CN203135403U - Over-current protection circuit for loader - Google Patents
Over-current protection circuit for loader Download PDFInfo
- Publication number
- CN203135403U CN203135403U CN201220705096.8U CN201220705096U CN203135403U CN 203135403 U CN203135403 U CN 203135403U CN 201220705096 U CN201220705096 U CN 201220705096U CN 203135403 U CN203135403 U CN 203135403U
- Authority
- CN
- China
- Prior art keywords
- current
- resistance
- circuit
- triode
- output
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model discloses an over-current protection circuit for a loader. The over-current protection circuit comprises a sensing resistor, a difference amplifier, a comparator, a current control circuit, a constant voltage source, a decoding deck connection interface and an on-off switch, wherein the difference amplifier linearly converses the current flowing through the sensing resistor from the input end of a power supply into voltage value and amplifies the voltage value, the comparator outputs L or H level by comparing the detected voltage value output by the difference amplifier with threshold voltage value, the current control circuit is on upon reception of H level output by the comparator, and the on-off switch is on when the decoding deck is on. When the current control circuit and the on-off switch are on, the input end of the power supply inputs current to the header through the over-current protection circuit. The over-current protection circuit solves the problem of over-current protection of the input port of the header power supply and ESD static damage, thereby minimizing the possibility of damage of the header and lowering the maintenance cost.
Description
Technical field
The utility model relates to the current protection technology field of circuit, relates in particular to a kind of movement shaven head current foldback circuit.
Background technology
As everyone knows, when decoding deck is read the dish aptitude tests, movement (LOADER) need be installed in anchor clamps with thimble decoding deck be connected with LOADER, read the dish test.After in production test procedure, testing some, movement shaven head (LD) on the movement can deterioration damage, and the dish phenomenon is not read in appearance, this mainly is owing to the large impact electric current is arranged by the movement shaven head when powering on, or static releases unusually and to cause, and the infringement of movement shaven head has also caused the raising of the cost of raw material replacings, manpower maintenance undoubtedly.
The utility model content
Main purpose of the present utility model is to provide a kind of movement shaven head current foldback circuit, and the deterioration that being intended to solve the movement shaven head has the large impact electric current to pass through to cause is damaged problem.
To achieve these goals, the utility model provide comprise sensing resistor, be voltage and to the magnitude of voltage of its differential amplifier that amplifies, monitoring differential amplifier output and export the L level and the comparator of H level, the current control circuit of after receiving comparator output H level, realizing self circuit turn-on, decoding deck and realize the on-off switch of self circuit turn-on in the decoding deck back that powers on power input by the current conversion on the described sensing resistor;
Wherein, described sensing resistor, current control circuit and on-off switch are connected to power input in turn to the circuit of power output end, the sensing voltage positive input terminal of described differential amplifier, sensing voltage negative input end are connected with current input terminal, the current output terminal of sensing resistor respectively, and the output of described differential amplifier is connected with the reverse input end of comparator; The output of described comparator is connected with the control end of current control circuit; Described decoding deck is connected with the control end of described on-off switch.
Preferably, described movement shaven head current foldback circuit also comprises static impedance device element (being the ESD element), and described ESD element is arranged between on-off switch and the power output end.
Preferably, described movement shaven head current foldback circuit also comprises the delay driving circuit of delaying time and connecting for the electric current of back output that decoding deck is powered on, and wherein, described delay driving circuit is arranged between on-off switch and the decoding deck.
Preferably, described movement shaven head current foldback circuit comprises that also wherein, described constant pressure source is connected with the positive input of comparator as the constant pressure source of the benchmark of comparator threshold values reference voltage.
Preferably, described differential amplifier comprises first resistance, second resistance, the 4th resistance, first electric capacity and testing current chip; Wherein, described first resistance is imported an end at the sensing resistor electric current and is connected, and the other end is connected with the sensing voltage positive input terminal of testing current chip; Described second resistance is exported an end at the sensing resistor electric current and is connected, and the other end is connected with the sensing voltage negative input end of testing current chip; The output of described testing current chip is connected with comparator; Described the 4th resistance is connected between testing current chip output and the ground; The positive feeder ear of described testing current chip is connected with first power supply, and after being connected in parallel, described testing current chip power supply end, control end and earth terminal circuit be connected with ground, wherein, described first electric capacity is arranged on the positive feeder ear of testing current chip and the circuit that ground is connected.
