A new wireless transmitting station signal source switching system

Abstract

This utility model discloses a novel wireless transmitter source switching system, comprising a loop control module, a signal output module, a signal detection module, a working indicator module, and a signal input module. The signal output module, signal detection module, working indicator module, and signal input module are electrically connected to the loop control module. A power control module is electrically connected to each of the loop control module, signal output module, signal detection module, and working indicator module, and is powered by AC mains electricity. This utility model relates to the field of automatic source switching for wireless broadcast transmitters, specifically a novel wireless transmitter source switching system.

Description

Technical Field

[0001] This utility model relates to the field of automatic switching of signal sources for wireless broadcasting transmitters, specifically to a novel wireless transmitter signal source switching system. Background Technology

[0002] A stable signal source is crucial for broadcasting. However, signal interruptions are inevitable due to unforeseen circumstances, such as fiber optic cables being severed during municipal construction or satellite signals being interrupted or interfered with by unforeseen events. In such cases, operators must quickly switch to a backup signal source. Relying on manual switching is becoming increasingly outdated, and its reliability depends heavily on the operator's monitoring during their shift.

[0003] To ensure safe broadcasting, advanced technologies are used to enable the signal source to quickly complete signal detection and switching without human intervention. Utility Model Content

[0004] The problem this invention aims to solve is to achieve signal source detection and high-speed switching without manual intervention, thereby improving the reliability of the broadcast system, ensuring more efficient and reliable safe broadcasting, and reducing the workload of duty officers.

[0005] To solve the above problems, the technical solution adopted by this utility model is as follows: This utility model is a novel wireless transmitter source switching system, including a loop control module, a signal output module, a signal detection module, a working indicator module, and a signal input module. The signal output module is electrically connected to the loop control module, the signal detection module is electrically connected to the loop control module, the working indicator module is electrically connected to the loop control module, and the signal input module is electrically connected to the signal detection module. A power control module is electrically connected to the loop control module, the signal output module, the signal detection module, and the working indicator module, and the power control module is powered by AC mains power.

[0006] Furthermore, the signal detection module includes a voltage follower circuit, an inverting voltage amplifier circuit, a rectifier filter circuit, a voltage comparator circuit, and a signal detection output circuit. The voltage follower circuit is electrically connected to the signal input module, the inverting voltage amplifier is electrically connected to the voltage follower circuit, the rectifier filter circuit is electrically connected to the inverting voltage amplifier circuit, the voltage comparator circuit is electrically connected to the rectifier filter circuit, and the signal detection output circuit is electrically connected to the voltage comparator circuit and is also electrically connected to the loop control module.

[0007] Furthermore, the voltage follower circuit and the inverting voltage amplifier circuit are integrated into a set of LM324 chips, and the voltage comparator circuit is implemented using another set of LM324 chips.

[0008] Furthermore, a fault indication circuit is electrically connected to the signal detection output circuit.

[0009] Furthermore, the loop control module includes a loop control core chip, a first logic comparison circuit, a second logic comparison circuit, an audio detection module, a working indicator circuit, and a switch circuit. The first logic comparison circuit is electrically connected to the loop control core chip, the second logic comparison circuit is electrically connected to the loop control core chip, the audio detection module is electrically connected to the second logic comparison circuit, the working indicator circuit is electrically connected to the loop control core chip, and the switch is electrically connected to the loop control core chip.

[0010] Furthermore, the first logic comparison is equipped with a manual switching and reset button.

[0011] The beneficial effects of this utility model by adopting the above structure are as follows:

[0012] 1. The fully automatic detection and switching of the signal source was completed through reliable digital circuit technology, which has high reliability and completely solves the problem of the past broadcast system relying on manual intervention for switching, effectively ensuring safe broadcasting without interruption.

