CN214670296U - Multi-channel constant-current source direct-current electronic load device based on operational amplifier - Google Patents
Multi-channel constant-current source direct-current electronic load device based on operational amplifier Download PDFInfo
- Publication number
- CN214670296U CN214670296U CN202121368468.8U CN202121368468U CN214670296U CN 214670296 U CN214670296 U CN 214670296U CN 202121368468 U CN202121368468 U CN 202121368468U CN 214670296 U CN214670296 U CN 214670296U
- Authority
- CN
- China
- Prior art keywords
- operational amplifier
- mosfet
- input end
- power supply
- electronic load
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Amplifiers (AREA)
- Continuous-Control Power Sources That Use Transistors (AREA)
Abstract
The utility model discloses a multichannel constant current source direct current electronic load device based on operational amplifier, belonging to the field of electronic load, comprising an operational amplifier, a MOSFET and a reference power supply, wherein the operational amplifier comprises a first-stage operational amplifier and a second-stage operational amplifier; one input end of the MOSFET is connected with a power supply to be tested, the other input end of the MOSFET is connected with the output end of the secondary operational amplifier, and the output end of the MOSFET is connected with the input end of the primary operational amplifier; the output end of the primary operational amplifier is connected with the negative electrode of the input end of the secondary operational amplifier, and the positive electrode of the input end of the secondary operational amplifier is connected with the reference power supply. The utility model discloses can the absorbed current size freely adjust, not influenced by equipment under test output voltage to electron load current absorbing capacity has the negative feedback characteristic, can let load current remain stable for a long time.
Description
Technical Field
The utility model belongs to the field of electronic load, concretely relates to multichannel constant current source direct current electronic load device based on operational amplifier.
Background
An electronic load is a device that consumes electrical energy by means of the dissipated power of a power tube by controlling the amount of conduction (magnitude of the quantum duty cycle) of an internal power (MOSFET) or transistor. The load current detection circuit can accurately detect load voltage, accurately adjust load current and simultaneously realize the short circuit of a simulation load, wherein the simulation load is inductive resistance and capacitance, and the rise time of the capacitive load current.
At present, a cement resistor is used as a load to consume power, the cement resistor is formed by winding a resistor on an alkali-free heat-resistant porcelain, adding heat-resistant, moisture-resistant and corrosion-resistant materials to protect and fix the resistor, placing the wound resistor in a square porcelain frame, and filling and sealing the square porcelain frame with special non-combustible heat-resistant cement. However, due to the characteristics of the cement resistor material, the temperature coefficient of the cement resistor is high, and the resistance value is increased along with the increase of the resistance temperature. Therefore, when the cement resistor is used as a load of the constant-voltage output power supply, according to ohm's law, the load current is reduced due to the increase of the resistance value of the cement resistor, and the power supply to be measured cannot work in a target state. Meanwhile, when different currents need to be drawn, a cement resistor with a specific resistance value must be searched to obtain a target current, so that the adjustment of the load current is very inconvenient.
In view of this, the present invention is especially provided.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a multichannel constant current source direct current electronic load device based on operational amplifier, its absorbed current size can freely be adjusted, is not influenced by equipment under test output voltage to electronic load current absorption capacity has the negative feedback characteristic, can let load current keep stable for a long time.
In order to achieve the above object, the present invention provides an operational amplifier-based multi-channel constant current source dc electronic load device, which includes an operational amplifier, a MOSFET and a reference power supply, wherein the operational amplifier includes a first-stage operational amplifier and a second-stage operational amplifier; one input end of the MOSFET is connected with a power supply to be tested, the other input end of the MOSFET is connected with the output end of the secondary operational amplifier, and the output end of the MOSFET is connected with the input end of the primary operational amplifier; the output end of the primary operational amplifier is connected with the negative electrode of the input end of the secondary operational amplifier, and the positive electrode of the input end of the secondary operational amplifier is connected with the reference power supply.
Furthermore, the primary operational amplifier and the secondary operational amplifier are both powered by a 5V power supply.
Further, a comparison resistor is connected in parallel between the positive pole and the negative pole of the input end of the primary operational amplifier.
Further, the output end of the primary operational amplifier is connected with the negative input end of the MOSFET through a resistor.
Further, the LED lamp also comprises a fin radiator and a brushless direct current fan, wherein the fin radiator is used for radiating heat for the MOSFET.
Further, the reference power supply uses a precision potentiometer and a high-precision reference voltage source.
Furthermore, the circuit comprises 4 circuits which are respectively composed of an operational amplifier, a MOSFET and a reference power supply and are respectively connected with the power supply to be tested.
The utility model provides a pair of multichannel constant current source direct current electronic load device based on operational amplifier has following beneficial effect: the utility model has the characteristics of low cost, multichannel, high stability, not fragile, convenient to use, can improve power product test efficiency, long-term the use also can keep load current stable, and is easy and simple to handle, shows directly perceived.
Drawings
Fig. 1 is a circuit connection diagram of the multi-channel constant current source dc electronic load device based on the operational amplifier of the present invention.
