CN207677424U - A kind of current foldback circuit - Google Patents

A kind of current foldback circuit Download PDF

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Publication number
CN207677424U
CN207677424U CN201721848039.4U CN201721848039U CN207677424U CN 207677424 U CN207677424 U CN 207677424U CN 201721848039 U CN201721848039 U CN 201721848039U CN 207677424 U CN207677424 U CN 207677424U
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CN
China
Prior art keywords
circuit
comparator
voltage reference
voltage
effect tube
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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.)
Expired - Fee Related
Application number
CN201721848039.4U
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Chinese (zh)
Inventor
陈益庆
赖永宽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangan Vocational and Technical College
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Guangan Vocational and Technical College
Priority date (The priority date 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 date listed.)
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Priority to CN201721848039.4U priority Critical patent/CN207677424U/en
Application granted granted Critical
Publication of CN207677424U publication Critical patent/CN207677424U/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

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Abstract

A kind of current foldback circuit provided by the utility model; including sampling resistor, comparator, latching circuit, regulator circuit, latching circuit, field-effect tube driving circuit and output power field-effect tube; regulator circuit is used for the power supply of comparator, latching circuit, and the benchmark as Voltage Reference.Electric current flows through the voltage of sampling resistor generation as collection voltages, and Voltage Reference is inputted as the forward signal of comparator, and comparator compares collection voltages and the size of voltage reference value.When collection voltages are more than voltage reference value, comparator exports high level to latching circuit, and control field-effect tube drive circuit realizes overcurrent protection to close output power field-effect tube after self-locking occurs for latching circuit.The reference threshold that Voltage Reference is set by adjusting outer connecting resistance, to adapt to the overcurrent protection function of different electric currents;Simultaneously by adjusting the overcurrent time for the external capacitor initialization circuit that the overcurrent time is arranged in circuit, circuit is simple, cheap.