Preferably, described comparator comprises operational amplifier, second electric capacity, the 3rd electric capacity, the 3rd resistance and the 5th resistance; Described constant pressure source comprises the 12 resistance, a reference source and the 4th electric capacity; Wherein, the reverse input end of described operational amplifier is connected with differential amplifier, and described the 3rd resistance is connected on the connecting circuit between the reverse input end of differential amplifier and operational amplifier; Described second electric capacity and the 5th resistance are connected in series between the reverse input end and output of operational amplifier; The negative feeder ear of described operational amplifier is connected with ground; The positive feeder ear of described operational amplifier is connected with second source and with ground, and described the 3rd electric capacity is connected on the positive feeder ear and the circuit between the ground of operational amplifier;
In addition,
Described the 12 resistance is arranged on the connecting circuit of input in the same way of the 3rd power supply and operational amplifier; The connecting circuit between the input in the same way of described the 12 resistance and operational amplifier is provided with first and second and three tie points, and wherein, described the 4th capacitance current input is connected with the 3rd tie point, and current output terminal is connected with ground; The anode of described a reference source is connected with first tie point, is connected with second tie point with reference to the utmost point, and negative electrode is connected with ground.
Preferably, described current control circuit comprises the 6th resistance, the 7th resistance, the 8th resistance, first triode and second triode, and described first triode is the positive-negative-positive structure, and described second triode is the NPN structure; Wherein, the emitter of described first triode is connected with sensing resistor, and its collector electrode is connected with on-off switch; On emitter one end of described first triode and the connecting circuit of its base stage the 6th resistance is set; Described the 7th resistance is arranged on the connecting circuit of collector electrode of the base stage of first triode and second triode; Described the 8th resistance is arranged on the connecting circuit of base stage of comparator and second triode; The emitter of described second triode is connected with ground.
Preferably, described on-off switch comprises the 9th resistance, switch element, reverse impulse absorption diode and the relay that is made of the tenth resistance, the 11 resistance and the 3rd triode, and described the 3rd triode is the NPN structure; Wherein, the normally opened contact of described switch element is connected with current control circuit; On the connecting circuit on the normally-closed contact that described the 9th resistor current input is arranged on switch element and ground; Described switch element inside arranges a solenoid, is provided with the metal clips that is subjected to this solenoid controlled between the normally-closed contact of described switch element inside and the normally opened contact, and described metal clips one end is connected with the output of switch element; The output of described switch element is connected with the ESD element; Described solenoid and reverse impulse absorption diode form parallel circuits, and the two ends of described parallel circuits are connected with collector electrode and the 4th power supply of the 3rd triode respectively; The current input terminal of described the tenth resistance is connected with decoding deck, and current output terminal is connected with the base stage of the 3rd triode; The current input terminal of described the 11 resistance is arranged on the base stage connecting circuit of current output terminal and the 3rd triode, and is connected with ground after the emitter parallel connection of described the 11 resistance and the 3rd triode.
Preferably, described delay driving circuit comprises delay chip and the 5th electric capacity; Wherein, the input of described delay chip is connected with decoding deck, and described the 5th electric capacity one end is connected on the input and decoding deck connecting circuit of delay chip, and the other end is connected with ground; The earth terminal of described delay chip is connected with ground, and the output of described delay chip is connected with on-off switch.
Preferably, described ESD element comprises the 13 resistance, the 6th electric capacity, filter inductance, static esd protection diode; Wherein, described filter inductance is arranged on the connecting circuit of on-off switch and power output end; the connecting circuit of described filter inductance and power output end is provided with first, second and the 3rd tie point; wherein; the current input terminal of described the 13 resistance, static esd protection diode and the 6th electric capacity is connected with first, second and the 3rd tie point respectively, and is connected with ground after the current output terminal parallel connection of described 13 resistance, static esd protection diode and the 6th electric capacity.
A kind of movement shaven head current foldback circuit that the utility model proposes; comprise sensing resistor; differential amplifier; comparator; current control circuit; decoding deck and on-off switch; wherein; differential amplifier is used for power input being converted to magnitude of voltage and amplifying by the electric current linearity on the sensing resistor; comparator is used for the magnitude of voltage of monitoring differential amplifier output and exports L level and H level according to the set point decision of inner setting; current control circuit is used for turning circuit after receiving comparator output H level; on-off switch is arranged between current control circuit and the power output end; and on-off switch is connected with decoding deck; on-off switch is in power on back conducting and realize the conducting of circuit control circuit and power output end of decoding deck; after power input and decoding deck all power on; when the electric current of power input input during greater than set point; current foldback circuit work; when less than set point; current foldback circuit lost efficacy; thereby make this movement shaven head current foldback circuit limit at the maximum current to the movement circuit input, prevent overcurrent.
