Fault alarm device for cooling fan of PDM system medium-wave broadcast transmitter

Abstract

The utility model discloses a fault alarm device for a cooling fan of a PDM (pulse width modulation) type medium-wave broadcast transmitter, and belongs to the technical field of PDM type medium-wave broadcast transmitters. Comprising a sampling circuit, a rectification filter circuit, a voltage amplification circuit, a voltage reference circuit, a voltage comparison circuit, a control circuit, an alarm circuit and a power supply circuit, can rapidly and accurately detect the fault of the cooling fan of the PDM system medium-wave broadcast transmitter, improves the timeliness and reliability of fault early warning, and is low in cost and easy to popularize. The system is simple in structure, easy to implement and popularize, suitable for medium wave transmitting stations of various scales, and beneficial for finding and processing problems in time by monitoring the running state of the heat dissipation fan in real time, potential broadcast accidents are avoided, normal running of a transmitter is guaranteed, the risk that the performance of the transmitter is reduced or damaged due to faults of the heat dissipation fan is reduced, and the service life of the transmitter is prolonged. And safe and high-quality broadcasting of broadcast signals is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of PDM medium wave broadcast transmitters, and more specifically to a heat dissipation fan failure alarm device for a PDM medium wave broadcast transmitter. Background Art

[0002] PDM medium wave broadcast transmitter is widely used in medium wave transmitters in my country. It is one of the important equipment to ensure the stable transmission of broadcast signals. During its operation, the power amplifier module will generate a lot of heat. If the heat cannot be dissipated in time and effectively, it will seriously affect the normal operation of the transmitter and may even cause equipment damage. Therefore, the heat dissipation fan plays a vital role in it. It continuously sends air to take away the heat, thereby ensuring the normal operation of the transmitter.

[0003] However, various problems may occur in the actual use of existing cooling fans, among which shutdown failure is a more common one. Once this failure occurs, the cooling effect will drop sharply, and the temperature of the power amplifier module will rise rapidly, posing a serious threat to the transmitter. What is more serious is that many PDM medium wave transmitters lack the automatic alarm function of fan failure, which makes it difficult for staff to detect fan failure in time and take timely measures to deal with it, thus bringing great hidden dangers to the safe broadcasting of medium wave transmitters. Once a problem occurs, it may not only cause the interruption of the broadcast signal and affect the audience's listening experience, but also may have adverse effects on society. Therefore, the development of a device with an automatic alarm function for fan failure is of great significance to ensuring the safe broadcasting of medium wave transmitters.

[0004] Therefore, in view of the above problems, a PDM medium wave broadcast transmitter heat dissipation fan failure alarm device is proposed. Utility Model Content

[0005] 1. Technical problems to be solved

[0006] In view of the problems existing in the prior art, the purpose of the utility model is to provide a PDM medium wave broadcast transmitter cooling fan fault alarm device, which can realize real-time sensing of the operating current of the cooling fan through a current transformer and a sampling circuit, and convert it into a voltage signal. The rectifier and filter circuit rectifies the AC voltage signal into a DC voltage signal, and the voltage amplifier circuit amplifies the sampled voltage.

[0007] 2. Technical solution

[0008] To solve the above problems, the utility model adopts the following technical solutions.

[0009] A PDM medium wave broadcast transmitter heat dissipation fan fault alarm device, comprising a sampling circuit, a rectifier filter circuit, a voltage amplifier circuit, a voltage reference circuit, a voltage comparison circuit, a control circuit, an alarm circuit, a power supply circuit and a freewheeling diode;

[0010] The sampling circuit uses a current transformer to sense the operating current of the cooling fan, and converts it into an AC voltage signal through a sampling resistor. The sampling circuit is connected to a rectifier and filter circuit. The rectifier and filter circuit is used to rectify the AC voltage signal of the sampling circuit into a DC voltage signal, and is connected to a voltage amplifier circuit. The voltage amplifier circuit is connected to a voltage comparison circuit and is used to amplify the voltage signal. The voltage reference circuit is connected to the voltage comparison circuit, and the reference voltage is adjusted by a potentiometer to provide a reference voltage to the control circuit. The comparison circuit is connected to the control circuit and provides a control signal to the control circuit based on the high and low between the sampling voltage and the reference voltage. The control circuit is connected to an alarm circuit and controls the conduction or disconnection of the alarm circuit according to the control element. The freewheeling diode is connected to the control element to protect the control element from being broken down or burned by the induced voltage.

