CN203084128U - Portable intelligent direct-current electronic load device - Google Patents

Abstract

The utility model relates to a portable intelligent DC electronic load device, comprising a central processing unit, a display unit, a key unit, a PI adjustment unit, a MOSFET drive unit, a communication unit and a power supply unit, a display unit, a key unit, a communication unit and a PI adjustment unit They are respectively connected to the central processing unit, the output terminal of the PI adjustment unit is connected to the control terminal of the MOSFET drive unit, the output terminal of the MOSFET drive unit is connected to the electronic equipment to be tested, the MOSFET drive unit is provided with a voltage and current sampling circuit, and the voltage and current sampling circuit The output end is not only connected with the input end of the PI adjustment unit, but also connected with the central processing unit. The utility model can realize constant voltage, constant current, constant resistance and constant power working modes by controlling the PI adjustment unit through the button unit or the upper computer, thereby meeting the various requirements of the electronic equipment under test.

Description

Portable Smart DC Electronic Load Device

technical field

The utility model relates to a load device, in particular to a portable intelligent DC electronic load device.

Background technique

In the field of electronic technology applications, it is often necessary to test electronic equipment such as switching power supplies, linear power supplies, UPS power supplies, transformers, batteries or chargers. Traditional test methods generally use resistors, sliding wire rheostats, and resistance boxes as test loads. , but these loads cannot meet our various requirements for loads, such as: constant current loads, loads with output interfaces, loads that can be adjusted at will, loads with constant power, dynamic loads, loads with multiple output ports, etc. It is a reliable, comprehensive, simple and quick test of the output characteristics of some electronic equipment.

Contents of the invention

The utility model mainly solves the technical problem that the original use of resistors, sliding wire rheostats or resistance boxes as electronic equipment test loads cannot perform reliable, comprehensive, simple and fast tests on the output characteristics of some electronic equipment; it provides a portable intelligent DC The electronic load device can work in the set mode and the set parameter state, realize the constant voltage, constant current, constant resistance and constant power working mode, and can perform reliable, comprehensive and simple output characteristics of some electronic equipment , Fast test.

The above-mentioned technical problems of the utility model are mainly solved by the following technical solutions: the utility model includes a central processing unit, a display unit, a key unit, a PI adjustment unit, a MOSFET drive unit and provides work for the entire portable intelligent DC electronic load device. The power supply unit of the voltage, the display unit, the button unit and the PI adjustment unit are respectively connected to the central processing unit, the output terminal of the PI adjustment unit is connected to the control terminal of the MOSFET drive unit, and the output terminal of the MOSFET drive unit is connected to the electronic device to be tested The MOSFET driving unit is provided with a voltage and current sampling circuit, and the output terminal of the voltage and current sampling circuit is not only connected with the input terminal of the PI adjustment unit, but also connected with the central processing unit. The central processing unit receives and processes the commands and data set by the key unit, outputs the set value of voltage and current to the PI adjustment unit, the voltage and current sampling circuit collects the voltage and current on the MOSFET drive circuit in real time, and the measured value of the voltage and current is also sent to the PI At the same time, the measured value of the voltage and current is processed by the central processing unit and then sent to the display unit for display. The PI adjustment unit compares the set value with the measured value, and the output signal controls the conduction and cut-off of the MOSFET tube in the MOSFET drive unit, so that the electronic load The device is working in setting mode. Through the control of the PI adjustment unit, the constant voltage, constant current, constant resistance and constant power working modes can be realized, and the output characteristics of some electronic equipment can be tested reliably, comprehensively, simply and quickly.

Preferably, a D/A conversion unit is connected between the central processing unit and the PI adjustment unit, the input end of the D/A conversion unit is connected to the central processing unit, and the output of the D/A conversion unit terminal is connected to the standard voltage input terminal of the PI adjustment unit. The D/A conversion unit converts the set value output by the central processing unit, and then sends it to the PI adjustment unit.

Preferably, an A/D conversion unit is connected between the central processing unit and the output end of the voltage and current sampling circuit, and the input end of the A/D conversion unit is connected to the voltage sampling circuit and the current sampling circuit. The output ends are connected, and the output ends of the A/D conversion unit are connected with the central processing unit. The voltage and current values collected by the voltage and current sampling circuit are converted by the A/D conversion unit and then sent to the central processing unit.

Preferably, the portable intelligent DC electronic load device includes a communication unit, the central processing unit is connected to the communication unit, and the communication unit is connected to the host computer. Through the communication unit, the electronic load device can receive the commands and data sent by the host computer, and work in the working mode set by the host computer according to the notification of the host computer, which is more convenient and flexible to use.