Description of drawings
Fig. 1 is the schematic block circuit diagram of a kind of movement shaven head of the utility model current foldback circuit one embodiment.
Fig. 2 is the electrical block diagram of a kind of movement shaven head of the utility model current foldback circuit one embodiment.
The realization of the utility model purpose, functional characteristics and advantage will be in conjunction with the embodiments, are described further with reference to accompanying drawing.
Embodiment
Further specify the technical solution of the utility model below in conjunction with Figure of description and specific embodiment.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
The utility model embodiment solution mainly is: a kind of movement shaven head current foldback circuit is provided; comprise sensing resistor; differential amplifier; comparator; current control circuit; decoding deck and on-off switch; wherein; differential amplifier is used for power input being converted to magnitude of voltage and amplifying by the electric current linearity on the sensing resistor; comparator is used for the magnitude of voltage of monitoring differential amplifier output and exports L level and H level according to the set point decision of inner setting; current control circuit is used for turning circuit after receiving comparator output H level; on-off switch is arranged between current control circuit and the power output end; and on-off switch is connected with decoding deck, and on-off switch is in power on back conducting and realize the conducting of circuit control circuit and power output end of decoding deck.After power input and decoding deck all power on; when the electric current of power input input during greater than set point; current foldback circuit work; when less than set point; current foldback circuit lost efficacy; thereby make this movement shaven head current foldback circuit limit at the maximum current to the movement circuit input, prevent overcurrent.
With reference to Fig. 1, Fig. 1 is the schematic block circuit diagram of a kind of movement shaven head of the utility model current foldback circuit.In the utility model, comprise power input 1, sensing resistor 3, differential amplifier 2, comparator 9, current control circuit 5, constant pressure source 4, decoding deck connecting interface 11, on-off switch 6, ESD element 7, delay driving circuit 10, power output end 8.Wherein, sensing resistor 3, current control circuit 5, on-off switch 6, ESD element 7 are linked in sequence successively at power input 1 to the circuit of power output end 8, in addition, the sensing voltage positive input terminal of differential amplifier 2, sensing voltage negative input end are connected with current output terminal with the current input terminal of sensing resistor 3 respectively, and the current output terminal of differential amplifier 2 is connected with the reverse input end of comparator 9; The output of constant pressure source 4 is connected with the positive input of comparator 9; The output of comparator 9 is connected with the control end of current control circuit 5; Delay driving circuit 10 is connected between on-off switch 6 and the decoding deck 11.
In the utility model, differential amplifier 2 is used for power input 1 being converted to magnitude of voltage and amplifying by the electric current linearity on the sensing resistor 3.Comparator 9 is used for the magnitude of voltage of monitoring differential amplifier 2 outputs, comparator 9 inner settings one comparing voltage value, this comparing voltage value can be regulated according to actual needs, when the magnitude of voltage of comparator 9 reception differential amplifiers 2 outputs is higher than this comparing voltage value, comparator output L level, otherwise, output H level.Current control circuit 5 is used for after receiving comparator 9 output H level, and its internal circuit forms a turning circuit, otherwise, if receive be the L level after, its internal circuit forms an open circuit.On-off switch 6 is in decoding deck 11 energising back conductings.During this time, comparator 9 output high level, current control circuit 5 conductings, at this moment, decoding deck 11 energisings are after on-off switch 6 conductings, finally make between power input 1 and the power output end 8 current path that forms, and give movement (not shown) output current by power output end 8.
In further implementation process, because operate as normal at once after decoding deck 11 powers on, the level of each control mouth is uncertain, there have height to have to be low, the full conducting phenomenon of closing appears in bare headed LD drives the 3rd triode Q3 of movement OPU, cause on the bare headed LD of surge current through movement OPU, bare headed LD deterioration is damaged, have only and to wait until all chip resets, after the normal operation of software, just can obtain the control of various circuit, in order to address this problem, the utility model arranges a delay driving circuit 10 between decoding deck 11 and on-off switch 6, with behind the decoding deck 11 end electric currents time-delays 240ms again by on-off switch 6 conductings.
In further implementation process, instantaneous variation, surge current and the static that occurs for the electric current that prevents on-off switch 6 outputs is to the influence of movement head, and the utility model arranges ESD element 7 by the circuit between on-off switch 6 and power output end 8.
