Frequency converter power supply board input anti-reverse-connection indicating circuit

Abstract

The utility model discloses a frequency converter power supply board input anti-reverse connection indicating circuit, comprising a bus positive pole P + and a bus negative pole P. A voltage division circuit, a voltage stabilizing diode D4 and an MOS tube Q1 are successively connected between the bus positive pole P + and the bus negative pole P-, and a fast recovery diode D2, an alarm circuit and a step-down circuit are successively connected between the bus positive pole P + and the bus negative pole P-. And the cathode of the fast recovery diode D2 is connected with the bus anode P +. According to the utility model, major circuit faults and safety accidents caused by reverse connection of the positive and negative electrodes of the bus can be prevented, sound-light alarm signals can be sent out when the positive and negative electrodes of the bus are connected reversely, assembly personnel are reminded to check wiring and then remove faults, and the universal applicability is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency converters, in particular to an input reverse connection prevention indicating circuit for a power supply board of a frequency converter. Background Art

[0002] The inverter is a power control device that uses frequency conversion technology and microelectronics technology to control AC motors by changing the frequency of the motor's working power supply. The inverter relies on the internal IGBT to adjust the voltage and frequency of the output power supply, and provides the required power supply voltage according to the actual needs of the motor, thereby achieving the purpose of energy saving and speed regulation; in addition, the inverter has many protection functions, such as overcurrent, overvoltage, overload protection, etc. With the continuous improvement of industrial automation, inverters have also been widely used.

[0003] During the assembly process of the inverter, the internal circuit boards, such as the fan power board, often rely on the busbar for power supply, which requires the busbar wiring operation. During the wiring process, whether the positive and negative poles of the busbar are connected correctly not only affects whether the circuit board can work properly, but also affects the safety of subsequent inspections. Once the positive and negative poles of the busbar are connected in reverse, it is very easy for the circuit board to spark and be damaged, and in severe cases, it is easy to cause a short circuit and fire.

[0004] At present, the positive and negative poles of the busbar are distinguished by colors. Usually, the color of the positive pole of the busbar is red, and the color of the negative pole of the busbar is black. The different colors of the positive and negative poles of the busbar are used to avoid the situation where the positive and negative poles of the busbar are connected in reverse. However, not all positive and negative poles of the busbar are given different colors, and when the positive and negative poles of the busbar are wrapped with an insulating layer, it is often difficult to distinguish the colors. Therefore, the above technical means to prevent the positive and negative poles of the busbar from being connected in reverse are not universally applicable. Utility Model Content

[0005] The purpose of the utility model is to overcome the defects and shortcomings of the prior art and to provide an input reverse connection prevention indication circuit for a frequency converter power supply board, which can prevent major circuit failures and safety accidents caused by reverse connection of the positive and negative poles of the busbar, and can send out sound and light alarm signals when the positive and negative poles of the busbar are reversed to remind assemblers to check the wiring and then eliminate the fault, and the utility model has universal applicability.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A frequency converter power supply board input reverse connection prevention indication circuit includes a bus positive pole P+ and a bus negative pole P-, and is characterized in that: a voltage divider circuit, a voltage stabilizing diode D4 and a MOS tube Q1 are sequentially connected between the bus positive pole P+ and the bus negative pole P- on the one hand, and a fast recovery diode D2, an alarm circuit and a step-down circuit are sequentially connected on the other hand, and the cathode of the fast recovery diode D2 is connected to the bus positive pole P+.

[0008] Furthermore, the voltage divider circuit includes resistors R7, R8, R9, and R10. After the resistors R7, R8, and R9 are connected in series, one end is connected to the bus positive electrode P+, ​​and the other end is connected to the gate of the MOS tube Q1. The resistor R10 is connected between the gate of the MOS tube Q1 and the ground KGND.

[0009] Furthermore, the source of the MOS tube Q1 is connected to the negative electrode P- of the busbar, and the drain of the MOS tube Q1 is connected to the ground KGND.

[0010] Furthermore, the voltage stabilizing diode D4 is connected between the gate of the MOS transistor Q1 and the ground KGND.

[0011] Furthermore, the alarm circuit includes a voltage stabilizing diode D1, a buzzer BZ1 and an LED indicator light D3 connected in parallel.

[0012] Furthermore, the cathode of the LED indicator D3 is connected to a current limiting resistor R11.

[0013] Furthermore, the step-down circuit includes resistors R1, R2, R3, R4, R5, and R6. The resistor R1 and the resistor R4, the resistor R2 and the resistor R5, and the resistor R3 and the resistor R6 are respectively connected in parallel and then in series.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The utility model adopts MOS tube as the switching device for busbar conduction, which is turned on when the positive and negative poles of the busbar are not reversed, and then the busbar is turned on to supply power to the internal circuit board of the inverter. It is cut off when the positive and negative poles of the busbar are reversed, and then the busbar is disconnected to stop power supply, which can prevent major circuit failures and safety accidents caused by the reverse connection of the positive and negative poles of the busbar. At the same time, a reverse-conducting alarm circuit (mainly composed of an LED lamp and a buzzer) is adopted to send out an audible and visual alarm signal when the positive and negative poles of the busbar are reversed, so as to remind assemblers to check the wiring and then eliminate the fault. The utility model has universal applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a circuit structure schematic diagram of the utility model. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] See also Figure 1 A frequency converter power supply board input reverse connection prevention indication circuit includes a bus positive electrode P+ and a bus negative electrode P-, a voltage divider circuit, a voltage stabilizing diode D4 and a MOS tube Q1 are connected in sequence between the bus positive electrode P+ and the bus negative electrode P- on the one hand, and a fast recovery diode D2, an alarm circuit and a step-down circuit are connected in sequence on the other hand, and the cathode of the fast recovery diode D2 is connected to the bus positive electrode P+.