Description

A kind of current foldback circuit
Technical field
The utility model is related to electro-detection technology fields, and in particular to a kind of current foldback circuit.
Background technology
In electronic product during designing and developing, the safety and reliability of guarantee system work is that all engineers must The matter of utmost importance that must be considered, that is to say, that system allows for detecting the every operating parameter of itself automatically, to prevent The accidentalia such as stream, overvoltage cause system by irreversible damage.The electronics to work in severe outdoor environment for some There is product overcurrent protection function to be just particularly important.Because outdoor bad environments, various unpredictable factors have Phenomena such as may causing power supply instantaneous short circuit, and then irreversible damage is caused to electronic product.
Traditional current foldback circuit uses charging management chip, is used in the electronic product of some low costs It is the power management chip of low cost, and the power management chip of low cost does not have the function of overcurrent monitoring, therefore build a set of Of low cost, Parameter adjustable current foldback circuit is just particularly important.
Utility model content
For the defects in the prior art, the utility model provides a kind of current foldback circuit, by the way that outer connecting resistance is arranged, To realize overcurrent protection, circuit is simple, of low cost.
A kind of current foldback circuit provided by the utility model, include according to be sequentially connected the sampling resistor connect, comparator and Latching circuit further includes regulator circuit, and regulator circuit is to comparator, latching circuit power supply and the regulator circuit for making For Voltage Reference;Voltage Reference is inputted as the forward signal of comparator, and comparator compares the voltage value and voltage of sampling resistor The size of reference value, when sampling resistor voltage is more than reference voltage, comparator exports high level to latching circuit;Latching circuit It is connected with field-effect tube driving circuit, field-effect driving circuit is connected with output power field-effect tube, and latching circuit occurs certainly Field-effect driving circuit is controlled after lock to close output power field-effect tube;Outer connecting resistance on Voltage Reference adjusts outer connecting resistance To set voltage reference threshold.
Further, regulator circuit generates 3V voltage differences.
Further, regulator circuit is connected with constant-current circuit, and constant-current circuit generates the constant-current source of 3mA.
Further, the both ends parallel connection external capacitor of sampling resistor, when by the way that the external capacitor is arranged to determine overcurrent Between, the overcurrent time inputs as the negative-going signal of comparator.
Further, outer connecting resistance exchangeable number.
Further, the replaceable model of external capacitor.
As shown from the above technical solution, the beneficial effects of the utility model:
The utility model provides a kind of current foldback circuit, include according to be sequentially connected the sampling resistor connect, comparator and from Lock circuit, further includes regulator circuit, and regulator circuit is used for the power supply of comparator, latching circuit, and the base as Voltage Reference It is accurate.Electric current flows through the voltage of sampling resistor generation as collection voltages, and Voltage Reference is inputted as the forward signal of comparator, than Compare collection voltages and the size of voltage reference value compared with device.When collection voltages are more than voltage reference value, the high electricity of comparator output It puts down to latching circuit, latching circuit is connected with field-effect tube driving circuit, field-effect tube driving circuit and output power field-effect Pipe is connected, and control field-effect tube drive circuit was realized with closing output power field-effect tube after self-locking occurs for latching circuit Stream protection.The reference threshold that Voltage Reference is set by adjusting outer connecting resistance, to adapt to the overcurrent protection function of different electric currents;Together When can by adjust the overcurrent time be arranged circuit in external capacitor initialization circuit the overcurrent time, circuit is simple, and price is low It is honest and clean.
Description of the drawings
It, below will be right in order to illustrate more clearly of specific embodiment of the present invention or technical solution in the prior art Specific implementation mode or attached drawing needed to be used in the description of the prior art are briefly described.In all the appended drawings, similar Element or part are generally identified by similar reference numeral.In attached drawing, each element or part might not be according to actual ratios It draws.
Fig. 1 is a kind of connection diagram of current foldback circuit of the utility model.
Specific implementation mode
The embodiment of technical solutions of the utility model is described in detail below in conjunction with attached drawing.Following embodiment is only For clearly illustrating the technical solution of the utility model, therefore it is only used as example, and this practicality cannot be limited with this Novel protection domain.
It should be noted that unless otherwise indicated, technical term or scientific terminology used in this application should be this reality The ordinary meaning understood with novel one of ordinary skill in the art.
Referring to Fig. 1, a kind of current foldback circuit provided in this embodiment, include according to be sequentially connected the sampling resistor connect, The input voltage of comparator and latching circuit, sampling resistor is 5-36V, further includes regulator circuit, and regulator circuit generates 3V voltages Difference, regulator circuit are used to be used as Voltage Reference to comparator, latching circuit power supply and the regulator circuit;Voltage Reference is made It is inputted for the forward signal of comparator, comparator compares the voltage value of sampling resistor and the size of voltage reference value, and electric current passes through Sampling resistor generates voltage, and when sampling resistor voltage is more than reference voltage, comparator exports high level to latching circuit;Self-locking Circuit is connected with field-effect tube driving circuit, and control field-effect driving circuit is closed after self-locking occurs for latching circuit.Voltage Reference Upper outer connecting resistance adjusts outer connecting resistance to set voltage reference threshold, and to adapt to the overcurrent protection of different electric currents, circuit is simple, It is cheap.
Regulator circuit is connected with constant-current circuit, and constant-current circuit generates the constant-current source of 3mA, solves conventional regulator circuit and is inputting Oneself power consumption high problem when voltage is relatively high.
The both ends parallel connection external capacitor of sampling resistor, using capacitor charge and discharge principle, by the way that external capacitor is arranged with determination Overcurrent time, overcurrent time >=1ms, overcurrent time input as the negative-going signal of comparator.
Outer connecting resistance and external capacitor are replaceable, according to the difference of actual demand, replace different model outer connecting resistance and External capacitor, of low cost, Parameter adjustable.
Finally it should be noted that:The above various embodiments is only to illustrate the technical solution of the utility model, rather than limits it System;Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should Understand:It still can be with technical scheme described in the above embodiments is modified, either to which part or whole Technical characteristic carries out equivalent replacement;And these modifications or replacements, this practicality that it does not separate the essence of the corresponding technical solution are new The range of each embodiment technical solution of type, should all cover in the claim of the utility model and the range of specification.