With reference to Fig. 2, Fig. 2 is the electrical block diagram of a kind of movement shaven head of the utility model current foldback circuit preferred embodiment.In the utility model, comprise power input (among the figure not label), sensing resistor 3, differential amplifier 2, comparator 9, current control circuit 5, constant pressure source 4, decoding deck 11, on-off switch 6, power output end (among the figure not label).Wherein, differential amplifier 2 comprises first resistance R 1, second resistance R 2, the 4th resistance R 4, first capacitor C 1 and testing current chip U2; Constant pressure source 4 comprises the 12 resistance R 12, can regulate a reference source D4 and the 4th capacitor C 4 of accurate voltage; Current control circuit 5 comprises the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R 8, the first triode Q1 and the second triode Q2, and the first triode Q1 is the positive-negative-positive structure, and the second triode Q2 is the NPN structure; On-off switch 6 comprises the 9th resistance R 9, switch element K, reverse impulse absorption diode D6 and the relay that is made of the tenth resistance R 10, the 11 resistance R 11 and the 3rd triode Q3, and the 3rd triode Q3 is the NPN structure; Comparator 9 comprises operational amplifier U9, second capacitor C 2, the 3rd capacitor C 3, the 3rd resistance R 3 and the 5th resistance R 5.
Wherein, first resistance R, 1 one ends in the differential amplifier 2 are connected with the current input terminal of sensing resistor 3, and the other end is connected with the sensing voltage positive input terminal j23 of testing current chip U2; Second resistance R, 2 one ends are connected with the current output terminal of sensing resistor 3, and the other end is connected with the sensing voltage negative input end j26 of testing current chip U2; The output j28 of testing current chip U2 is connected with the R3 of comparator 9; The 4th resistance R 4 is connected between the output j28 and ground of testing current chip U2; The chip power supply end j27 of testing current chip U2 is connected with a 5V power supply VCC, and the feeder ear j27 of testing current chip U2, control end j21 and chip earth terminal j24 form parallel circuits and are connected with ground, wherein, on the first capacitor C 1 positive feeder ear j27 that is arranged on testing current chip U2 and the circuit that ground is connected.Sensing resistor 3 is precision resistance, the current value range that resistance and power use according to reality is selected, when the electric current of power input 1 passes through sensing resistor 3, can produce voltage difference at sensing resistor 3 two ends, testing current chip U2 gets access to sensing resistor 3 two ends electric current differences by sensing voltage positive input terminal j23 and sensing voltage negative input end j26, and the linear voltage difference that is converted to is exported from output j28.In actual mechanical process, can be by adjusting sensing resistor 3, the value of first resistance R 1 and second resistance R 2, obtain different ranges, wherein, the relational expression of output voltage and electric current is: output voltage=(accurate sensing resistor x exports the actual current of regulating resistor x institute sensing)/gain resistor.
The 12 resistance R 12 in the constant pressure source 4 is arranged on the connecting circuit of the J93 of input in the same way of the 3rd 5V power supply VCC and operational amplifier U9; Connecting circuit between the J93 of input in the same way of the 12 resistance R 12 and operational amplifier U9 is provided with first and second and three tie points, and wherein, the current input terminal of the 4th capacitor C 4 is connected with the 3rd tie point, and current output terminal is connected with ground; The anode J42 of a reference source D4 is connected with first tie point, is connected with second tie point with reference to utmost point J41, and negative electrode J43 is connected with ground.
The reverse input end J92 of operational amplifier U9 in the comparator 9 is connected with the 3rd resistance R 3; Second capacitor C 2 in the comparator 9 and the 5th resistance R 5 are connected in series between the reverse input end J92 and output J91 of operational amplifier U9, the negative feeder ear J94 of operational amplifier U9 is connected with ground, positive feeder ear J98 is connected with the 2nd 5V power supply VCC and with ground, and the 3rd capacitor C 3 is connected on the positive feeder ear J98 and the circuit between the ground of operational amplifier U9.Operational amplifier U9 receives the voltage difference from positive feeder ear J28 output of testing current chip U2 after through the 3rd resistance R 3, and via the constant pressure source 4 that input J93 place in the same way connects carry out magnitude of voltage constant after, final operational amplifier U9 judges and is converted to L level and H level after this magnitude of voltage size from the output J91 output of operational amplifier U9.
In the concrete application of the utility model foregoing circuit, when the electric current by sensing resistor 3 during less than set point, the output J28 output voltage of testing current chip U2 is less than 2.5V, and operational amplifier U9 is output as the H level; When the electric current by sensing resistor 3 during greater than set point, the output j28 output voltage of testing current chip U2 is greater than 2.5V, and operational amplifier U9 is output as the L level.