Preferably, the communication unit is a serial port to USB interface unit, the serial port is connected to the central processing unit, and the USB interface is connected to the host computer. The communication connection is convenient, and the rechargeable lithium battery can also be charged through this USB interface.

Preferably, the MOSFET driving unit is connected with an overvoltage and overcurrent protection circuit. Work is safer and more reliable.

Preferably, the display unit and the key unit use liquid crystal touch screens. Compact structure, easy operation and clear display.

As a preference, the central processing unit adopts MSP430F149 single-chip microcomputer. The implementation is convenient and the performance is more reliable.

Preferably, the power supply unit is powered by a rechargeable lithium battery. Easy to carry.

The beneficial effect of the utility model is: it can work in the set mode and the set parameter state according to the key unit setting or the control command sent by the upper computer, and the constant voltage, constant current, constant resistance and constant voltage can be realized through the PI adjustment unit. Constant power working mode, so as to meet the various requirements of the electronic equipment under test, and conduct reliable, comprehensive, simple and fast testing of the output characteristics of the electronic equipment.

Description of drawings

Fig. 1 is a block diagram of circuit principle connection structure of the utility model.

In the figure 1. Central processing unit, 2. Display unit, 3. Button unit, 4. PI adjustment unit, 5. MOSFET drive unit, 6. Power supply unit, 7. Voltage and current sampling circuit, 8. D/A conversion unit, 9. A/D conversion unit, 10. Communication unit, 11. Overvoltage and overcurrent protection circuit, 20. Electronic equipment to be tested, 21. Host computer.

Detailed ways

The technical solutions of the present utility model will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Embodiment: The portable intelligent DC electronic load device of this embodiment, as shown in FIG. Unit 4, MOSFET drive unit 5, communication unit 10, and power supply unit 6 that provides working voltage for the entire portable intelligent DC electronic load device. The display unit 2, the key unit 3 and the communication unit 10 are respectively connected to the central processing unit 1. In this embodiment, the display unit 2 and the key unit 3 are realized by using a liquid crystal touch screen, and the communication unit 10 adopts a serial port to USB interface unit, and the serial port and the central processing unit The unit 1 is connected, and the USB interface is connected with the host computer 21 . The input end of the D/A conversion unit 8 is connected with the central processing unit 1, the output end of the D/A conversion unit 8 is connected with the standard voltage input end of the PI adjustment unit 4, and the output end of the PI adjustment unit 4 is connected with the MOSFET drive unit 5. The control terminal is connected, and the output terminal of the MOSFET drive unit 5 is connected with the electronic device 20 to be tested. The MOSFET drive unit 5 is connected with a voltage and current sampling circuit 7 and an overvoltage and overcurrent protection circuit 11, and the output terminal of the voltage and current sampling circuit 7 is connected with the The input end of the PI adjustment unit 4 is connected to the input end of the A/D conversion unit 9 , and the output end of the A/D conversion unit 9 is connected to the central processing unit 1 . In this embodiment, the central processing unit 1 adopts an MSP430F149 single-chip microcomputer, and the single-chip microcomputer realizes software overcurrent protection, battery voltage detection and overvoltage and overcurrent alarm functions through port configuration. D/A conversion unit 8 adopts 12-bit high-precision fast dual-port D/A converter with TLV5618 serial input, and A/D conversion unit 9 adopts TLV2542A/D conversion chip. The power supply unit 6 is powered by a rechargeable lithium battery, boosted to 8V by a SEPIC circuit composed of a CS5171 boost regulator, and then converted to ±5V and +3.3V required by the electronic load device by using three LM2596-ADJ regulator tubes. Using TP4054 linear lithium-ion battery charging chip, the charging voltage is taken from the USB interface. The TP4054 chip is a single-cell lithium-ion battery charger with a constant current/constant voltage algorithm. It can provide a charging current of 800mA and an internal P-channel power MOSFET tube and thermal regulation circuit without isolation diodes or external current detection resistors. device.

The PI adjustment unit is a linear controller, which forms the control deviation according to the given value and the actual value, and forms the control quantity through linear combination of the proportion and integral of the deviation, and controls the controlled object. The core essence of the electronic load device is a negative feedback control loop composed of a voltage and current sampling PI adjustment unit, which is also the power control circuit of the electronic load device. The MOSFET tube is used here as both the current control device and the load of the power supply under test. In the constant current, constant resistance, constant power mode, the PI adjustment unit compares the voltage drop on the current sampling resistor in the voltage and current sampling circuit with the voltage setting value given by the D/A conversion unit controlled by the microcontroller, and controls the MOSFET The MOSFET tube in the drive unit is turned on and off, so as to achieve the purpose of keeping the current constant. In the constant voltage mode, the PI adjustment unit compares the voltage drop on the voltage sampling resistor in the voltage and current sampling circuit with the voltage setting value given by the D/A conversion unit controlled by the microcontroller to achieve the purpose of system constant voltage.

