CN201754502U - Overcurrent protection device capable of adjusting overcurrent value by software - Google Patents
Overcurrent protection device capable of adjusting overcurrent value by software Download PDFInfo
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- CN201754502U CN201754502U CN201020277985XU CN201020277985U CN201754502U CN 201754502 U CN201754502 U CN 201754502U CN 201020277985X U CN201020277985X U CN 201020277985XU CN 201020277985 U CN201020277985 U CN 201020277985U CN 201754502 U CN201754502 U CN 201754502U
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- 239000003990 capacitor Substances 0.000 claims description 15
- 238000007493 shaping process Methods 0.000 claims description 9
- 230000003321 amplification Effects 0.000 claims description 6
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 6
- 230000001681 protective effect Effects 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 3
- 230000002093 peripheral effect Effects 0.000 claims description 2
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Abstract
The utility model relates to an overcurrent protection device capable of adjusting the overcurrent value by software. The overcurrent protection device is characterized in that a PWM waveform output end of an MCU chip is connected with a reshaping and magnifying circuit; an output end of the reshaping and magnifying circuit is connected into a reference voltage input end of a comparator; a voltage value of a current signal collected is connected with a sample voltage input end of the comparator; and an output end of the comparator is an overcurrent signal output end. The overcurrent protection device can change a hardware overcurrent protection proportional value by adjusting parameters, so as to ensure the generality and adjustability of a hardware protection circuit.
Description
Technical field:
But the utility model relates to the overcurrent protective device that a kind of software was adjusted flow valuve, is applicable to the hardware current foldback circuit of electric automatic control field internal power electric equipment.
Background technology:
For the power electric equipment, each model all has certain rated current, does not allow to surpass rated current in use, not so can damage equipment, so these equipment have just been done the overcurrent protection module.The purpose of overcurrent protection is in order output current to be limited in the scope, to provide guard signal when output short-circuit or overload, whole system or load being protected.
Existing current foldback circuit has two kinds of hardware protection and software protections, and wherein hardware protection circuit speed is fast, adopts Hall or electric resistance sensor to gather electric current equipment is protected, and protection level can reach several microseconds; The software overcurrent protection, it is easy to adjust to cross flow valuve, but response speed is slower, often in several milliseconds; The hardware overcurrent protection is absolutely necessary in the present application.Yet hardware protection circuit hardware protection value commonly used at present all is certain, if adjust, must change the hardware circuit parameter, that is to say and will change components and parts.For with a kind of equipment; the product that a variety of different capacities, different size model are often arranged; the power model that each product uses is different; the plant capacity that drives is different; therefore the parameter of power protecting circuit otherwise with setting, need adjust the protection value according to different power models.It is very loaded down with trivial details to make that like this hardware is crossed the flow valuve adjustment, if concerning the client, it is bigger it to adjust overcurrent protection value difficulty, has limited the versatility and the applicability of product like this.
Summary of the invention:
But the purpose of this utility model provides the overcurrent protective device that a kind of software was adjusted flow valuve, can change hardware overcurrent protection value easily, does not need to adjust hardware circuit or changes components and parts, makes and adjusts the overcurrent protection value simply, conveniently.
The purpose of this utility model realizes as follows: the MCU chip that existing control circuit adopts all has the function that the PWM waveform takes place; the utility model makes full use of this function of MCU; by MCU but the different PWM ripple of certain frequency duty ratio takes place; through obtaining certain voltage after the conversion; as hardware overcurrent protection value, the duty ratio that only need adjust the PWM ripple like this when adjusting hardware overcurrent protection value gets final product.
The PWM waveform output of MCU chip connects shaping amplification circuit, the output of shaping amplification circuit inserts the reference voltage input of comparator, the magnitude of voltage of the current signal that collects is linked into the sampled voltage input of comparator, and the output of comparator is the over-current signal output.
In the shaping amplification circuit, constitute operational amplifier by operational amplifier integrated package and peripheral Resistor-Capacitor Unit, PWM waveform output inserts the operational amplifier input through RC integrating circuit and RC filter circuit, and the output after the shaping of operational amplifier output terminal process integrating circuit is the PWMREF reference voltage.
Insert power supply by the operational amplifier integrated package and constitute comparator, the magnitude of voltage of the current signal that collects is linked into comparator sampled voltage input after through a biasing circuit and RC integrating circuit.
Send the PWM ripple by the MCU chip, behind single order RC filter circuit and RC integrating circuit, obtain the protection magnitude of voltage of needs again by the operational amplifier adjustment, operational amplifier has also played the protection buffer action, is used to protect the MCU chip.The current value that collects enters hardware comparison circuit after treatment, with the magnitude of voltage that is produced by the PWM ripple relatively, produces over-current signal.
The utility model can make hardware protection circuit more possess versatility, controllability by regulating the form change hardware overcurrent protection ratio value of parameter.
Description of drawings:
Accompanying drawing is a circuit diagram of the present utility model.
