Precise constant current source output device with multiple overcurrent protection

Abstract

The utility model relates to a kind of precision constant-current source output device with multiple overcurrent protection, belong to detection circuit field. Including: band-gap voltage reference source module, voltage conversion module, voltage conversion current constant-current module, precision current limiter module, current detection module, constant-current source automatic switching switch module;The band-gap voltage reference source module connects voltage conversion module, the voltage conversion module connects voltage conversion current constant-current module, the voltage conversion current constant-current module connects precision current limiter module, the precision current limiter module connects current detection module, the current detection module constant-current source automatic switching switch module, the constant-current source automatic switching switch module connects measured equipment, the utility model realizes high stable constant-current source output by multiple stage operational amplifier and triode, and multiple protection of constant-current source is realized by current detection module, and the faulty constant-current source output of quick shutdown can be realized.

Description

Technical Field

[0001] This utility model belongs to the field of detection circuits, specifically relating to a precision constant current source output device with multiple overcurrent protections. Background Technology

[0002] Current constant current source circuit models include three modes: voltage-controlled current source, feedback constant current source, and field-effect transistor constant current source. A standalone constant current source can only achieve constant current output function, but cannot monitor the current magnitude in real time and cut off the constant current output in time when a fault occurs.

[0003] To achieve flexible and safe testing in equipment inspection processes and meet the needs of scientific research product testing and faulty product troubleshooting, a precision constant current source output device with multiple overcurrent protections is proposed. This device can flexibly switch the number of series connections during transient interruption testing of complex cable groups. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] The technical problem to be solved by this utility model is how to provide a precision constant current source output device with multiple overcurrent protection, so as to solve the problem that a single constant current source can only realize the constant current output function, cannot monitor the current magnitude in real time, and can cut off the constant current output in time when a fault occurs.

[0006] (II) Technical Solution

[0007] To solve the above-mentioned technical problems, this utility model proposes a precision constant current source output device with multiple overcurrent protection, including: a bandgap voltage reference source module, a voltage conversion module, a voltage-to-current constant current module, a precision current limiter module, a current detection module, and a constant current source automatic switching switch module.

[0008] The bandgap voltage reference source module is connected to the voltage conversion module, the voltage conversion module is connected to the voltage-to-current constant current module, the voltage-to-current constant current module is connected to the precision current limiter module, the precision current limiter module is connected to the current detection module, the current detection module is connected to the constant current source automatic switching switch module, and the constant current source automatic switching switch module is connected to the equipment under test.

[0009] A resistance wire is connected between the constant current source automatic switching module and the equipment under test.

[0010] The voltage conversion module includes: operational amplifier AMP1, transistor Q1, resistor R1, and resistor R2;

[0011] The transistor Q1 is connected in series with resistors R1 and R2. An operational amplifier AMP1 is connected between resistors R1 and R2 to convert the reference 5V voltage output by the bandgap voltage reference source module into a preset voltage.

[0012] The voltage-to-current constant current module includes: operational amplifier AMP2, resistor RL, resistor RS, and transistor Q2;

[0013] The transistor Q2 is connected in series with resistors RS and RL. The positive terminal of the operational amplifier AMP2 is connected to a series circuit of resistors R1 and R2, and the negative terminal of the operational amplifier AMP2 is connected to a series circuit of resistors RS and RL. The positive input voltage of the operational amplifier AMP2 is converted into a constant current source current through the transistor Q2 and resistor RS.

[0014] (III) Beneficial Effects

[0015] This invention proposes a precision constant current source output device with multiple overcurrent protections. It achieves a highly stable constant current source output through multi-stage operational amplifiers and transistors, and provides multiple protections for the constant current source through a current detection module. Furthermore, it can quickly shut down the faulty constant current source output. Attached Figure Description

[0016] Figure 1 This is a functional block diagram of the low-noise precision bandgap voltage reference of this utility model;

[0017] Figure 2 This is a functional block diagram of the voltage conversion module and constant current module of this utility model;

[0018] Figure 3 This is a circuit block diagram of the precision current limiter module of this utility model;

[0019] Figure 4 This is a functional block diagram of the current detection module of this utility model;

[0020] Figure 5 This is a general functional block diagram of the present utility model. Detailed Implementation

[0021] To make the objectives, contents, and advantages of this utility model clearer, the specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples.

[0022] This embodiment provides a precision constant current source output device with multiple overcurrent protections, including: a bandgap voltage reference source module, a voltage conversion module, a voltage-to-current constant current module, a precision current limiter module, a current detection module, and a constant current source automatic switching switch module;

[0023] The bandgap voltage reference source module is connected to the voltage conversion module, the voltage conversion module is connected to the voltage-to-current constant current module, the voltage-to-current constant current module is connected to the precision current limiter module, the precision current limiter module is connected to the current detection module, the current detection module is connected to the constant current source automatic switching switch module, and the constant current source automatic switching switch module is connected to the equipment under test.

