CN220401609U - Constant current source device - Google Patents
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- CN220401609U CN220401609U CN202322003554.4U CN202322003554U CN220401609U CN 220401609 U CN220401609 U CN 220401609U CN 202322003554 U CN202322003554 U CN 202322003554U CN 220401609 U CN220401609 U CN 220401609U
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Abstract
The utility model discloses a constant current source device, which comprises a power supply reverse connection prevention circuit, a voltage reference circuit and a constant current generation circuit; the input end of the power supply anti-reverse connection circuit is electrically connected with an external power supply, the output end of the power supply anti-reverse connection circuit is electrically connected with the input end of the constant current generation circuit through the voltage reference circuit, the output end of the power supply anti-reverse connection circuit is directly electrically connected with the input end of the constant current generation circuit, and the output end of the constant current generation circuit is electrically connected with an external load. The constant current is generated based on the high-precision reference voltage provided by the voltage reference circuit, the current is not changed when the external load fluctuates, and the high-precision constant current output device can still maintain high output precision in the milliamp-level constant current source, and really realizes the low-current constant current output.
Description
Technical Field
The utility model relates to the field of electronic devices, in particular to a constant current source device.
Background
The constant current source is a high-precision constant current power supply suitable for wide load, has the advantages of high response speed, high constant current precision, long-term stable operation and the like, and is mainly applied to occasions needing to set rated current, action current, short-circuit protection current and the like.
The common basic current source circuit comprises a mirror current source circuit, a proportional current source circuit, a micro current source circuit and the like, and most of the application of the power source circuit is applied to a transistor, so that the influence of the base current of the transistor on the output of a constant current source is ignored, the output precision of the constant current source is influenced, and the constant current source with high-precision output cannot be realized. Especially in the circuit of the low-current constant current source, such as the milliamp-level constant current source, the output precision of the constant current source is poor, and the low-current constant current output cannot be really realized.
Disclosure of Invention
In view of the above, the utility model provides a constant current source device to solve the problems that the output precision of the existing constant current source circuit is poor and the current source circuit cannot adapt to the use environment of small current constant current output.
The utility model provides a constant current source device, which comprises a power supply reverse connection prevention circuit, a voltage reference circuit and a constant current generation circuit;
the input end of the power supply anti-reverse connection circuit is electrically connected with an external power supply, the output end of the power supply anti-reverse connection circuit is electrically connected with the input end of the constant current generation circuit through the voltage reference circuit, the output end of the power supply anti-reverse connection circuit is directly electrically connected with the input end of the constant current generation circuit, and the output end of the constant current generation circuit is electrically connected with an external load.
Optionally, the power supply anti-reverse connection circuit comprises a diode D1, a zener diode D2, a capacitor C6 and a connector J1, wherein the connector J1 comprises 3 pins;
the 3 pins of the connector J1 are electrically connected with the external power supply, and the No. 3 pin of the connector J1 is electrically connected with the input end of the voltage reference circuit and the input end of the constant current generation circuit through the diode D1 respectively; the pin 2 of the connector J1 is grounded, the cathode of the zener diode D2 is connected to the common connection end between the diode D1 and the input end of the voltage reference circuit, and the anode of the zener diode D2 is grounded; the first end of the capacitor C6 is connected to the common connection end between the pin 3 of the connector J1 and the diode D1, and the second end of the capacitor C6 is grounded.
Optionally, the connector J1 specifically adopts a KF128-2.54-3P type connector.
Optionally, the zener diode D2 specifically adopts a diode of model LMSZ5245BT 1G.
Optionally, the voltage reference circuit includes a voltage reference chip U1, a resistor R4, a capacitor C2, and a capacitor C3;
the voltage input pin of the voltage reference chip U1 is electrically connected with the output end of the power supply anti-reverse connection circuit, the grounding pin of the voltage reference chip U1 is grounded, and the output pin of the voltage reference chip U1 is electrically connected with the input end of the constant current generation circuit through the resistor R4; the first end of the capacitor C2 is connected to a common connection end between a voltage input pin of the voltage reference chip U1 and the output end of the power supply reverse connection prevention circuit, and the second end of the capacitor C2 is grounded; the first end of the capacitor C3 is connected to a common connection end between the resistor R4 and the input end of the constant current generation circuit, and the second end of the capacitor C3 is grounded.
Optionally, the voltage reference chip U1 specifically adopts a voltage reference chip of AD580UH/883B model.