[0013] 2. It can accurately determine whether the signal source is interrupted and provide the duty officer with intuitive fault signal source location through fault indicator lights, thereby improving the duty officer's fault handling efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall modules of this utility model;

[0015] Figure 2 This is a schematic diagram of the signal detection module of this utility model;

[0016] Figure 3 This is the circuit diagram of the signal detection module of this utility model;

[0017] Figure 4 This is a schematic diagram of the loop control module circuit of this utility model;

[0018] Figure 5 This is the circuit diagram of the loop control module of this utility model;

[0019] Figure 6 Circuit diagram of the low-voltage power supply for the automatic source switching system of this utility model;

[0020] Figure 7 This is a diagram showing the source output and operating indication of the automatic source switching system of this utility model;

[0021] Figure 8This is a diagram of the chassis panel of the wireless transmitter automatic source switching system of this utility model;

[0022] Figure 9 This is a block diagram illustrating the principle of the automatic source switching system of this utility model applied to a medium-wave transmission system. Detailed Implementation

[0023] As per the instruction manual Figures 1-3 As shown, this utility model is a novel wireless transmitter source switching system, including a loop control module, a signal output module, a signal detection module, a work indication module, and a signal input module. The signal output module, the signal detection module, the work indication module, and the signal input module are electrically connected to the loop control module. A power control module is electrically connected to the loop control module, the signal output module, the signal detection module, and the work indication module, and the power control module is powered by AC mains power.

[0024] The signal detection module includes a voltage follower circuit, an inverting voltage amplifier circuit, a rectifier and filter circuit, a voltage comparator circuit, and a signal detection output circuit. The voltage follower circuit is electrically connected to the signal input module, the inverting voltage amplifier is electrically connected to the voltage follower circuit, the rectifier and filter circuit is electrically connected to the inverting voltage amplifier circuit, the voltage comparator circuit is electrically connected to the rectifier and filter circuit, and the signal detection output circuit is electrically connected to the voltage comparator circuit and also electrically connected to the loop control module. The voltage follower circuit and the inverting voltage amplifier circuit are integrated into a single LM324 chip, utilizing both operational amplifiers within the chip. The voltage comparator circuit is implemented using another set of LM324 chips. A fault indication circuit is electrically connected to the signal detection output circuit.

[0025] As per the instruction manual Figure 3 As shown, the first operational amplifier of the LM324 acts as a voltage follower in a voltage follower circuit. Utilizing the high input impedance and low output impedance characteristics of operational amplifiers, and based on the negative feedback principle, when the input signal changes, the amplifier adjusts its amplification factor according to the adjustment signal from the feedback circuit, ensuring the output signal remains consistent with the input signal. A DC bias signal superimposed on the positive input is transmitted unchanged to the next stage.

[0026] As per the instruction manual Figure 3As shown, the second operational amplifier of the LM324 acts as an inverting amplifier in the inverting amplifier circuit, and the amplification factor is determined by the absolute value of R102 / R101. The larger the absolute value of the amplification factor, the smaller the amplitude of the detectable signal. That is, the sensitivity of the circuit can be adjusted by adjusting the absolute value of the ratio of R102 / R101. C101 is a countermeasure to prevent low-frequency noise interference. Since the capacitive reactance of the capacitor is 1 / (j*w*C), the capacitive reactance is very large for low-frequency signals and close to a short circuit for high-frequency signals.

[0027] As per the instruction manual Figure 3 As shown, the signal needs to be rectified and filtered after being processed by the inverting amplifier circuit. The rectifier circuit composed of D101, C102, and R103 can effectively smooth the amplitude of the amplified signal, making it close to a DC signal! When the voltage difference across diode D101 is greater than the diode's forward voltage, the diode conducts, charging capacitor C102 (while some current flows through R103 and the comparator's input impedance); when the voltage difference across D101 is less than the diode's forward voltage, the diode is cut off, and the charge on the capacitor discharges through R103 (and the comparator's input impedance). When the voltage difference across D101 is again greater than the diode's forward voltage, the diode conducts, and the charging process begins again. This circuit repeatedly performs this charging and discharging process. Because the values ​​of R103 and C102 are both large, the discharge speed is very slow, and the capacitor voltage is close to DC. From the differential equation, we can obtain that the discharge time T = RCln(Vo / Vt), where Vo is the initial discharge voltage, and Vt is the discharge voltage. The longer the discharge time, the less easily the voltage changes.