[0019] In the utility model, the voltage divider circuit includes resistors R7, R8, R9, and R10. After the resistors R7, R8, and R9 are connected in series, one end is connected to the bus positive electrode P+, ​​and the other end is connected to the gate of the MOS tube Q1. The resistor R10 is connected between the gate of the MOS tube Q1 and the ground KGND.

[0020] In the present invention, the source of the MOS tube Q1 is connected to the negative electrode P- of the busbar, and the drain of the MOS tube Q1 is connected to the ground KGND.

[0021] In the present invention, the voltage stabilizing diode D4 is connected between the gate of the MOS tube Q1 and the ground KGND.

[0022] In the utility model, the alarm circuit comprises a voltage-stabilizing diode D1, a buzzer BZ1 and an LED indicator light D3 which are connected in parallel.

[0023] In the present invention, the cathode of the LED indicator D3 is connected to a current limiting resistor R11.

[0024] In the utility model, the step-down circuit includes resistors R1, R2, R3, R4, R5 and R6. The resistors R1 and R4, R2 and R5, and R3 and R6 are respectively connected in parallel and then in series.

[0025] The utility model is further described below in conjunction with the accompanying drawings:

[0026] When the bus positive electrode P+ and the bus negative electrode P- are not connected reversely, the bus positive electrode P+ stabilizes the voltage of the voltage-stabilizing diode (15V) D4 at 15V through the voltage divider circuit composed of resistors R7, R8, R9, and R10, that is, a high level of 15V is generated at the gate (pin 1) of the MOS tube (900V / 4A) Q1, and the MOS tube Q1 is turned on.

[0027] At this time, the negative electrode P- of the busbar and the ground KGND generate the same potential, supplying power to the internal circuit boards of the inverter, such as the fan power board.

[0028] At the same time, since the cathode of the fast recovery diode (1000V / 1A) D2 is connected to the bus positive electrode P+, ​​the alarm circuit is reversely cut off, so the buzzer BZ1 and the light emitting diode D3 will not be turned on.

[0029] When the bus positive electrode P+ and the bus negative electrode P- are connected reversely, that is, the bus positive electrode P+ is connected to the bus negative electrode P-, and the bus negative electrode P- is connected to the bus positive electrode P+. At this time, the bus positive electrode P+ cannot stabilize the voltage of the voltage regulator diode D4 at 15V through the voltage divider circuit composed of resistors R7, R8, R9, and R10. Therefore, the MOS tube Q1 will not be turned on and will not supply power to the internal circuit boards of the inverter, such as the fan power board.

[0030] At the same time, the reversely connected bus positive electrode P+ (actually the bus negative electrode P-) stabilizes the voltage of the voltage-stabilizing diode (5.1V) D1 at 5.1V through a step-down circuit composed of resistors R1, R2, R3, R4, R5, and R6, so that the light-emitting diode D3 and the buzzer BZ1 are turned on, and an audible and visual alarm signal is issued, that is, the light-emitting diode D3 lights up or flashes, and the buzzer BZ1 sounds, reminding the assembler to check the wiring and then eliminate the fault.

[0031] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0032] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. An input reverse connection prevention indication circuit for a frequency converter power supply board, comprising a bus positive electrode P+ and a bus negative electrode P-, characterized in that: On the one hand, a voltage divider circuit, a voltage stabilizing diode D4 and a MOS tube Q1 are connected in sequence between the bus positive electrode P+ and the bus negative electrode P-, and on the other hand, a fast recovery diode D2, an alarm circuit and a step-down circuit are connected in sequence, and the cathode of the fast recovery diode D2 is connected to the bus positive electrode P+.

2. The inverter power supply board input anti-reverse connection indication circuit according to claim 1, characterized in that: The voltage divider circuit includes resistors R7, R8, R9, and R10. After being connected in series, one end of the resistors R7, R8, and R9 is connected to the bus positive electrode P+, ​​and the other end is connected to the gate of the MOS tube Q1. The resistor R10 is connected between the gate of the MOS tube Q1 and the ground KGND.

3. The inverter power supply board input anti-reverse connection indication circuit according to claim 2, characterized in that: The source of the MOS tube Q1 is connected to the negative electrode P- of the busbar, and the drain of the MOS tube Q1 is connected to the ground KGND.

4. The inverter power supply board input anti-reverse connection indication circuit according to claim 3, characterized in that: The voltage stabilizing diode D4 is connected between the gate of the MOS tube Q1 and the ground KGND.

5. The inverter power supply board input anti-reverse connection indication circuit according to claim 1, characterized in that: The alarm circuit comprises a voltage stabilizing diode D1, a buzzer BZ1 and an LED indicator light D3 which are connected in parallel.

6. The inverter power supply board input anti-reverse connection indication circuit according to claim 5, characterized in that: The cathode of the LED indicator light D3 is connected to a current limiting resistor R11.

7. The inverter power supply board input anti-reverse connection indication circuit according to claim 1, characterized in that: The step-down circuit includes resistors R1, R2, R3, R4, R5 and R6. The resistor R1 and the resistor R4, the resistor R2 and the resistor R5, and the resistor R3 and the resistor R6 are respectively connected in parallel and then in series.

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