Optionally, the constant current generating circuit includes an operational amplifier U2, a triode V1, a diode VD1, a resistor R2, a resistor R6, a resistor R7, a resistor R13, a capacitor C1, a capacitor C4, and a capacitor C5;
the voltage input pin of the operational amplifier U2 is electrically connected with the output end of the power supply anti-reverse connection circuit, the first end of the capacitor C5 is connected to the common connection end between the voltage input pin of the operational amplifier U2 and the output end of the power supply anti-reverse connection circuit, and the second end of the capacitor C5 is grounded; the grounding pin of the operational amplifier U2 is grounded; the positive input pin of the operational amplifier U2 is electrically connected with the output end of the voltage reference circuit, the negative input pin of the operational amplifier U2 is electrically connected with the output pin of the operational amplifier U2 through the capacitor C1, and the negative input pin of the operational amplifier U2 is also electrically connected with the negative electrode of an external load through the resistor R7 and the capacitor C4 in sequence; the first end of the resistor R6 is connected to the common connection end between the inverting input pin of the operational amplifier U2 and the capacitor C1, the second end of the resistor R6 and the first end of the resistor R13 are both connected to the common connection end between the capacitor C4 and the negative electrode of the external load, and the second end of the resistor R13 is grounded;
the output pin of the operational amplifier U2 is electrically connected with the base electrode of the triode V1 through the resistor R2, the collector electrode of the triode V1 is electrically connected with the output end of the power supply anti-reverse connection circuit through the resistor R1, the emitter electrode of the triode V1 is electrically connected with the positive electrode of an external load, the positive electrode of the diode VD1 is connected with a public connection end between the emitter electrode of the triode V1 and the positive electrode of the external load, and the negative electrode of the diode VD1 is connected with a public connection end between the resistor R2 and the base electrode of the triode V1.
Optionally, the operational amplifier U2 specifically adopts an operational amplifier model LM158 AJ.
Optionally, the triode V1 specifically adopts a triode of the model S9014.
The utility model has the beneficial effects that: the input end of the power supply reverse connection preventing circuit is electrically connected with an external power supply and is used for accessing the voltage provided by the external power supply to obtain circuit voltage, and meanwhile, the reverse connection of the power supply is prevented in the process of obtaining the circuit voltage, so that the burnout of other circuits in the whole constant current source device caused by the wrong wiring of the power supply is avoided, and the damage of the whole constant current source device is further caused; the output end of the power supply anti-reverse connection circuit is electrically connected with the input end of the voltage reference circuit and the input end of the constant current generation circuit, and is used for providing required circuit voltage for the operation of the voltage reference circuit and the constant current generation circuit respectively, and is convenient for the voltage reference circuit to generate high-precision reference voltage based on the circuit voltage; the input end of the constant current generation circuit is also electrically connected with the output end of the voltage reference circuit and is used for working under the power supply of circuit voltage, generating constant current based on the reference voltage generated by the voltage reference circuit and supplying the constant current to an external load;
the constant current source device generates constant current based on the high-precision reference voltage provided by the voltage reference circuit, does not change the current when an external load fluctuates, can still keep higher output precision in the milliamp-level constant current source, and truly realizes the constant current output of small current.
Drawings
The features and advantages of the present utility model will be more clearly understood by reference to the accompanying drawings, which are illustrative and should not be construed as limiting the utility model in any way, in which:
fig. 1 shows a structure diagram of a constant current source device in an embodiment of the present utility model;
FIG. 2 is a schematic diagram of a power supply anti-reverse circuit according to an embodiment of the utility model;
fig. 3 shows a design diagram of a voltage reference circuit and a constant current generation circuit in an embodiment of the present utility model.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to fall within the scope of the utility model.
As shown in fig. 1, a constant current source device comprises a power supply reverse connection prevention circuit, a voltage reference circuit and a constant current generation circuit;
the input end of the power supply anti-reverse connection circuit is electrically connected with an external power supply, the output end of the power supply anti-reverse connection circuit is electrically connected with the input end of the constant current generation circuit through the voltage reference circuit, the output end of the power supply anti-reverse connection circuit is directly electrically connected with the input end of the constant current generation circuit, and the output end of the constant current generation circuit is electrically connected with an external load.
The constant current source device of the embodiment generates constant current based on the high-precision reference voltage provided by the voltage reference circuit, does not change the current when an external load fluctuates, can still keep higher output precision in the milliamp-level constant current source, and truly realizes the constant current output of small current.
The functions of the above circuits in this embodiment are as follows:
the input end of the power supply reverse connection preventing circuit is electrically connected with an external power supply and is used for accessing the voltage provided by the external power supply to obtain circuit voltage, and meanwhile, the reverse connection of the power supply is prevented in the process of obtaining the circuit voltage.