Claims (6)

1. a kind of current foldback circuit, it is characterised in that:Include electric according to the sampling resistor, comparator and self-locking that connect is sequentially connected Road further includes regulator circuit, and the regulator circuit is used for conduct to comparator, latching circuit power supply and the regulator circuit Voltage Reference;The Voltage Reference is inputted as the forward signal of comparator, and the comparator compares the voltage value of sampling resistor With the size of voltage reference value, when sampling resistor voltage is more than reference voltage, comparator exports high level to latching circuit;Institute It states latching circuit and is connected with field-effect tube driving circuit, the field-effect tube driving circuit is connected with output power field-effect tube It connects, control field-effect driving circuit is to close output power field-effect tube after self-locking occurs for the latching circuit;The voltage ginseng It is admitted to outer connecting resistance, adjusts outer connecting resistance to set voltage reference threshold.
2. a kind of current foldback circuit according to claim 1, it is characterised in that:The regulator circuit generates 3V voltages Difference.
3. a kind of current foldback circuit according to claim 2, it is characterised in that:The regulator circuit is connected with Constant Electric Current Road, the constant-current circuit generate the constant-current source of 3mA.
4. a kind of current foldback circuit according to claim 1, it is characterised in that:The both ends of the sampling resistor are in parallel outer Capacitance is connect, by the way that the external capacitor is arranged to determine that overcurrent time, the overcurrent time are defeated as the negative-going signal of comparator Enter.
5. a kind of current foldback circuit according to any one of claims 1-4, it is characterised in that:The outer connecting resistance can Replace model.
6. a kind of current foldback circuit according to claim 4, it is characterised in that:The replaceable model of external capacitor.
CN201721848039.4U 2017-12-26 2017-12-26 A kind of current foldback circuit Expired - Fee Related CN207677424U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201721848039.4U CN207677424U (en) 2017-12-26 2017-12-26 A kind of current foldback circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201721848039.4U CN207677424U (en) 2017-12-26 2017-12-26 A kind of current foldback circuit

Publications (1)

Publication Number Publication Date
CN207677424U true CN207677424U (en) 2018-07-31

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN201721848039.4U Expired - Fee Related CN207677424U (en) 2017-12-26 2017-12-26 A kind of current foldback circuit

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CN (1) CN207677424U (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110890738A (en) * 2018-09-07 2020-03-17 深圳市芯卓微科技有限公司 Charging interface overcurrent turn-off protection circuit
CN112993933A (en) * 2021-04-22 2021-06-18 宜宾听点科技有限公司 Self-recovery protection circuit and device
CN114465198A (en) * 2022-03-10 2022-05-10 陕西瑞禾景明科技有限公司 Abnormal current control circuit and control method of geophone

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110890738A (en) * 2018-09-07 2020-03-17 深圳市芯卓微科技有限公司 Charging interface overcurrent turn-off protection circuit
CN112993933A (en) * 2021-04-22 2021-06-18 宜宾听点科技有限公司 Self-recovery protection circuit and device
CN112993933B (en) * 2021-04-22 2021-08-17 宜宾听点科技有限公司 Self-recovery protection circuit and device
CN114465198A (en) * 2022-03-10 2022-05-10 陕西瑞禾景明科技有限公司 Abnormal current control circuit and control method of geophone
CN114465198B (en) * 2022-03-10 2023-01-24 陕西瑞禾景明科技有限公司 Abnormal current control circuit and control method of geophone

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GR01 Patent grant
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20180731

Termination date: 20201226

CF01 Termination of patent right due to non-payment of annual fee