[0028] As per the instruction manual Figure 3 As shown, the third operational amplifier of the LM324 acts as a voltage comparator in the voltage comparison circuit. The rectified and filtered signal is input to the positive signal terminal (pin 10) of the LM324 comparator and compared with the +5V voltage at the negative terminal (pin 9) of the LM324. When the signal level is greater than 5V, the comparator outputs a high level; when the signal level is less than 5V, the comparator outputs a low level.

[0029] The detection circuit determines the detection signal by controlling whether transistor Q101 is turned on or off based on the output of the voltage comparator. When Q101 is turned on, the collector output of Q101 is pulled low, and the output of the detection circuit is low, indicating that there is audio input from AUX.

[0030] As per the instruction manual Figures 4-5As shown, the loop control module includes a loop control core chip, a first logic comparison circuit, a second logic comparison circuit, an audio detection module, a working indicator circuit, and a switching circuit. The first logic comparison circuit is electrically connected to the loop control core chip, the second logic comparison circuit is electrically connected to the loop control core chip, the audio detection module is electrically connected to the second logic comparison circuit, the working indicator circuit is electrically connected to the loop control core chip, and the switch is electrically connected to the loop control core chip. The first logic comparison circuit has a manual switching and reset button.

[0031] The core chip for loop control uses the CD4028B, an integrated chip with four-bit BCD code input and a 10-bit decoder output. Its function table is as follows:

[0032]

[0033] As can be seen from the above function table, when all inputs of CD4028B are 0, output Q0=1, Q1-Q9 are 0, and working indicator lights D301-D304 are not lit.

[0034] After pressing switch S5, pin 2 of CD4071 is input with a high level. According to the truth table of the OR gate, pin 3 of CD4071 is also 1, that is, A=1, B=0, C=0, D=0. At this time, Q1=1 and the rest are 0. Therefore, D304 lights up the green light, and switch D of CD4066B is turned on, realizing the signal source output.

[0035] At the same time, the output of Q1 is fed back to pin 1 of CD4071. According to the truth table of the OR gate, pin 3 of CD4071 will continue to maintain a high level output, that is, Q1=1 is maintained.

[0036] If X101 of the current signal source is high (an interrupt has occurred), meaning the output of SN74S08 is high, the input to pin 5 of CD4071 will be high, and the output to pin 6 will be high. According to the truth table of CD4028B, B=1, A=0, C=0, D=0, and Q2=1. Switch C of CC4066 will be turned on, and switch D will be turned off, thus switching the second signal source. Using the above switching logic, automatic detection and switching of four signal sources can be achieved.

[0037] This loop control circuit also has a circuit reset function. When S1 is pressed, pins 9 and 13 of CD4071 are at high level. At this time, the state of DCBA is 1100. According to the truth table, outputs Q0-Q9 are all 0, all switches of CC4066 are closed, and the reset is completed.

[0038] As per the instruction manual Figure 6As shown, transformer T401 converts 220V AC mains power to 9V AC power. After full-wave rectification and filtering, the three-terminal voltage regulator IC (7808) regulates the voltage and outputs a stable +8V DC power supply for use by LM324, CD4028B, and CC4066B. The three-terminal voltage regulator IC (7805) regulates the voltage and outputs a stable +5V DC power supply for use by LM324, SN74S08, CD4071B, and other integrated circuits.

[0039] As per the instruction manual Figure 7 As shown, after receiving the control signal, the electronic switch CC4066B completes the connection, realizing the output of the signal source and the illumination of the working indicator light.