Detailed Description
In order to make the technical field better understand the solution of the present invention, the present invention will be further described in detail with reference to the following embodiments.
As shown in fig. 1, the multi-channel constant current source dc electronic load device based on the operational amplifier comprises the operational amplifier and a high power MOSFET U1. The MOSFET U1 is further provided with an auxiliary heat dissipation element for dissipating heat of the MOSFET, the auxiliary heat dissipation element comprises a fin radiator and a brushless direct current fan, and the fin radiator and the brushless direct current fan are used for providing necessary heat dissipation for the MOSFET, so that the MOSFET works in a safe working area, and long-term stable work of a circuit is guaranteed.
The operational amplifier can be used as a control device, the high-power MOSFET can be used as a power consumption device, the MOSFET works in the variable resistance area by controlling the grid voltage of the MOSFET, and the power supply power is completely dissipated by the heat of the MOSFET.
A Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is a Field-Effect Transistor (fet) that can be widely used in analog circuits and digital circuits.
The operational amplifier includes a primary operational amplifier U2 and a secondary operational amplifier U3. The operational amplifier is an electronic integrated circuit containing a multi-stage amplifying circuit, the input stage of the operational amplifier is a differential amplifying circuit, and the operational amplifier has high input resistance and zero drift suppression capability; the intermediate stage mainly performs voltage amplification, has high voltage amplification factor and is generally composed of a common emitter amplification circuit; the output pole is connected with the load, and has the characteristics of strong loading capacity and low output resistance.
An input end of the MOSFET U1 is connected with a tested power supply VS1, and is used for drawing a constant current from the tested power supply VS1, the power of the constant current is totally dissipated by the MOSFET, and the magnitude of a load current Id is controlled by controlling the grid voltage of the MOSFET, wherein the load current Id is the current of the output end of the MOSFET U1.
The other input of the MOSFET U1 is connected to the output of the secondary operational amplifier U3, and the output of the MOSFET U1 is connected to the input of the primary operational amplifier U2. The output end of the primary operational amplifier U2 is connected with the negative electrode of the input end of the secondary operational amplifier U3, and the positive electrode of the input end of the secondary operational amplifier U3 is connected with the reference voltage VG 1.
The primary operational amplifier U2 and the secondary operational amplifier U3 are both powered by a 5V power supply.
The utility model discloses a multichannel constant current source direct current electronic load device based on operational amplifier still includes reference power supply, and it provides reference voltage VG 1.
The comparison resistor R1 is connected in parallel between the positive electrode and the negative electrode of the input end of the primary operational amplifier U2, namely, the load current Id is sampled by the comparison resistor R1 and generates comparison voltage through the primary operational amplifier U2, the voltage and the reference voltage VG1 are compared and amplified through the secondary operational amplifier U3 to generate MOSFET gate drive control voltage Vg, and then the load current Id is controlled through the control voltage Vg, so that the purpose of adjusting the load current can be achieved.
The reference power supply uses a precision potentiometer and a high-precision reference voltage source to provide high-precision reference voltage regulation.
In addition, the output end of the primary operational amplifier U2 is connected with the negative input end of the MOSFET U1 through the resistor R9, so that the output voltage of the primary operational amplifier U2 enters the negative input end of the U1 through the resistor R9, the negative feedback control of the control voltage Vg is realized, the purpose of stabilizing the control voltage Vg is achieved, and the control voltage Vg can be accurately adjusted.
The four circuits consisting of the operational amplifier and the high-power MOSFET are connected to a power supply to be tested, namely 4 paths of MOSFET circuits are arranged, so that the multi-channel independent control is realized, and the load current is stably absorbed together.
The utility model discloses a precision adjustable resistance (use promptly reference voltage VG1 as equivalent replacement) and high accuracy voltage benchmark, MOSFET's grid voltage is adjusted to the high accuracy to the load current size of MOSFET is flowed through in the high accuracy control. The radiator and the fan provide necessary heat dissipation, and long-term stable work of the circuit is guaranteed.
In order to protect the MOSFET to work in a safe area, an overcurrent protection circuit and an upper limit of load current can be set, and the MOSFET load current is limited in a safe area. The overcurrent protection circuit is not shown in the figure, and is an electronic fuse circuit or a fuse circuit having a self-recovery function, and the upper limit of the load current is set by the overcurrent protection circuit.
The device of the utility model also comprises a digital display voltage and current meter, the meter head of the current meter is connected with a comparison resistor R1 of the load circuit, and the current of the power supply to be measured can be displayed; the voltmeter gauge outfit is connected into the power supply to be tested, and can display the voltage of the power supply to be tested. The output voltage of the power supply to be tested and the current load current are displayed by using the nixie tube, so that the aim of conveniently adjusting the load current is fulfilled.
Furthermore, the utility model discloses can be connected to respectively by survey power through setting up multiunit MOSFET, and then can realize multichannel absorbed current, reach the purpose that facilitates the use and test. And the power dissipation of 80W can be realized by matching with a radiator and a radiating fan.
The inventive concept is explained in detail herein using specific examples, and the above description of the embodiments is only used to help understand the core idea of the present invention. It should be understood that any obvious modifications, equivalents and other improvements made by those skilled in the art without departing from the spirit of the present invention are intended to be included within the scope of the present invention.
Claims (7)
1. A multi-channel constant current source direct current electronic load device based on an operational amplifier is characterized by comprising an operational amplifier, an MOSFET and a reference power supply, wherein the operational amplifier comprises a primary operational amplifier and a secondary operational amplifier; one input end of the MOSFET is connected with a power supply to be tested, the other input end of the MOSFET is connected with the output end of the secondary operational amplifier, and the output end of the MOSFET is connected with the input end of the primary operational amplifier; the output end of the primary operational amplifier is connected with the negative electrode of the input end of the secondary operational amplifier, and the positive electrode of the input end of the secondary operational amplifier is connected with the reference power supply.
2. The op-amp based multi-channel constant current source dc electronic load device of claim 1, wherein the primary and secondary op-amps are powered by a 5V power supply.
3. The operational amplifier based multi-channel constant current source dc electronic load device according to claim 1, wherein a comparison resistor is connected in parallel between the positive electrode and the negative electrode of the input terminal of the primary operational amplifier.
4. The operational amplifier based multi-channel constant current source dc electronic load device according to claim 1, wherein the output terminal of the primary operational amplifier is connected to the negative input terminal of the MOSFET through a resistor.
5. The op-amp based multi-channel constant current source dc electronic load device of claim 1 further comprising a fin heat sink and a brushless dc fan for dissipating heat from the MOSFETs.
6. The op-amp based multi-channel constant current source dc electronic load device of claim 1, wherein the reference power source uses a precision potentiometer and a high precision reference voltage source.
7. The device of claim 1, comprising 4 circuits of the operational amplifier, the MOSFET and the reference power source, which are respectively connected to the power source to be tested.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121368468.8U CN214670296U (en) | 2021-06-18 | 2021-06-18 | Multi-channel constant-current source direct-current electronic load device based on operational amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121368468.8U CN214670296U (en) | 2021-06-18 | 2021-06-18 | Multi-channel constant-current source direct-current electronic load device based on operational amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214670296U true CN214670296U (en) | 2021-11-09 |
Family
ID=78496699
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121368468.8U Active CN214670296U (en) | 2021-06-18 | 2021-06-18 | Multi-channel constant-current source direct-current electronic load device based on operational amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214670296U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114610103A (en) * | 2022-03-08 | 2022-06-10 | 常州浩仪科技有限公司 | Electronic load constant voltage mode control circuit and working method thereof |
-
2021
- 2021-06-18 CN CN202121368468.8U patent/CN214670296U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114610103A (en) * | 2022-03-08 | 2022-06-10 | 常州浩仪科技有限公司 | Electronic load constant voltage mode control circuit and working method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205646432U (en) | Semiconductor laser drive circuit | |
| CN214670296U (en) | Multi-channel constant-current source direct-current electronic load device based on operational amplifier | |
| CN103630820A (en) | High-power LED heat resistance measuring device and method of measuring high-power LED heat resistance thereby | |
| CN104768303B (en) | LED drive control circuits | |
| CN211123821U (en) | Linear voltage stabilizing circuit applied to ammeter and terminal | |
| CN206433225U (en) | A kind of piecewise linearity constant current LED drive circuit | |
| CN106656067B (en) | High-voltage high-power amplifying circuit designed by common operational amplifier | |
| CN210838444U (en) | Laser driving power supply for dynamically tracking and adjusting current and voltage | |
| CN203275469U (en) | Switch-type electronic load | |
| CN203690702U (en) | Laser tube driving circuit for infrared sensor | |
| CN106301068B (en) | A kind of digital driving power | |
| CN201159760Y (en) | Adjustable DC electronic load device | |
| CN102625528A (en) | Constant-current control circuit and electronic equipment | |
| CN203204485U (en) | Band-gap reference circuit | |
| CN104102268B (en) | A kind of constant-current type high-power electronic load control circuit | |
| CN202331248U (en) | Power source stabilizing device with one power source and capable of regulating voltage from zero volt | |
| CN206149157U (en) | Commercial power step -down voltage stabilizing circuit | |
| CN201210261Y (en) | Highly precise low voltage difference linear voltage stabilizing circuit | |
| CN210442473U (en) | Transient thermal resistance test circuit | |
| CN206674255U (en) | A kind of constant-current source circuit based on deep ultraviolet UVLED bactericidal lamps | |
| CN209375459U (en) | A kind of high voltage low ripple output circuit | |
| CN208079468U (en) | The controlled constant-current source circuit of Linear Control | |
| CN206400386U (en) | Exchange closed loop controlled buck circuit based on transistor | |
| CN206542330U (en) | A kind of auto-excitation type Buck converters based on controllable accurate source of stable pressure | |
| CN105404348B (en) | A kind of electric current linearity control circuit for constant-current source |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |