Intrinsic safety power supply protection circuit for mining dust fall spraying

Abstract

The utility model belongs to the field of intrinsically safe power supplies, and relates to an intrinsically safe power supply protection circuit for mining dust-fall spraying, which can maintain the stability of instantaneous voltage and current of a load and prevent electric sparks from being generated in the running process of the load. According to the technical scheme, the protection circuit comprises an overcurrent protection circuit, an overvoltage protection circuit, a first spark-proof protection circuit and a second spark-proof protection circuit. And the overvoltage protection circuit is electrically connected with the overcurrent protection circuit. The first spark-proof protection circuit is connected with the load in parallel, and the first spark-proof protection circuit is configured to be that when the voltage of the input end of the load exceeds a voltage threshold value, a capacitor of the first spark-proof protection circuit is connected with the two ends of the load in parallel. The coil of the second spark-proof protection circuit is connected in series between the overcurrent protection circuit and the load, and the second spark-proof protection circuit is configured in a way that when the current of one end, electrically connected with the overcurrent protection circuit, of the coil exceeds a current threshold value, a shunt circuit, connected in parallel with the load, in the second spark-proof protection circuit is conducted.

Description

Technical Field

[0001] This utility model belongs to the field of intrinsically safe power supplies and relates to an intrinsically safe power supply protection circuit for dust suppression spraying in mining. Background Technology

[0002] Mining dust suppression spray systems require the opening and closing of control valves on pipelines, involving the acquisition of signals from various types of sensors and data processing by microprocessors. To ensure safe operation of the mining dust suppression spray system underground, intrinsically safe power supply is required.

[0003] Intrinsically safe power supplies can provide timely control in case of overcurrent or overvoltage, avoiding obvious electrical sparks during load operation. In other words, intrinsically safe power supplies ensure the safe and reliable operation of control valves, sensors, and microprocessors in mining dust suppression spray systems.

[0004] In current technology, overcurrent protection circuits or overvoltage protection circuits may collect the current or voltage values ​​in the main circuit. When the threshold is exceeded, the overcurrent protection circuit or overvoltage protection circuit will disconnect the circuit. However, the operation of overcurrent protection circuits or overvoltage protection circuits often takes time, and a sudden power outage of the load may still cause electrical sparks due to sudden changes in voltage and current in the circuit. Utility Model Content

[0005] To overcome the deficiencies in the aforementioned related technologies, this utility model proposes an intrinsically safe power supply protection circuit for dust suppression spraying in mines, which has the function of maintaining the stability of instantaneous voltage and current of the load and avoiding the generation of electric sparks during the operation of the load.

[0006] To achieve the above technical objectives, this utility model provides an intrinsically safe power supply protection circuit for mining dust suppression spraying. The intrinsically safe power supply protection circuit for mining dust suppression spraying includes: an overcurrent protection circuit, an overvoltage protection circuit, a first spark protection circuit, and a second spark protection circuit. The overcurrent protection circuit is electrically connected to the positive terminal of the power supply. The overvoltage protection circuit is electrically connected to the overcurrent protection circuit. The first spark protection circuit is connected in parallel with the load and is configured to: detect the voltage at the input terminal of the load; when the voltage at the input terminal of the load exceeds a voltage threshold, the capacitor of the first spark protection circuit is connected in parallel with both ends of the load. The coil of the second spark protection circuit is connected in series between the overcurrent protection circuit and the load. The second spark protection circuit is configured to: detect the current at the end of the coil electrically connected to the overcurrent protection circuit; when the current at the end of the coil electrically connected to the overcurrent protection circuit exceeds a current threshold, the shunt circuit in the second spark protection circuit connected in parallel with the load is activated.

[0007] Preferably, the first spark protection circuit includes: a first thyristor, a driving circuit, and a discharge circuit. The first thyristor is connected in series with the capacitor, and the series-connected first thyristor and the capacitor are connected in parallel with the load. One end of the driving circuit is electrically connected to the input terminal of the load, and the other end of the driving circuit is electrically connected to the control electrode of the first thyristor. The driving circuit is configured to detect the voltage at the input terminal of the load, and when the voltage at the input terminal of the load exceeds a threshold voltage, control the first thyristor to conduct. The discharge circuit is connected in parallel with the two ends of the capacitor, and the discharge circuit is configured to discharge the capacitor when the first thyristor is turned off.

[0008] Preferably, the driving circuit includes an avalanche diode and a third resistor, wherein the cathode of the avalanche diode is electrically connected to the load input terminal, the anode of the avalanche diode is connected in series with the third resistor, and the third resistor is electrically connected to the control electrode of the first thyristor.

[0009] Preferably, the discharge circuit includes: a first resistor and a second resistor, the first resistor and the second resistor being connected in series, one end of the first resistor being electrically connected to the anode of the first thyristor, one end of the second resistor being electrically connected to one end of the capacitor, and the connection end of the first resistor and the second resistor being electrically connected to the connection end of the cathode of the first thyristor and the other end of the capacitor.