[0040] As per the instruction manual Figure 8 As shown, the front panel features a four-channel manual source switching button and indicator lights, as well as a power switch with indicator lights. The rear panel features four XLR input connectors, two XLR output connectors (achieving 1+1 redundancy backup), a fuse holder, and a power socket.

[0041] As per the instruction manual Figure 9 As shown, the signal sources of the wireless transmitter include, but are not limited to, fiber optic signals and satellite signals. The radio transmitter implemented in this example has four signal sources: a primary fiber optic signal source, a backup fiber optic signal source, a primary satellite signal source, and a backup satellite signal source. The outputs of all these signal sources are connected to the input of an automatic source switching system. The output of the automatic source switching system is connected to the input of an audio processor. The output of the audio processor is connected to the input of an input switcher. The output of the input switcher is connected to the input of the transmitter. The transmitter is connected to the transmitting antenna to complete the broadcast signal transmission into the air. This block diagram clearly shows that the source switching system is a core device in the entire transmission system. Its existence enables multi-source redundancy backup for the transmission system. When the primary signal source (such as the primary fiber optic signal source or the primary satellite signal source) fails, such as due to fiber optic line damage or satellite signal interference, it can quickly switch to the backup signal source (the backup fiber optic signal source or the backup satellite signal source), ensuring a continuous signal input to the transmission system, maintaining normal broadcast transmission, and avoiding signal interruption that could cause program interruptions. It also improves signal quality and flexibility. Different signal sources exhibit varying signal quality under different environments and conditions. For example, in some regions, fiber optic signals may become unstable due to network congestion, while satellite signals may maintain good quality. Alternatively, under specific weather conditions, satellite signals may be affected, making fiber optic signals more stable. A signal source switching system can flexibly switch to the optimal signal source based on the actual signal quality, ensuring high-quality transmission of the transmitted signal.

[0042] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A novel wireless transmitter source switching system, characterized in that: It includes a cycle control module, a signal output module, a signal detection module, a work indication module, and a signal input module. The signal output module is electrically connected to the cycle control module, the signal detection module is electrically connected to the cycle control module, the work indication module is electrically connected to the cycle control module, and the signal input module is electrically connected to the signal detection module. A power control module is electrically connected to the cycle control module, the signal output module, the signal detection module, and the work indication module. The power control module is powered by AC mains power.

2. The novel wireless transmitter source switching system according to claim 1, characterized in that: The signal detection module includes a voltage follower circuit, an inverting voltage amplifier circuit, a rectifier filter circuit, a voltage comparator circuit, and a signal detection output circuit. The voltage follower circuit is electrically connected to the signal input module, the inverting voltage amplifier is electrically connected to the voltage follower circuit, the rectifier filter circuit is electrically connected to the inverting voltage amplifier circuit, the voltage comparator circuit is electrically connected to the rectifier filter circuit, and the signal detection output circuit is electrically connected to the voltage comparator circuit and is also electrically connected to the loop control module.

3. A novel wireless transmitter source switching system according to claim 2, characterized in that: The voltage follower circuit and the inverting voltage amplifier circuit are integrated into a set of LM324 chips, and the voltage comparator circuit is implemented using another set of LM324 chips.

4. A novel wireless transmitter source switching system according to claim 2, characterized in that: The signal detection output circuit is connected to a fault indication circuit upon power-up.

5. A novel wireless transmitter source switching system according to claim 1, characterized in that: The loop control module includes a loop control core chip, a first logic comparison circuit, a second logic comparison circuit, an audio detection module, a working indicator circuit, and a switch circuit. The first logic comparison circuit is electrically connected to the loop control core chip, the second logic comparison circuit is electrically connected to the loop control core chip, the audio detection module is electrically connected to the second logic comparison circuit, the working indicator circuit is electrically connected to the loop control core chip, and the switch is electrically connected to the loop control core chip.

6. A novel wireless transmitter source switching system according to claim 5, characterized in that: The first logical comparison is equipped with a manual switching and reset button.

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