[0011] Furthermore, the power supply circuit is a direct current power supply.

[0012] Furthermore, the current transformer in the sampling circuit is installed on the power supply line of the heat dissipation fan.

[0013] Furthermore, the voltage amplification circuit is implemented using an operational amplifier.

[0014] Furthermore, the voltage reference circuit is implemented by a resistor voltage divider circuit.

[0015] Furthermore, the comparison circuit is implemented by a comparator.

[0016] Furthermore, the alarm circuit is implemented using an audible and visual alarm.

[0017] 3. Beneficial effects

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] (1) This scheme can quickly and accurately detect the fault of the cooling fan of the PDM medium wave broadcast transmitter, thereby improving the timeliness and reliability of fault warning. The device is low-cost, easy to implement and promote, and is suitable for medium wave transmitters of various sizes.

[0020] (2) This solution helps to detect and handle problems in a timely manner by real-time monitoring of the operating status of the cooling fan, thus avoiding potential broadcast accidents, ensuring the normal operation of the transmitter, and reducing the risk of transmitter performance degradation or damage due to cooling fan failure, thereby ensuring the safe and high-quality broadcast of broadcast signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the principle diagram of the fan fault alarm circuit of the utility model;

[0022] Figure 2 This is the installation wiring diagram of the fan fault alarm device of the utility model. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the utility model without making creative work are within the scope of protection of the utility model.

[0024] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0026] Example:

[0027] See also Figure 1 to Figure 2 , a PDM medium wave broadcast transmitter heat dissipation fan fault alarm device, including a sampling circuit, a rectifier filter circuit, a voltage amplifier circuit, a voltage reference circuit, a voltage comparison circuit, a control circuit, an alarm circuit, a power supply circuit and a freewheeling diode;

[0028] The sampling circuit uses a current transformer to sense the operating current of the cooling fan, and converts it into an AC voltage signal through a sampling resistor. The sampling circuit is connected to a rectifier and filter circuit. The rectifier and filter circuit is used to rectify the AC voltage signal of the sampling circuit into a DC voltage signal, and is connected to a voltage amplifier circuit. The voltage amplifier circuit is connected to a voltage comparison circuit and is used to amplify the voltage signal. The voltage reference circuit is connected to the voltage comparison circuit, and the reference voltage is adjusted by a potentiometer to provide a reference voltage to the control circuit. The comparison circuit is connected to the control circuit and provides a control signal to the control circuit based on the high and low between the sampling voltage and the reference voltage. The control circuit is connected to the alarm circuit and controls the conduction or disconnection of the alarm circuit according to the control element. The freewheeling diode is connected to the control element to protect the control element from being broken down or burned by the induced voltage.

[0029] The power supply circuit is a DC power supply;

[0030] This solution uses a stable and reliable DC power supply through the power supply circuit, which can provide continuous and stable power support for the entire device.

[0031] The current transformer in the sampling circuit is installed on the power supply line of the cooling fan;

[0032] This solution precisely installs the current transformer in the sampling circuit on the power supply line of the cooling fan, so that the current changes of the cooling fan can be sensed in real time and accurately, providing a reliable data source for subsequent monitoring and analysis.

[0033] The voltage amplification circuit is implemented using an operational amplifier;

[0034] This solution is implemented by selecting an operational amplifier through a voltage amplification circuit. The operational amplifier has the advantages of high gain, high input impedance and low output impedance, and can effectively amplify the sampled voltage to ensure the quality and stability of the signal.

[0035] The voltage reference circuit is implemented by a resistor voltage divider circuit;

[0036] This solution is implemented by using a resistor voltage divider circuit through a voltage reference circuit. The reference voltage can be adjusted through a potentiometer to provide an accurate reference standard for the comparison circuit, thereby ensuring the accuracy and reliability of the comparison result.

[0037] The comparison circuit is implemented using a comparator;

[0038] This solution is implemented by using a comparator through a comparison circuit. The comparator has the characteristics of high speed and high precision, and can quickly compare the sampling voltage with the reference voltage and output a corresponding control signal.

[0039] The alarm circuit is implemented with an audible and visual alarm;

[0040] In this solution, when a heat dissipation fan fails, the sound and light alarm can promptly emit a loud sound and bright light alarm to remind the staff to take timely measures to avoid further expansion of the failure.