[0024] A resistance wire is connected between the constant current source automatic switching module and the equipment under test.

[0025] The voltage conversion module includes: operational amplifier AMP1, transistor Q1, resistor R1, and resistor R2;

[0026] The transistor Q1 is connected in series with resistors R1 and R2. An operational amplifier AMP1 is connected between resistors R1 and R2 to convert the reference 5V voltage output by the bandgap voltage reference source module into a preset voltage.

[0027] The voltage-to-current constant current module includes: operational amplifier AMP2, resistor RL, resistor RS, and transistor Q2;

[0028] The transistor Q2 is connected in series with resistors RS and RL. The positive terminal of the operational amplifier AMP2 is connected to a series circuit of resistors R1 and R2, and the negative terminal of the operational amplifier AMP2 is connected to a series circuit of resistors RS and RL. The positive input voltage of the operational amplifier AMP2 is converted into a constant current source current through the transistor Q2 and resistor RS.

[0029] The constant current source output function is realized through a bandgap voltage reference source module, a voltage conversion module, and a voltage-to-current constant current module; the constant current source has multiple protection functions through a precision current limiter module, a current detection module, and a constant current source automatic switching switch module.

[0030] The functional block diagram of the bandgap voltage source is as follows: Figure 1 As shown, it can provide a fixed output temperature drift of 3ppm and a high-precision 5V reference voltage of 0.05%.

[0031] Voltage conversion module such as Figure 2 As shown, the reference 5V voltage is converted to a predetermined voltage through the operational amplifier AMP1, transistor Q1, resistors R1 and R2. Changing the resistance value of R2 can change the collector voltage of Q1.

[0032] Voltage-to-current constant current module, such as Figure 2 As shown, the positive input voltage of AMP2 is converted into a precision current through AMP2, transistor Q2 and resistor RS. Changing the resistance value of RS can change the collector and emitter current of Q2.

[0033] Precision current limiter module such as Figure 3 As shown, the constant current source generates a voltage through resistor Rcl. After being superimposed with the reference voltage of TL431, it controls the current amplification factor of the transistor. When the current is greater than Vref / Rcl, the transistor automatically turns off to prevent overcurrent.

[0034] Current detection module such as Figure 4As shown on the left, the constant current source induces a small voltage through the 5Ω Rsense resistor. This voltage then passes through the instrumentation amplifier in the box, outputting an amplified voltage Vout of approximately 5V. This amplified voltage is connected to... Figure 4 The comparator chip on the right can control the overcurrent threshold of the constant current source by changing the resistance values ​​of R1 and R2. When the constant current source exceeds the threshold, the comparator outputs a control signal to the constant current source switching module to automatically shut down the constant current source output, thereby protecting the weapon equipment circuit.

[0035] The constant current source automatic switching module can turn the constant current source output on and off within 30µs. This extremely fast response time ensures the safety of weaponry and equipment.

[0036] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A precision constant current source output device with multiple overcurrent protections, characterized in that, include: Bandgap voltage reference source module, voltage conversion module, voltage-to-current constant current module, precision current limiter module, current detection module, constant current source automatic switching switch module; The bandgap voltage reference source module is connected to the voltage conversion module, the voltage conversion module is connected to the voltage-to-current constant current module, the voltage-to-current constant current module is connected to the precision current limiter module, the precision current limiter module is connected to the current detection module, the current detection module is connected to the constant current source automatic switching switch module, and the constant current source automatic switching switch module is connected to the equipment under test.

2. The precision constant current source output device with multiple overcurrent protection as described in claim 1, characterized in that, A resistance wire is connected between the constant current source automatic switching module and the equipment under test.

3. The precision constant current source output device with multiple overcurrent protection as described in claim 1, characterized in that, The voltage conversion module includes: operational amplifier AMP1, transistor Q1, resistor R1 and resistor R2; The transistor Q1 is connected in series with resistors R1 and R2. An operational amplifier AMP1 is connected between resistors R1 and R2 to convert the reference 5V voltage output by the bandgap voltage reference source module into a preset voltage.

4. The precision constant current source output device with multiple overcurrent protection as described in claim 1, characterized in that, The voltage-to-current constant current module includes: operational amplifier AMP2, resistor RL, resistor RS, and transistor Q2; The transistor Q2 is connected in series with resistors RS and RL. The positive terminal of the operational amplifier AMP2 is connected to a series circuit of resistors R1 and R2, and the negative terminal of the operational amplifier AMP2 is connected to a series circuit of resistors RS and RL. The positive input voltage of the operational amplifier AMP2 is converted into a constant current source current through the transistor Q2 and resistor RS.

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