Working process: the single-chip microcomputer waits for the setting information of the LCD touch screen or the command and data sent by the upper computer and processes it, starts the D/A conversion unit to generate the voltage setting value, starts the A/D conversion unit to sample and drop it on the MOSFET drive circuit in real time The voltage of the sampled data is processed in real time and sent to the LCD touch screen for real-time display or sent to the host computer. For example: when the user selects the constant current working mode and requires the set current to be 2.000A, the voltage on the sampling resistor should be 0.5V through the calculation of the single-chip microcomputer, and the single-chip microcomputer starts the D/A conversion unit to generate a setting of 0.5V The voltage value is given to the PI adjustment unit, and the PI adjustment unit compares the set value with the actual value. The output of the PI adjustment unit controls the MOSFET drive circuit to work in the constant current mode, and maintains the current of the electronic load device within the adjustable range of the input voltage. 2.000A.

The utility model can work in the set mode and the set parameter state according to the key unit setting or the control command sent by the upper computer, and realizes the constant voltage, constant current, constant resistance and constant power working mode through the PI adjustment unit. Therefore, various requirements of the electronic equipment under test can be met, and the output characteristics of the electronic equipment can be tested reliably, comprehensively, simply and quickly.

The above-described embodiment is only a preferred solution of the utility model, and does not limit the utility model in any form. There are other variations and modifications under the premise of not exceeding the technical solution described in the claims. .

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (9)

1. portable intelligent DC electronic load device, it is characterized in that comprising CPU (central processing unit) (1), display unit (2), push-button unit (3), PI regulon (4), MOSFET driver element (5) and the power supply unit (6) that operating voltage is provided for whole portable intelligent DC electronic load device, display unit (2), push-button unit (3) links to each other with described CPU (central processing unit) (1) respectively with PI regulon (4), the output terminal of PI regulon (4) links to each other with the control end of MOSFET driver element (5), the output terminal of MOSFET driver element (5) links to each other with electronic equipment to be measured (20), MOSFET driver element (5) is provided with electric current and voltage sample circuit (7), the output terminal of electric current and voltage sample circuit (7) both linked to each other with the input end of PI regulon (4), linked to each other with described CPU (central processing unit) (1) again.

2. portable intelligent DC electronic load device according to claim 1, it is characterized in that being connected with D/A converting unit (8) between described CPU (central processing unit) (1) and the described PI regulon (4), the input end of D/A converting unit (8) links to each other with described CPU (central processing unit) (1), and the output terminal of D/A converting unit (8) links to each other with the normal voltage input end of described PI regulon (4).

3. portable intelligent DC electronic load device according to claim 1, it is characterized in that being connected with A/D converting unit (9) between the output terminal of described CPU (central processing unit) (1) and described electric current and voltage sample circuit (7), the input end of A/D converting unit (9) links to each other with the output terminal of described electric current and voltage sample circuit (7), and the output terminal of A/D converting unit (9) links to each other with described CPU (central processing unit) (1).

4. according to claim 1 or 2 or 3 described portable intelligent DC electronic load devices, it is characterized in that comprising communication unit (10), described CPU (central processing unit) (1) links to each other with communication unit (10), and communication unit (10) links to each other with host computer (21).

5. portable intelligent DC electronic load device according to claim 4, it is characterized in that described communication unit (10) changes usb interface unit for serial ports, serial ports links to each other with described CPU (central processing unit) (1), and USB interface links to each other with described host computer (21).

6. according to claim 1 or 2 or 3 described portable intelligent DC electronic load devices, it is characterized in that described MOSFET driver element (5) is connected with over-voltage over-current protection circuit (11).

7. according to claim 1 or 2 or 3 described portable intelligent DC electronic load devices, it is characterized in that described display unit (2) and described push-button unit (3) adopt liquid crystal touch screen.

8. according to claim 1 or 2 or 3 described portable intelligent DC electronic load devices, it is characterized in that described CPU (central processing unit) (1) adopts the MSP430F149 single-chip microcomputer.

9. according to claim 1 or 2 or 3 described portable intelligent DC electronic load devices, it is characterized in that described power supply unit (6) powered by charged lithium cells.

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