Frequency converter current sampling resistor convenient combination circuit

Abstract

The utility model discloses a frequency converter current sampling resistor convenient combination circuit comprising a current sensor connected with a frequency converter and used for collecting output current of the frequency converter, and the current sensor is connected with a current sampling unit and used for outputting actual output current of the frequency converter collected by the current sensor. The current sampling unit is connected with the current conversion signal unit and is used for amplifying and converting actual output current of the frequency converter into signals identified by the CPU and transmitting the signals to the CPU through the current signal output interface; the current sampling unit comprises four sampling resistors connected in parallel and a dial switch, pins 5, 6, 7 and 8 of the dial switch are grounded, and pins 1, 2, 3 and 4 of the dial switch are respectively connected with the four sampling resistors. In actual use, the production efficiency of frequency converter manufacturers is greatly improved, the probability of wrong welding and missing welding of the circuit board is effectively reduced, meanwhile, the universality of the circuit board is improved, and certain cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of inverter current sampling, in particular to a circuit of a convenient combination of inverter current sampling resistors. Background Art

[0002] A frequency converter is a power conditioner that converts the voltage and frequency of an AC power source into the power required by a motor, controlling the motor's operating speed. Its basic principle is to input AC power into the inverter, which then uses internal circuitry to convert the voltage and frequency of the AC power source into the power required by the motor. The motor's speed can then be adjusted by controlling the inverter's output frequency.

[0003] Current is a crucial parameter for inverters controlling motor speed and output power, so accurate current data must be obtained through current sampling circuits. Current sampling enables functions such as current limiting, undervoltage protection, and overload protection, while also enabling motor load diagnosis and fault detection. Inverters of varying power require different resistor values ​​in the current sampling circuit. During the inverter production process, manufacturers must solder corresponding sampling resistors onto the circuit board based on power requirements. This is a time-consuming and labor-intensive process, and is prone to soldering errors and missed connections, leading to rework.

[0004] Figure 1 This is the current sampling circuit for a 45kW inverter. R260 and R262 are sampling resistors. Their operating principle is that a current sensor collects the actual output current of the inverter. The signal generated by the sensor is then passed through an operational amplifier circuit to generate a signal that the CPU can interpret. While this sampling circuit has a simple structure, the values ​​of the sampling resistors R260 and R262 must be adjusted according to the inverter power, making it inconvenient. Utility Model Content

[0005] In order to solve the problems of complicated installation of the transmission mechanism for opening and closing the doors of the above-mentioned existing gun and ammunition cabinets, large friction due to obstruction of the contact surface, complicated installation, inflexible use and high cost, the utility model provides a circuit with a convenient combination of an inverter current sampling resistor.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A circuit for conveniently combining inverter current sampling resistors includes a current sensor connected to the inverter for collecting the inverter's output current, the current sensor connected to a current sampling unit for outputting the actual output current of the inverter collected by the current sensor, the current sampling unit connected to a current conversion signal unit for amplifying the actual output current of the inverter, converting it into a signal recognizable by a CPU, and transmitting it to the CPU via a current signal output interface; the current sampling unit includes four parallel-connected sampling resistors and a dip switch, wherein pins 5, 6, 7, and 8 of the dip switch are grounded, and pins 1, 2, 3, and 4 are respectively connected to the four sampling resistors.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: in actual use, the present invention greatly improves the production efficiency of inverter manufacturers, effectively reduces the probability of incorrect soldering and missed soldering of circuit boards, and at the same time improves the versatility of circuit boards, saving a certain amount of cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is the schematic diagram of the current sampling circuit of the existing inverter;

[0010] Figure 2 This is a schematic diagram of the current sampling circuit of the inverter provided by an embodiment of the utility model.

[0011] In the figure: 1. current sampling unit, 101. sampling resistor, 102. dip switch, 2. current sensor, 3. current conversion signal unit, 4. current signal output interface. DETAILED DESCRIPTION

[0012] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0013] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0014] like Figure 2As shown, the embodiment of the present utility model includes a current sensor 2 connected to the inverter, which is used to collect the output current of the inverter. The current sensor 2 is connected to the current sampling unit 1, which is used to output the actual output current of the inverter collected by the current sensor 2. The current sampling unit 1 is connected to the current conversion signal unit 3, which is used to amplify the actual output current of the inverter and convert it into a signal that can be recognized by the CPU, and transmit it to the CPU through the current signal output interface 4; the current sampling unit 1 includes four parallel sampling resistors 101 and a dip switch 102, the 5th, 6th, 7th, and 8th pins of the dip switch 102 are grounded, and the 1st, 2nd, 3rd, and 4th pins are respectively connected to the four sampling resistors 101.

[0015] like Figure 1 The figure shows the current sampling circuit of an existing 45KW inverter. R260 and R262 are sampling resistors 101. Its working principle is that the current sensor 2 collects the actual output current of the inverter, and the signal it sends is converted into a signal that can be recognized by the CPU through the current signal conversion unit 3. This sampling circuit has a simple structure. The sampling resistors R260 and R262 need to adjust the resistance value according to the different power of the inverter, which is not convenient enough.

[0016] like Figure 2 The figure shows the current sampling circuit of the inverter provided by this embodiment, wherein the sampling resistors R259-R262 are respectively connected to GND through the dip switches 102. By simply adjusting the dip switches, the current sampling resistor values ​​required by the five different power inverters of 45KW-110KW can be combined, which is very convenient. The combination is as follows:

[0017]

[0018] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A circuit for conveniently combining a current sampling resistor with an inverter, comprising a current sensor connected to the inverter for collecting the inverter's output current; the current sensor connected to a current sampling unit for outputting the actual output current of the inverter; and the current sampling unit connected to a current signal conversion unit for amplifying the actual output current of the inverter, converting it into a signal recognizable by a CPU, and transmitting the signal to the CPU via a current signal output interface. Characterized by: The current sampling unit includes four parallel sampling resistors and a dip switch, wherein pins 5, 6, 7, and 8 of the dip switch are grounded, and pins 1, 2, 3, and 4 are connected to the four sampling resistors respectively.

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