[0041] Working principle: First, the current transformer installed on the power supply line of the cooling fan senses the running current of the fan in real time. When the current passes through the current transformer, an induced current is generated on its secondary winding. This induced current passes through the sampling resistor. Due to the existence of the resistor, the current will produce a voltage drop on the resistor, thereby converting the current into an AC voltage signal;

[0042] Subsequently, the AC voltage signal output by the sampling circuit enters the rectifier filter circuit, in which the AC voltage signal is rectified into a DC voltage signal by a rectifier diode, and the DC voltage signal is further smoothed and stabilized by components such as a filter capacitor, making it a relatively stable DC voltage.

[0043] Next, the rectified and filtered DC voltage signal is input into the voltage amplifier circuit. The voltage amplifier circuit uses devices such as operational amplifiers to amplify the DC voltage signal. By reasonably setting the amplification factor, the DC voltage signal is amplified to a level suitable for subsequent comparison circuits, providing a sampling voltage of sufficient strength for subsequent voltage comparisons.

[0044] In the voltage comparison circuit, the amplified sampled voltage is compared with the reference voltage provided by the voltage reference circuit. The voltage reference circuit usually uses a resistor divider circuit to generate a stable reference voltage. The comparator compares the sampled voltage with the reference voltage bit by bit and outputs different level signals according to the high and low relationship between the two.

[0045] The signal output by the comparison circuit will be transmitted to the control circuit, and the control circuit will generate a corresponding control signal according to the comparison result. When the sampling voltage is higher than the reference voltage, it indicates that the cooling fan may fail, and the control circuit will send a control signal to the alarm circuit to turn it on.

[0046] After receiving the control signal, the alarm circuit will immediately activate the sound and light alarm. The sound and light alarm will emit bright light and sound to remind the staff that the cooling fan has failed and needs to be inspected and maintained in time to ensure the normal operation of the transmitter. Among them, the freewheeling diode is used to protect the control components from being broken down or burned by the induced voltage.

[0047] In this way, the entire device realizes the real-time monitoring and fault alarm functions of the operating status of the cooling fan of the PDM medium wave broadcast transmitter through the coordinated work of various circuit links.

[0048] The above are only preferred specific implementation methods of the utility model; however, the protection scope of the utility model is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the utility model can make equivalent substitutions or changes based on the technical solution and improved ideas of the utility model, which should be included in the protection scope of the utility model.

Claims

1. A PDM medium wave broadcast transmitter cooling fan fault alarm device, characterized in that: It includes a sampling circuit, a rectifier and filter circuit, a voltage amplifier circuit, a voltage reference circuit, a voltage comparison circuit, a control circuit, an alarm circuit, a power supply circuit and a freewheeling diode; The sampling circuit uses a current transformer to sense the operating current of the cooling fan, and converts it into an AC voltage signal through a sampling resistor. The sampling circuit is connected to a rectifier and filter circuit. The rectifier and filter circuit is used to rectify the AC voltage signal of the sampling circuit into a DC voltage signal, and is connected to a voltage amplifier circuit. The voltage amplifier circuit is connected to a voltage comparison circuit and is used to amplify the voltage signal. The voltage reference circuit is connected to the voltage comparison circuit and adjusts the reference voltage through a potentiometer to provide a reference voltage to the control circuit. The comparison circuit is connected to the control circuit and provides a control signal to the control circuit based on the high and low between the sampling voltage and the reference voltage. The control circuit is connected to an alarm circuit and controls the conduction or disconnection of the alarm circuit according to the control element. The freewheeling diode is connected to the control element to protect the control element from being broken down or burned by the induced voltage.

2. A PDM medium wave broadcast transmitter heat dissipation fan failure alarm device according to claim 1, characterized in that: The power supply circuit is a direct current power supply.

3. A PDM medium wave broadcast transmitter heat dissipation fan failure alarm device according to claim 1, characterized in that: The current transformer in the sampling circuit is installed on the power supply line of the heat dissipation fan.

4. A PDM medium wave broadcast transmitter heat dissipation fan failure alarm device according to claim 1, characterized in that: The voltage amplification circuit is implemented by an operational amplifier.

5. A PDM medium wave broadcast transmitter heat dissipation fan failure alarm device according to claim 1, characterized in that: The voltage reference circuit is implemented by a resistor voltage divider circuit.

6. A PDM medium wave broadcast transmitter heat dissipation fan failure alarm device according to claim 1, characterized in that: The comparison circuit is implemented by a comparator.

7. A PDM medium wave broadcast transmitter heat dissipation fan failure alarm device according to claim 1, characterized in that: The alarm circuit is implemented by an audible and visual alarm.

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