the outputs of the R / C charge / discharge circuit 40 and the level comparator 60 go low and the output 'C' of the state discriminator 70 And 'D' are both 'low'.

Therefore, the present invention has the effect of simplifying the system and increasing the reliability by detecting the identification signal (ID) using the one-short timer. Also, it detects the weak electric field and converts it to mono in the case of stereo or dual broadcasting to prevent the malfunction of the weak electric field. It is effective.

Claims (1)

A wave shaper 20 for forming a wave in the recognition signal ID detected by the AM detector 10 to output a signal in two states according to stereo and dual time, and outputting a low when mono; Receives the wave signal received by the wave shaper 20 and outputs a waveform having a pulse time T having a value T1TT2 between a half period of a stereo pulse time T1 and a dual pulse time T2. The one-short timer 30 and the output pulse of the one-short timer 30 are clock signals (

D-flop that receives the output of the wave shaper 30 as the D input and outputs a 'low' for stereo and a 'high' for a dual output to the Q output terminal. 50) and the charge and discharge of the output of the wave former 20 so that the stereo and dual time output signals of the 'high' level, and the mono and weak field output the 'low' level signals. The output of the discharge circuit 40 and the R-C charge / discharge circuit 40 is input and compared with a reference voltage to output high when stereo and dual time and low when mono and weak electric fields. A level comparator 60 and a state discriminator 70 for discriminating between states of stereo and dual and mono and weak electric fields according to the output of the level comparator 60 and the output of the D flip flop 50. Recognition signal detection apparatus, characterized in that configured.

Images