[0010] Preferably, the discharge circuit includes a Zener diode, which is connected in parallel to a first resistor and a second resistor connected in series.

[0011] Preferably, the second spark protection circuit includes a second thyristor, a coil, and a fourth resistor. Preferably, the anode of the second thyristor is connected to the other end of the coil, and the cathode of the second thyristor is connected to the connection point of the shunt protection circuit composed of the second resistor and capacitor.

[0012] Preferably, the shunt circuit includes a shunt resistor, i.e., a second resistor, the cathode of the second thyristor is electrically connected to one end of the shunt resistor, and the other end of the shunt resistor is electrically connected to the output terminal of the load.

[0013] Preferably, the shunt circuit includes a second resistor. The second resistor serves both as a discharge resistor in the first spark protection circuit and as a shunt resistor in the second spark protection circuit.

[0014] The beneficial effects of this utility model are as follows:

[0015] This invention employs a first anti-spark protection circuit. When a sudden increase in voltage is detected at the load input terminal, the circuit of the capacitor connected in parallel with the load can be turned on, the capacitor is charged to reduce the voltage at the load input terminal, thus preventing the load from generating electric sparks due to a sudden increase in voltage. It also provides sufficient time for the overvoltage protection circuit to operate, further improving the power supply safety of the intrinsically safe power supply.

[0016] This invention employs a second anti-spark protection circuit with a coil, which can prevent sudden current from directly entering the load. The coil provides sufficient reaction time for the second thyristor, enabling the shunt circuit to conduct and divert excessive current, thus ensuring the stability of the current passing through the load. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is the circuit diagram of this utility model. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] like Figure 1 As shown, some embodiments of this utility model provide an intrinsically safe power supply protection circuit for a dust suppression sprayer in mining. The intrinsically safe power supply protection circuit for a dust suppression sprayer in mining includes: an overcurrent protection circuit 1, an overvoltage protection circuit 2, a first spark protection circuit, and a second spark protection circuit. The overcurrent protection circuit 1 is electrically connected to the positive terminal of the power supply. The overvoltage protection circuit 2 is electrically connected to the overcurrent protection circuit 1. The first spark protection circuit is connected in parallel with a load 3, and is configured to: detect the voltage at the input terminal of the load 3; when the voltage at the input terminal of the load 3 exceeds a voltage threshold, the capacitor C of the first spark protection circuit is connected in parallel with the two ends of the load 3. The coil M of the second spark protection circuit is connected in series between the overcurrent protection circuit 1 and the load 3. The second spark protection circuit is configured to detect the current at one end of the coil M that is electrically connected to the overcurrent protection circuit 1. When the current at one end of the coil M that is electrically connected to the overcurrent protection circuit 1 exceeds the current threshold, the shunt circuit in the second spark protection circuit that is connected in parallel with the load 3 is turned on.

[0023] The load's output terminal is electrically connected to the negative terminal of the power supply, wherein the power supply outputs DC power and the power supply's output voltage does not exceed 24V.

[0024] In some embodiments, the first spark protection circuit includes: a first silicon controlled rectifier (SCR) 1, a driving circuit, and a discharge circuit. The first SCR 1 is connected in series with the capacitor C, and the series-connected first SCR 1 and the capacitor C are connected in parallel with the load 3. One end of the driving circuit is electrically connected to the input terminal of the load 3, and the other end of the driving circuit is electrically connected to the control electrode of the first SCR 1. The driving circuit is configured to detect the voltage at the input terminal of the load 3, and when the voltage at the input terminal of the load 3 exceeds a threshold voltage, control the first SCR 1 to conduct. The discharge circuit is connected in parallel with the two ends of the capacitor C, and the discharge circuit is configured to discharge the capacitor C when the first SCR 1 is turned off.

[0025] In some embodiments, the driving circuit includes an avalanche diode V and a third resistor R3. The cathode of the avalanche diode V is electrically connected to the input terminal of the load 3, the anode of the avalanche diode V is connected in series with the third resistor R3, and the third resistor R3 is electrically connected to the control electrode of the first thyristor SCR1.

[0026] In some embodiments, the discharge circuit includes: a first resistor R1 and a second resistor R2, the first resistor R1 and the second resistor R2 are connected in series, one end of the first resistor R1 is electrically connected to the anode of the first silicon controlled rectifier SCR1, one end of the second resistor R2 is electrically connected to one end of the capacitor C, and the connection end of the first resistor R1 and the second resistor R2 is also electrically connected to the connection end of the cathode of the first silicon controlled rectifier SCR1 and the other end of the capacitor C.

[0027] The resistance of the first resistor R1 is relatively large, meaning that the current flowing through resistors R1 and R2 is small and can be ignored.

[0028] In some embodiments, the discharge circuit includes a Zener diode D, which is connected in parallel to a first resistor R1 and a second resistor R2 connected in series.

[0029] In some embodiments, the second spark protection circuit further includes a second silicon controlled rectifier (SCR2), the control electrode of the second SCR2 is connected to the connection point of the coil M and the overcurrent protection circuit 1, the anode of the second SCR2 is connected to the other end of the coil M, and the cathode of the second SCR2 is electrically connected to the shunt circuit.