In addition, the emitter of the first triode Q1 in the current control circuit 5 is connected with sensing resistor 3, and its collector electrode is connected with the normally opened contact J65 of the switch element of on-off switch 6; On emitter one end of the first triode Q1 and the connecting circuit of its base stage the 6th resistance R 6 is set; The 7th resistance R 7 is arranged on the connecting circuit of collector electrode of the base stage of the first triode Q1 and the second triode Q2; The 8th resistance R 8 is arranged on the connecting circuit of base stage of the output J91 of operational amplifier U9 in the comparator 9 and the second triode Q2; The emitter of the second triode Q2 is connected with ground.Wherein, the base stage of the second triode Q2 is responsible for receiving operational amplifier U9 output level, conducting when the base stage of the second triode Q2 receives the H level, the level of collector electrode becomes L by H, make Vb＜Ve of the first triode Q1, first triode Q1 conducting this moment, power input electric current are passed through sensing resistor 3, current control circuit 5 backs to on-off switch 6 direction output currents; End when the base stage of the second triode Q2 receives the L level, collector electrode gets level and becomes H by L, makes the Vb=Ve of the first triode Q1, and this moment, the first triode Q1 ended, and electric current can't be exported.
Meanwhile, on the basis of current control circuit 5, another one also is set determines power input 1 to the on-off switch 6 of power output end 8 circuit communications.Wherein, on the connecting circuit on the current input terminal of the 9th resistance R 9 in the on-off switch 6 normally-closed contact J63 that is arranged on switch element K and ground; Switch element K inside arranges a solenoid (among the figure not label), and be provided with the metal clips that is subjected to this solenoid controlled (among the figure not label) between the normally-closed contact J63 of switch element K inside and the normally opened contact J65, this metal clips is fixedlyed connected with the output j64 of switch element; Solenoid and reverse impulse absorption diode D6 form parallel circuits, and the two ends of this parallel circuits are connected with collector electrode and the 4th 5V power supply VCC of the 3rd triode Q3 respectively; The current input terminal of the tenth resistance R 10 is connected with decoding deck 11, and current output terminal is connected with the base stage of the 3rd triode Q3; The current input terminal of the 11 resistance R 11 is arranged on the base stage connecting circuit of current output terminal and the 3rd triode Q3, and is connected with ground after the emitter parallel connection of the 11 resistance R 11 and the 3rd triode Q3.Wherein, when decoding deck does not power on, decoding deck end input L level, the 3rd not conducting of triode Q3, at this moment, solenoid does not produce magnetic force, metal clips is connected with normally-closed contact J63, on-off switch 6 circuit pathways disconnections, circuit disconnection between power input 1 and the power output end 8, the electrostatic induced current of residual voltage or generation is released via the 9th resistance R 9 back ground connection of 100 Europe resistances on the power output end 8; After decoding deck powers on, decoding deck end input H level, the 3rd triode Q3 conducting, solenoid produces magnetic force, metal clips moves downward and is connected with normally opened contact J65, electric current realizes finally that by the output J64 output of on-off switch 6 circuit normally connects between power input 1 and the power output end 8.
After decoding deck 11 powers on, simultaneously, the current value of power input 1 output is no more than the lowest high-current value of setting, and current control circuit 5 all can be realized path with on-off switch 6, make the circuit turn-on between power input 1 and the power output end 8, the realization electric current is normally exported.
In further implementation process, because operate as normal at once after decoding deck 11 powers on, the level of each control mouth is uncertain, there have height to have to be low, the full conducting phenomenon of closing appears in the bare headed LD control circuit of movement OPU, cause on the bare headed LD of surge current through movement OPU, bare headed LD deterioration is damaged, have only and to wait until all chip resets, after the normal operation of software, just can make the LD control circuit return to normal operating conditions, in order to address this problem, the utility model arranges a delay driving circuit 10 between decoding deck 11 and on-off switch 6, comprises delay chip U10 and the 5th capacitor C 5; Wherein, the input J103 of delay chip U10 is connected with decoding deck 11, and the 5th capacitor C 5 one ends are connected on the connecting circuit of the input J103 of delay chip U10 and decoding deck 11, and the other end is connected with ground; The earth terminal J101 of delay chip U10 is connected with ground, and time-delay output J102 is connected with the tenth resistance R 10 in the on-off switch.In actual application, delay chip U10 with output H level behind the decoding deck 11 end electric currents time-delay 240ms, and finally makes the 3rd triode Q3 conducting after decoding deck 11 energisings.
In further implementation process, instantaneous variation, surge current and the static that occurs for the electric current that prevents on-off switch 6 output is to the influence of movement head, the utility model arranges ESD element 7 by the circuit between on-off switch 6 and power output end 8, comprises the 13 resistance R 13, the 6th capacitor C 6, filter inductance L1, static esd protection diode D7; Wherein, L1 is connected with power output end 8; the connecting circuit of described L1 and power output end 8 is provided with first, second and the 3rd tie point; wherein; the current input terminal of the 13 resistance R 13, static esd protection diode D7 and the 6th capacitor C 6 is connected with first, second and the 3rd tie point respectively, and is connected with ground after the current output terminal parallel connection of 13 resistance R 13, static esd protection diode D7 and the 6th capacitor C 6.Filter inductance L1 stops instantaneous large-current by inductance, and the static esd protection diode D7 electrostatic pulse voltage of releasing reaches as high as 10KV.
Among the above embodiment; movement shaven head current foldback circuit is mainly used in the current foldback circuit than the precise electronic device current, provides overcurrent protection, short-circuit protection and ESD electrostatic defending such as bare headed LD, laser diode, constant-current source, the power supply of various power supply for CD, DVD and BD video disc player.
In existing movement test process; because corresponding current foldback circuit is not set; this makes movement in use because the passing through of super-high-current; cause the movement shaven head to damage easily; than the deficiencies in the prior art; the utility model is by arranging a current foldback circuit before the input power supply of movement, this makes and the utlity model has following advantage:
(1) movement shaven head current foldback circuit of the present utility model carries out overcurrent protection to the electric current by movement; well protected the movement shaven head; make the movement shaven head more of a specified duration useful life, reduce the raw material use cost, also reduce production line simultaneously and change the cost that damages clamp-replacing and manpower maintenance.
(2) movement of the present utility model shaven head current foldback circuit connects movement circuit again after peripheral circuit is all normal, avoided decoding deck to power on after at once the level of operate as normal, each control mouthful uncertain and after causing the surge current that produces through the movement shaven head shaven head problem damaged appears.
(3) movement of the present utility model shaven head current foldback circuit applied current scope is wide, comprises bare headed LD, laser diode, the constant-current source of CD, DVD and BD video disc player, overcurrent protection, short-circuit protection and the ESD electrostatic defending of various power supply power supply.
(4) movement shaven head current foldback circuit of the present utility model can be regulated maximum current overcurrent protection scope according to the setting of sensing resistor and differential amplifier circuit component parameters, and overcurrent protection threshold values method to set up is simple.
(5) the operation scheme cost of movement shaven head current foldback circuit of the present utility model is low, no environment noise pollution.
The above only is preferred embodiment of the present utility model; be not so limit claim of the present utility model; every equivalent structure or equivalent flow process conversion that utilizes the utility model specification and accompanying drawing content to do; or directly or indirectly be used in other relevant technical fields, all in like manner be included in the scope of patent protection of the present utility model.
Claims (10)
1. movement shaven head current foldback circuit is characterized in that: comprise sensing resistor, be voltage and to the magnitude of voltage of its differential amplifier that amplifies, the output of monitoring differential amplifier and export the L level and the current control circuit of the comparator of H level, conducting after receiving comparator output H level, decoding deck and at the power on on-off switch of back conducting of decoding deck with power input by the current conversion on the described sensing resistor;
Wherein, described sensing resistor, current control circuit and on-off switch are connected to power input in turn to the circuit of power output end, the sensing voltage positive input terminal of described differential amplifier, sensing voltage negative input end are connected with current input terminal, the current output terminal of sensing resistor respectively, and the output of described differential amplifier is connected with the reverse input end of comparator; The output of described comparator is connected with the control end of current control circuit; Described decoding deck is connected with the control end of on-off switch.
2. movement according to claim 1 shaven head current foldback circuit, it is characterized in that: also comprise static impedance device element, described static impedance device element is arranged between on-off switch and the power output end.
3. movement according to claim 2 shaven head current foldback circuit; it is characterized in that: also comprise the delay driving circuit of delaying time and connecting for the electric current of back output that decoding deck is powered on; wherein, described delay driving circuit is arranged between on-off switch and the decoding deck.
4. movement shaven head current foldback circuit according to claim 1 is characterized in that: comprise that also wherein, described constant pressure source is connected with the positive input of comparator as the constant pressure source of the benchmark of comparator threshold values reference voltage.