The reverse connection prevention circuit for the power supply based on the embodiment can effectively avoid the burnout of other circuits in the whole constant current source device caused by the wrong wiring of the power supply, thereby further damaging the whole constant current source device; the output end of the power supply anti-reverse connection circuit is electrically connected with the input end of the voltage reference circuit and the input end of the constant current generation circuit, and is used for providing required circuit voltage for the operation of the voltage reference circuit and the constant current generation circuit respectively, and on the other hand, the voltage reference circuit is convenient for generating high-precision reference voltage based on the circuit voltage.
The voltage reference circuit is used for generating a high-precision reference voltage based on the accessed circuit voltage.
Based on the voltage reference circuit of the embodiment, the follow-up constant current generation circuit is convenient to generate constant current, the current is not changed when external load fluctuates, and the constant current output precision can be effectively ensured in the milliamp-level constant current source.
The input end of the constant current generation circuit is electrically connected with the output end of the voltage reference circuit and is used for working under the power supply of circuit voltage, generating constant current based on the reference voltage generated by the voltage reference circuit and supplying the constant current to an external load.
Based on the constant current generation circuit of the embodiment, high-precision constant current is provided for an external load, so that stable work of the load is ensured, and the reliability of the load is improved.
The utility model improves the hardware circuit of the constant current source device and the electric connection relation between the hardware circuits, and does not relate to the improvement of the computer program.
Preferably, as shown in fig. 2, the power supply anti-reverse connection circuit comprises a diode D1, a zener diode D2, a capacitor C6 and a connector J1, wherein the connector J1 comprises 3 pins;
the 3 pins of the connector J1 are electrically connected with the external power supply, and the No. 3 pin of the connector J1 is electrically connected with the input end of the voltage reference circuit and the input end of the constant current generation circuit through the diode D1 respectively; the pin 2 of the connector J1 is grounded, the cathode of the zener diode D2 is connected to the common connection end between the diode D1 and the input end of the voltage reference circuit, and the anode of the zener diode D2 is grounded; the first end of the capacitor C6 is connected to the common connection end between the pin 3 of the connector J1 and the diode D1, and the second end of the capacitor C6 is grounded.
The power supply reverse connection preventing circuit with the structure is connected with an external power supply through the connector J1, outputs +15V voltage under the condition that the power supply is correctly connected, and respectively supplies the voltage reference circuit and the constant current generating circuit so as to ensure that the voltage reference circuit and the constant current generating circuit can work normally; and under the condition of power supply wiring errors, the electric connection relation between the external power supply and the voltage reference circuit, the constant current source generating circuit and the external load of the later stage can be disconnected, so that the product damage caused by the power supply wiring errors is avoided.
Preferably, the connector J1 is specifically a KF128-2.54-3P type connector.
Preferably, the zener diode D2 is a diode of model LMSZ5245BT 1G.
Specifically, as shown in fig. 2, in this embodiment, the diode D1 is a 1N4148WL type diode, and the capacitor C6 is a 1040/0805/50V type capacitor.
Of course, the connector J1, the zener diode D2, the diode D1 and the capacitor C6 may be any electronic component with other suitable types or specifications according to practical situations.
Preferably, as shown in fig. 3, the voltage reference circuit includes a voltage reference chip U1, a resistor R4, a capacitor C2, and a capacitor C3;
the voltage input pin of the voltage reference chip U1 is electrically connected with the output end of the power supply anti-reverse connection circuit, the grounding pin of the voltage reference chip U1 is grounded, and the output pin of the voltage reference chip U1 is electrically connected with the input end of the constant current generation circuit through the resistor R4; the first end of the capacitor C2 is connected to a common connection end between a voltage input pin of the voltage reference chip U1 and the output end of the power supply reverse connection prevention circuit, and the second end of the capacitor C2 is grounded; the first end of the capacitor C3 is connected to a common connection end between the resistor R4 and the input end of the constant current generation circuit, and the second end of the capacitor C3 is grounded.
By combining the voltage reference circuit with the structure and the power supply reverse connection preventing circuit shown in fig. 2, the high-precision reference voltage 2.5V can be generated according to the +15V voltage output by the power supply reverse connection preventing circuit and transmitted to the constant current generating circuit of the subsequent stage, so that high-precision constant current output is realized.
Preferably, the voltage reference chip U1 specifically adopts a voltage reference chip of AD580UH/883B model.
The voltage reference chip is a three-pin device, has low cost, excellent temperature stability and long-term stability, can provide stable reference voltage, and further ensures that the subsequent constant current generation circuit can generate constant current according to the stable reference circuit.
The specific specifications of the resistor R4 and the capacitors C2 and C3 in this embodiment are shown in fig. 3, and are not described here.
Preferably, as shown in fig. 3, the constant current generating circuit includes an operational amplifier U2, a triode V1, a diode VD1, a resistor R2, a resistor R6, a resistor R7, a resistor R13, a capacitor C1, a capacitor C4, and a capacitor C5;
the voltage input pin of the operational amplifier U2 is electrically connected with the output end of the power supply anti-reverse connection circuit, the first end of the capacitor C5 is connected to the common connection end between the voltage input pin of the operational amplifier U2 and the output end of the power supply anti-reverse connection circuit, and the second end of the capacitor C5 is grounded; the grounding pin of the operational amplifier U2 is grounded; the positive input pin of the operational amplifier U2 is electrically connected with the output end of the voltage reference circuit, the negative input pin of the operational amplifier U2 is electrically connected with the output pin of the operational amplifier U2 through the capacitor C1, and the negative input pin of the operational amplifier U2 is also electrically connected with the negative electrode of an external load through the resistor R7 and the capacitor C4 in sequence; the first end of the resistor R6 is connected to the common connection end between the inverting input pin of the operational amplifier U2 and the capacitor C1, the second end of the resistor R6 and the first end of the resistor R13 are both connected to the common connection end between the capacitor C4 and the negative electrode of the external load, and the second end of the resistor R13 is grounded;
the output pin of the operational amplifier U2 is electrically connected with the base electrode of the triode V1 through the resistor R2, the collector electrode of the triode V1 is electrically connected with the output end of the power supply anti-reverse connection circuit through the resistor R1, the emitter electrode of the triode V1 is electrically connected with the positive electrode of an external load, the positive electrode of the diode VD1 is connected with a public connection end between the emitter electrode of the triode V1 and the positive electrode of the external load, and the negative electrode of the diode VD1 is connected with a public connection end between the resistor R2 and the base electrode of the triode V1.
In the constant current generation circuit with the structure, in combination with the voltage reference circuit in fig. 3, the 2.5V reference voltage V output by the voltage reference circuit is connected to the normal phase input pin of the operational amplifier U2, the output end of the U2 is fed back to the reverse phase input pin of the operational amplifier U2 through the NPN transistor V1, and the 2.5V acts on the resistor R13 to generate a high-precision constant current source; when the external load connected between PI+ and PI-is changed, the difference between the voltage on the resistor R13 and the voltage on the positive input pin of the operational amplifier U2 is amplified by the operational amplifier U2 to control and adjust the base current of the NPN transistor V1 and change the voltage between the emitter and collector of the transistor V1, so that the constant current source output is stable. In the constant current generation circuit with the structure, the load impedance fluctuation does not change the current, and the influence of the base current of the transistor on the output of the constant current source is reduced, so that the high-precision constant current output is realized.
Preferably, the operational amplifier U2 specifically adopts an operational amplifier of model LM158 AJ.
Preferably, the triode V1 is a triode of the model S9014.
Specifically, as shown in FIG. 3, in the present embodiment, a diode VD1 is selected from the type JANTX1N4148 UR-1. The resistor R13 is a direct-insert resistor with the specification of 2.5K/1125mW/0.1%, and the specifications of other resistors and capacitors are shown in FIG. 3 and are not listed here.
Based on the specification and the voltage reference circuit and the constant current generation circuit with the structure shown in fig. 3, the constant current of 1mA plus or minus 0.005mA can be output between PI+ and PI-, and further high-precision constant current output of 1mA level is realized. Of course, the present embodiment may also change the specification or model of the electronic components in the circuit, such as changing the type of the voltage reference chip U1, and further changing the reference voltage at the non-inverting input pin of the op-amp U2, or changing the resistance of the resistor R13, so as to realize constant current output with other small current levels, which will be understood by those skilled in the art.
Although embodiments of the present utility model have been described in connection with the accompanying drawings, various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the utility model, and such modifications and variations are within the scope of the utility model as defined by the appended claims.
Claims (9)
1. The constant current source device is characterized by comprising a power supply reverse connection prevention circuit, a voltage reference circuit and a constant current generation circuit;
the input end of the power supply anti-reverse connection circuit is electrically connected with an external power supply, the output end of the power supply anti-reverse connection circuit is electrically connected with the input end of the constant current generation circuit through the voltage reference circuit, the output end of the power supply anti-reverse connection circuit is directly electrically connected with the input end of the constant current generation circuit, and the output end of the constant current generation circuit is electrically connected with an external load.
2. The constant current source device according to claim 1, wherein the power supply anti-reverse connection circuit comprises a diode D1, a zener diode D2, a capacitor C6, and a connector J1, the connector J1 comprising 3 pins;
the 3 pins of the connector J1 are electrically connected with the external power supply, and the No. 3 pin of the connector J1 is electrically connected with the input end of the voltage reference circuit and the input end of the constant current generation circuit through the diode D1 respectively; the pin 2 of the connector J1 is grounded, the cathode of the zener diode D2 is connected to the common connection end between the diode D1 and the input end of the voltage reference circuit, and the anode of the zener diode D2 is grounded; the first end of the capacitor C6 is connected to the common connection end between the pin 3 of the connector J1 and the diode D1, and the second end of the capacitor C6 is grounded.
3. The constant current source device according to claim 2, wherein the connector J1 is a KF128-2.54-3P type connector.
4. The constant current source device according to claim 2, wherein the zener diode D2 is a diode of model LMSZ5245BT 1G.
5. The constant current source device according to claim 1, wherein the voltage reference circuit includes a voltage reference chip U1, a resistor R4, a capacitor C2, and a capacitor C3;
the voltage input pin of the voltage reference chip U1 is electrically connected with the output end of the power supply anti-reverse connection circuit, the grounding pin of the voltage reference chip U1 is grounded, and the output pin of the voltage reference chip U1 is electrically connected with the input end of the constant current generation circuit through the resistor R4; the first end of the capacitor C2 is connected to a common connection end between a voltage input pin of the voltage reference chip U1 and the output end of the power supply reverse connection prevention circuit, and the second end of the capacitor C2 is grounded; the first end of the capacitor C3 is connected to a common connection end between the resistor R4 and the input end of the constant current generation circuit, and the second end of the capacitor C3 is grounded.
6. The constant current source device according to claim 5, wherein the voltage reference chip U1 is a voltage reference chip of model AD580 UH/883B.
7. The constant current source device according to claim 1, wherein the constant current generation circuit includes an operational amplifier U2, a transistor V1, a diode VD1, a resistor R2, a resistor R6, a resistor R7, a resistor R13, a capacitor C1, a capacitor C4, and a capacitor C5;
the voltage input pin of the operational amplifier U2 is electrically connected with the output end of the power supply anti-reverse connection circuit, the first end of the capacitor C5 is connected to the common connection end between the voltage input pin of the operational amplifier U2 and the output end of the power supply anti-reverse connection circuit, and the second end of the capacitor C5 is grounded; the grounding pin of the operational amplifier U2 is grounded; the positive input pin of the operational amplifier U2 is electrically connected with the output end of the voltage reference circuit, the negative input pin of the operational amplifier U2 is electrically connected with the output pin of the operational amplifier U2 through the capacitor C1, and the negative input pin of the operational amplifier U2 is also electrically connected with the negative electrode of an external load through the resistor R7 and the capacitor C4 in sequence; the first end of the resistor R6 is connected to the common connection end between the inverting input pin of the operational amplifier U2 and the capacitor C1, the second end of the resistor R6 and the first end of the resistor R13 are both connected to the common connection end between the capacitor C4 and the negative electrode of the external load, and the second end of the resistor R13 is grounded;
the output pin of the operational amplifier U2 is electrically connected with the base electrode of the triode V1 through the resistor R2, the collector electrode of the triode V1 is electrically connected with the output end of the power supply anti-reverse connection circuit through the resistor R1, the emitter electrode of the triode V1 is electrically connected with the positive electrode of an external load, the positive electrode of the diode VD1 is connected with a public connection end between the emitter electrode of the triode V1 and the positive electrode of the external load, and the negative electrode of the diode VD1 is connected with a public connection end between the resistor R2 and the base electrode of the triode V1.
8. The constant current source device according to claim 7, wherein the operational amplifier U2 is an operational amplifier of model LM158 AJ.
9. The constant current source device according to claim 7, wherein the transistor V1 is a transistor of model S9014.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322003554.4U CN220401609U (en) | 2023-07-28 | 2023-07-28 | Constant current source device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322003554.4U CN220401609U (en) | 2023-07-28 | 2023-07-28 | Constant current source device |
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| Publication Number | Publication Date |
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| CN220401609U true CN220401609U (en) | 2024-01-26 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202322003554.4U Active CN220401609U (en) | 2023-07-28 | 2023-07-28 | Constant current source device |
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| CN (1) | CN220401609U (en) |
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- 2023-07-28 CN CN202322003554.4U patent/CN220401609U/en active Active
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