Embodiment:
With reference to accompanying drawing, the PWM waveform signal is sent by MCU, is a kind of waveform of EDM Generator of Adjustable Duty Ratio, and different as required overcurrent protection value change function corresponding sign indicating numbers goes to change the duty ratio of PWM.At this TMS28015 chip that adopts TI company, this chip has the PWM waveform generator of 8 tunnel enhancement mode, and the PWM waveform can take place under the situation that does not influence other instruction operations constantly.To wherein one the tunnel being provided with, its period register is set makes it that square wave of 1kHz take place, the duty ratio that comparand register can be changed the PWM waveform is set, in running, hardware comparison value as required is converted into corresponding duty ratio, revises comparand register according to duty ratio and periodic quantity.The PWM waveform that produces at first passes through the RC integrating circuit, and square wave is converted to triangular wave, passes through the single order active filter circuit then, obtains its crest voltage, again through obtaining the PWMREF reference voltage after the integrating circuit shaping.In this circuit, the linear direct ratio of PWMREF reference voltage and pulse duty factor, the high more reference voltage that obtains of PWM waveform duty cycle is big more.
Be connected pull-up resistor R1 between the PWM waveform output of MCU chip and the positive source, produce a reference voltage, and strengthened the fan-out capability of PWM waveform; The PWM waveform output of MCU chip connects an integrating resistor R2, is connected integrating capacitor C2 between the rear end of integrating resistor R2 and the power supply ground, and integrating resistor R2 and integrating capacitor C2 have formed the RC integrating circuit, and the PWM ripple of rectangle is converted to triangular wave; Meet filter resistance R3 between input 3 pin of integrating resistor R2 rear end and operational amplifier integrated package U1A, meet filter capacitor C3 between filter resistance R3 rear end and the power supply ground, operational amplifier integrated package U1A and filter resistance R3, filter capacitor C3 constitute an active first-order filtering circuit, obtain the crest voltage of triangular wave; Output 1 pin of operational amplifier integrated package U1A meets current-limiting resistance R5, is used to protect operational amplifier; Connect adjustment resistance R 4 between another input 2 pin of current-limiting resistance R5 rear end and operational amplifier integrated package U1A and be used for hardware adjustment, but the hardware adjustment reference voltage level; 4 pin of operational amplifier integrated package U1A and 8 pin connect power end respectively and meet filter capacitor C1, C5 between the power supply ground; Integrating resistor R6 after the termination behind the current-limiting resistance R5, meet back integrating capacitor C6 between back integrating resistor R6 rear end and the power supply ground, back integrating resistor R6 and back integrating capacitor C6 have formed an integrating circuit, to the crest voltage integration that obtains, obtain final magnitude of voltage PWMREF.Meet back pull-up resistor R7 between back integrating resistor R6 rear end and the positive source, strengthened the load capacity of reference voltage PWMREF.Meet filter capacitor C4 between the contact place of back pull-up resistor R7 and positive source and the power supply ground.
Insert power supply by operational amplifier integrated package U2A and constitute comparator, the PWMREF signal inserts reference voltage input 3 pin of operational amplifier integrated package U2A, be linked into operational amplifier integrated package U2A input 2 pin behind the RC integrating circuit that the magnitude of voltage I process pull-up resistor R9 of the current signal that collects and the biasing circuit that series resistor R8 constitutes and integrating resistor R10 and integrating capacitor C7 constitute, the magnitude of voltage I of the current signal that termination collects before the series resistor R8, the end of the rear end of series resistor R8 and pull-up resistor R9 forms contact, another termination positive source of pull-up resistor R9, the contact of series resistor R8 and pull-up resistor R9 meets integrating resistor R10, sampled voltage input 2 pin of operational amplifier integrated package U2A are inserted in the rear end of integrating resistor R10, meet integrating capacitor C7 between the rear end of integrating resistor R10 and the power supply ground, meet filter capacitor C8 between the 8 pin economize on electricity positive feeder ear in source of operational amplifier integrated package U2A and the power supply ground, 4 pin of U2A connect the power-feeder ear, connect between output 1 pin of operational amplifier integrated package U2A and the positive source and draw resistance R 11, the output 1 pin serial connection back integrating resistor R12 of U2A, meet back integrating capacitor C9 between the rear end of integrating resistor R12 and the power supply ground, integrating resistor R12 is output signal OC with the contact of back integrating capacitor C9.Operational amplifier integrated package U2A compares current value I V and the reference voltage level PWMREF that obtains as voltage comparator, IV be higher than PWMREF then the U2A output low level quote the OC signal; OC signal low level is effective, uses for other circuit.
R1, R2, R3 get 10k respectively in the accompanying drawing, and C2, C3 get 1uf respectively, and R4 gets 1k, and R6, R7 get 3.3k, and when the PWM waveform duty cycle was 70%, measuring the PWMREF value was 2.83v; When the PWM waveform duty cycle was 50%, measuring the PWMREF value was 2.47v; When the PWM duty ratio was 30%, measuring the PWMREF value was 2.20v; Reference voltage of Chan Shenging and PWM duty ratio have linear effects as can be seen.R8, R9, R10 get 1k respectively; C7 gets 330pf; corresponding rated current when being 1.6v with I; then be respectively 70%, 50%, 30% o'clock in the PWM duty ratio; the overcurrent protection ratio is respectively 1.8 times, 1.5 times, 1.2 times; play the effect of regulating the protection ratio, finally satisfied the requirement of adjusting the hardware protection value.
Claims (3)
1. but a software was adjusted the overcurrent protective device of flow valuve; it is characterized in that: the PWM waveform output of MCU chip connects shaping amplification circuit; the output of shaping amplification circuit inserts the reference voltage input of comparator (U2A); the magnitude of voltage of the current signal that collects is linked into the sampled voltage input of comparator (U2A), and the output of comparator (U2A) is the over-current signal output.
2. but software according to claim 1 was adjusted the overcurrent protective device of flow valuve; it is characterized in that: in the shaping amplification circuit; constitute operational amplifier by operational amplifier integrated package (U1A) and peripheral Resistor-Capacitor Unit; PWM waveform output inserts the operational amplifier input through RC integrating circuit and RC filter circuit, and the output after the shaping of operational amplifier output terminal process integrating circuit is the PWMREF reference voltage.
3. but software according to claim 1 was adjusted the overcurrent protective device of flow valuve; it is characterized in that: insert power supply by operational amplifier integrated package (U2A) and constitute comparator, the magnitude of voltage of the current signal that collects is linked into comparator sampled voltage input after through a biasing circuit and RC integrating circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201020277985XU CN201754502U (en) | 2010-07-30 | 2010-07-30 | Overcurrent protection device capable of adjusting overcurrent value by software |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201020277985XU CN201754502U (en) | 2010-07-30 | 2010-07-30 | Overcurrent protection device capable of adjusting overcurrent value by software |
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| CN201754502U true CN201754502U (en) | 2011-03-02 |
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| CN201020277985XU Expired - Fee Related CN201754502U (en) | 2010-07-30 | 2010-07-30 | Overcurrent protection device capable of adjusting overcurrent value by software |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103050144A (en) * | 2012-12-30 | 2013-04-17 | 深圳市凌启电子有限公司 | Power supply transmission circuit of memory card |
| CN104185338A (en) * | 2013-05-27 | 2014-12-03 | 深圳市海洋王照明工程有限公司 | Protection circuit |
| CN104659916A (en) * | 2015-02-02 | 2015-05-27 | 浙江正泰电器股份有限公司 | Signal integral circuit and intelligent circuit breaker controller |
| CN108831361A (en) * | 2018-06-25 | 2018-11-16 | 南京熊猫电子制造有限公司 | A kind of LED backlight drive circuit |
| CN110061476A (en) * | 2019-05-20 | 2019-07-26 | 江苏凯创电子科技有限公司 | Power supply device with overcurrent protection |
| CN113114172A (en) * | 2021-04-30 | 2021-07-13 | 科世达(上海)机电有限公司 | Circuit and device for controlling duty ratio of PWM signal |
| CN114530821A (en) * | 2021-12-31 | 2022-05-24 | 美的集团(上海)有限公司 | Overcurrent protection method and overcurrent protection circuit |
| CN115313315A (en) * | 2022-08-24 | 2022-11-08 | 四川杰诺创科技有限公司 | Dynamic adjusting circuit for thermal measurement ignition threshold of gyrotron traveling wave tube |
-
2010
- 2010-07-30 CN CN201020277985XU patent/CN201754502U/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103050144A (en) * | 2012-12-30 | 2013-04-17 | 深圳市凌启电子有限公司 | Power supply transmission circuit of memory card |
| CN104185338A (en) * | 2013-05-27 | 2014-12-03 | 深圳市海洋王照明工程有限公司 | Protection circuit |
| CN104185338B (en) * | 2013-05-27 | 2017-06-23 | 深圳市海洋王照明工程有限公司 | A kind of protection circuit |
| CN104659916A (en) * | 2015-02-02 | 2015-05-27 | 浙江正泰电器股份有限公司 | Signal integral circuit and intelligent circuit breaker controller |
| CN108831361A (en) * | 2018-06-25 | 2018-11-16 | 南京熊猫电子制造有限公司 | A kind of LED backlight drive circuit |
| CN110061476A (en) * | 2019-05-20 | 2019-07-26 | 江苏凯创电子科技有限公司 | Power supply device with overcurrent protection |
| CN113114172A (en) * | 2021-04-30 | 2021-07-13 | 科世达(上海)机电有限公司 | Circuit and device for controlling duty ratio of PWM signal |
| CN114530821A (en) * | 2021-12-31 | 2022-05-24 | 美的集团(上海)有限公司 | Overcurrent protection method and overcurrent protection circuit |
| CN114530821B (en) * | 2021-12-31 | 2024-12-17 | 美的集团(上海)有限公司 | Overcurrent protection method and overcurrent protection circuit |
| CN115313315A (en) * | 2022-08-24 | 2022-11-08 | 四川杰诺创科技有限公司 | Dynamic adjusting circuit for thermal measurement ignition threshold of gyrotron traveling wave tube |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110302 Termination date: 20130730 |