5. according to each described movement shaven head current foldback circuit of claim 1～4, it is characterized in that: described differential amplifier comprises first resistance, second resistance, the 4th resistance, first electric capacity and testing current chip;
Wherein, described first resistance is imported an end at the sensing resistor electric current and is connected, and the other end is connected with the sensing voltage positive input terminal of testing current chip; Described second resistance is exported an end at the sensing resistor electric current and is connected, and the other end is connected with the sensing voltage negative input end of testing current chip; The output of described testing current chip is connected with comparator; Described the 4th resistance is connected between testing current chip output and the ground;
The positive feeder ear of described testing current chip is connected with first power supply, and after being connected in parallel, described testing current chip power supply end, control end and earth terminal circuit be connected with ground, wherein, described first electric capacity is arranged on the positive feeder ear of testing current chip and the circuit that ground is connected.
6. according to each described movement shaven head current foldback circuit of claim 1～4, it is characterized in that: described comparator comprises operational amplifier, second electric capacity, the 3rd electric capacity, the 3rd resistance and the 5th resistance; Described constant pressure source comprises the 12 resistance, a reference source and the 4th electric capacity; Wherein,
The reverse input end of described operational amplifier is connected with differential amplifier, and described the 3rd resistance is connected on the connecting circuit between the reverse input end of differential amplifier and operational amplifier;
Described second electric capacity and the 5th resistance are connected in series between the reverse input end and output of operational amplifier;
The negative feeder ear of described operational amplifier is connected with ground;
The positive feeder ear of described operational amplifier is connected with second source and with ground, and described the 3rd electric capacity is connected on the positive feeder ear and the circuit between the ground of operational amplifier;
Described the 12 resistance is arranged on the connecting circuit of input in the same way of the 3rd power supply and operational amplifier;
The connecting circuit between the input in the same way of described the 12 resistance and operational amplifier is provided with first and second and three tie points, and wherein, described the 4th capacitance current input is connected with the 3rd tie point, and current output terminal is connected with ground; The anode of described a reference source is connected with first tie point, is connected with second tie point with reference to the utmost point, and negative electrode is connected with ground.
7. according to each described movement shaven head current foldback circuit of claim 1～4, it is characterized in that: described current control circuit comprises the 6th resistance, the 7th resistance, the 8th resistance, first triode and second triode, described first triode is the positive-negative-positive structure, and described second triode is the NPN structure; Wherein,
The emitter of described first triode is connected with sensing resistor, and its collector electrode is connected with on-off switch; On emitter one end of described first triode and the connecting circuit of its base stage the 6th resistance is set;
Described the 7th resistance is arranged on the connecting circuit of collector electrode of the base stage of first triode and second triode;
Described the 8th resistance is arranged on the connecting circuit of base stage of comparator and second triode;
The emitter of described second triode is connected with ground.
8. according to each described movement shaven head current foldback circuit of claim 2～4, it is characterized in that: described on-off switch comprises the 9th resistance, switch element, reverse impulse absorption diode and the relay that is made of the tenth resistance, the 11 resistance and the 3rd triode, and described the 3rd triode is the NPN structure; Wherein,
The normally opened contact of described switch element is connected with current control circuit; On the connecting circuit on the normally-closed contact that described the 9th resistor current input is arranged on switch element and ground; Described switch element inside arranges a solenoid, is provided with the metal clips that is subjected to this solenoid controlled between the normally-closed contact of described switch element inside and the normally opened contact, and described metal clips one end is connected with the output of switch element;
The output of described switch element is connected with static impedance device element;
Described solenoid and reverse impulse absorption diode form parallel circuits, and the two ends of described parallel circuits are connected with collector electrode and the 4th power supply of the 3rd triode respectively;
The current input terminal of described the tenth resistance is connected with decoding deck, and current output terminal is connected with the base stage of the 3rd triode;
The current input terminal of described the 11 resistance is arranged on the base stage connecting circuit of current output terminal and the 3rd triode, and is connected with ground after the emitter parallel connection of described the 11 resistance and the 3rd triode.
9. according to each described movement shaven head current foldback circuit of claim 2～4, it is characterized in that: described delay driving circuit comprises delay chip and the 5th electric capacity; Wherein,
The input of described delay chip is connected with decoding deck, and described the 5th electric capacity one end is connected on the input and decoding deck connecting circuit of delay chip, and the other end is connected with ground;
The earth terminal of described delay chip is connected with ground, and the output of described delay chip is connected with on-off switch.