[0030] A protective resistor can be connected in series on the line between the control electrode of the second thyristor SCR2 and the coil M. The protective resistor R4 can prevent the second thyristor SCR2 from being damaged by excessive current, or facilitate the selection of the second thyristor SCR2.

[0031] In some embodiments, the discharge circuit includes a second resistor R2. The second resistor R2 serves both a shunt and a discharge function.

[0032] The specific operation process of this utility model is as follows:

[0033] When a short circuit occurs in load 3, the current in the main circuit suddenly increases. The overcurrent protection circuit 1 detects this surge and cuts off the main circuit. However, the instantaneous current through load 3 is already excessive. The sudden current is delayed by coil M. Simultaneously, the control electrode of the second thyristor SCR2 conducts when the current exceeds the rated current of load 3, meaning the shunt circuit is activated. The sudden current, after passing through coil M, flows to the negative terminal of the power supply via the shunt circuit and load 3. It can be understood that the shunt circuit reduces the current flowing to load 3, ensuring safety momentarily after a short circuit and preventing electrical sparks due to excessive current.

[0034] When the voltage of the main circuit increases, the drive circuit detects that the voltage at the input terminal of load 3 is higher than the rated voltage, that is, the avalanche diode V breaks down in reverse. At this time, the first thyristor SCR1 is turned on to charge the capacitor C, which can reduce the voltage that suddenly rises across load 3 or slow down the voltage rise trend across load 3, and prevent load 3 from generating electric sparks due to sudden voltage increase.

[0035] In addition, when the circuit voltage drops, the first thyristor SCR1 turns off, and the second resistor R2 releases the charge stored in capacitor C, providing a prerequisite for subsequent stable operation.

[0036] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0037] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An intrinsically safe power supply protection circuit for dust suppression spraying in mining, characterized in that, include: An overcurrent protection circuit is electrically connected to the positive terminal of the power supply. An overvoltage protection circuit, which is electrically connected to the overcurrent protection circuit; A first spark protection circuit is connected in parallel with the load. The first spark protection circuit is configured to detect the voltage at the input terminal of the load. When the voltage at the input terminal of the load exceeds a voltage threshold, the capacitor of the first spark protection circuit is connected in parallel with the two ends of the load. The second spark protection circuit has its coil connected in series between the overcurrent protection circuit and the load. The second spark protection circuit is configured to detect the current at one end of the coil that is electrically connected to the overcurrent protection circuit. When the current at one end of the coil that is electrically connected to the overcurrent protection circuit exceeds the current threshold, the shunt circuit in the second spark protection circuit that is connected in parallel with the load is turned on.

2. The intrinsically safe power supply protection circuit for mine dust suppression spraying according to claim 1, characterized in that, The first spark protection circuit includes: A first thyristor, the first thyristor being connected in series with the capacitor, and the series-connected first thyristor and the capacitor being connected in parallel with the load; A driving circuit, one end of which is electrically connected to the load input terminal and the other end of which is electrically connected to the control electrode of the first thyristor, is configured to detect the voltage at the load input terminal and control the first thyristor to conduct when the voltage at the load input terminal exceeds a threshold voltage. A discharge circuit is connected in parallel with the two ends of the capacitor, and the discharge circuit is configured to discharge the capacitor when the first thyristor is turned off.

3. The intrinsically safe power supply protection circuit for mine dust suppression spraying according to claim 2, characterized in that, The driving circuit includes an avalanche diode and a third resistor. The cathode of the avalanche diode is electrically connected to the load input terminal, the anode of the avalanche diode is connected in series with the third resistor, and the third resistor is electrically connected to the control electrode of the first thyristor.

4. The intrinsically safe power supply protection circuit for mine dust suppression spraying according to claim 3, characterized in that, The discharge circuit includes a first resistor and a second resistor, the first resistor and the second resistor are connected in series, one end of the first resistor is electrically connected to the anode of the first thyristor, one end of the second resistor is electrically connected to one end of the capacitor, and the connection end of the first resistor and the second resistor is also electrically connected to the connection end of the cathode of the first thyristor and the other end of the capacitor.

5. The intrinsically safe power supply protection circuit for mine dust suppression spraying according to claim 4, characterized in that, The discharge circuit includes a Zener diode, which is connected in parallel to a first resistor and a second resistor connected in series.

6. The intrinsically safe power supply protection circuit for mine dust suppression spraying according to any one of claims 1 to 5, characterized in that, The second spark protection circuit also includes a second thyristor. The control electrode of the second thyristor is connected to the connection point of the coil and the overcurrent protection circuit. The anode of the second thyristor is connected to the other end of the coil. The cathode of the second thyristor is electrically connected to the shunt circuit.

7. The intrinsically safe power supply protection circuit for mine dust suppression spraying according to claim 6, characterized in that, The shunt circuit includes a shunt resistor R2, the cathode of the second thyristor is electrically connected to one end of the shunt resistor R2, and the other end of the shunt resistor is electrically connected to the input terminal of the load.

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