10. according to each described movement shaven head current foldback circuit of claim 2～4, it is characterized in that: described static impedance device element comprises the 13 resistance, the 6th electric capacity, filter inductance, static esd protection diode; Wherein,
Described filter inductance is arranged on the connecting circuit of on-off switch and power output end; the connecting circuit of described filter inductance and power output end is provided with first, second and the 3rd tie point; wherein; the current input terminal of described the 13 resistance, static esd protection diode and the 6th electric capacity is connected with first, second and the 3rd tie point respectively, and is connected with ground after the current output terminal parallel connection of described 13 resistance, static esd protection diode and the 6th electric capacity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220705096.8U CN203135403U (en) | 2012-12-18 | 2012-12-18 | Over-current protection circuit for loader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220705096.8U CN203135403U (en) | 2012-12-18 | 2012-12-18 | Over-current protection circuit for loader |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203135403U true CN203135403U (en) | 2013-08-14 |
Family
ID=48943343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201220705096.8U Expired - Fee Related CN203135403U (en) | 2012-12-18 | 2012-12-18 | Over-current protection circuit for loader |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203135403U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108375935A (en) * | 2018-03-23 | 2018-08-07 | 海华电子企业(中国)有限公司 | A kind of navigation radar transceiver servo-control system with overcurrent delay protection |
| WO2020140656A1 (en) * | 2018-12-30 | 2020-07-09 | 惠州三华工业有限公司 | Overcurrent protection circuit, and overcurrent protection system |
| CN112769093A (en) * | 2019-11-05 | 2021-05-07 | 杭州海康威视数字技术股份有限公司 | Current-limiting control circuit, chip and power supply |
| CN116068244A (en) * | 2023-03-07 | 2023-05-05 | 常州同惠电子股份有限公司 | Wide-range overcurrent detection protection circuit, protection method and device for power meter |
-
2012
- 2012-12-18 CN CN201220705096.8U patent/CN203135403U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108375935A (en) * | 2018-03-23 | 2018-08-07 | 海华电子企业(中国)有限公司 | A kind of navigation radar transceiver servo-control system with overcurrent delay protection |
| WO2020140656A1 (en) * | 2018-12-30 | 2020-07-09 | 惠州三华工业有限公司 | Overcurrent protection circuit, and overcurrent protection system |
| CN112769093A (en) * | 2019-11-05 | 2021-05-07 | 杭州海康威视数字技术股份有限公司 | Current-limiting control circuit, chip and power supply |
| CN112769093B (en) * | 2019-11-05 | 2023-12-29 | 杭州海康威视数字技术股份有限公司 | Current-limiting control circuit, chip and power supply |
| CN116068244A (en) * | 2023-03-07 | 2023-05-05 | 常州同惠电子股份有限公司 | Wide-range overcurrent detection protection circuit, protection method and device for power meter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203135403U (en) | Over-current protection circuit for loader | |
| CN103538481B (en) | The control system of electronlmobil and brake protection device | |
| CN204030681U (en) | Lithium ion cell charging current foldback circuit | |
| CN201966576U (en) | Load short circuit protection circuit | |
| CN205092599U (en) | Equalizing charge device of multisection battery | |
| CN104734123B (en) | Lithium battery intrinsic safe explosion-proof circuit | |
| CN201536254U (en) | Protector for power transformer | |
| CN202533526U (en) | General test circuit of switch sensor or solenoid valve | |
| CN102416881A (en) | Interlocking structure of battery packs | |
| CN202663372U (en) | Insulated gate bipolar transistor driving protector | |
| CN202749802U (en) | Circuit for protecting IGBT in output short-circuit state of frequency converter | |
| CN206743606U (en) | The LED illumination linear constant current drive circuit of absorbable leakage current | |
| CN203025235U (en) | Voltage state detection circuit of output channel | |
| CN201438681U (en) | Intelligent controller for solar power supplies | |
| CN202889312U (en) | Low power consumption low-voltage control relay with optical isolator | |
| CN202550940U (en) | Motor soft starting device | |
| CN105334368A (en) | Electrical self-check circuit for solenoid valve of aesthesia machine | |
| CN201877778U (en) | Overcurrent protection circuit of solar street lamp | |
| CN104535924A (en) | Relay state detection processing circuit and detection processing method of relay state detection processing circuit | |
| CN202712884U (en) | Battery connection detecting circuit and battery charger | |
| CN204696664U (en) | The output overvoltage undervoltage protection device of DC-DC power source | |
| CN203288934U (en) | Low-power semiconductor laser drive circuit | |
| CN204681082U (en) | A kind of electric tricycle charger IGBT current foldback circuit | |
| CN103091543B (en) | Current detection circuit, constant current circuit and battery charging and discharging protective system | |
| CN206618797U (en) | A kind of zero-crossing detection circuit of power line carrier |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130814 Termination date: 20211218 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |