CN209029903U - A kind of overcurrent and short-circuit protection circuit - Google Patents
A kind of overcurrent and short-circuit protection circuit Download PDFInfo
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- CN209029903U CN209029903U CN201822021844.0U CN201822021844U CN209029903U CN 209029903 U CN209029903 U CN 209029903U CN 201822021844 U CN201822021844 U CN 201822021844U CN 209029903 U CN209029903 U CN 209029903U
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Abstract
The utility model provides a kind of overcurrent and short-circuit protection circuit, belongs to electronic equipments technical field.This overcurrent and short-circuit protection circuit include: voltage sensor, for being connected in parallel on main performance loop output end to detect output voltage variation；Main switch, for being connected between power supply and main performance loop, and based on the received, switching signal controls the on-off of circuit between power supply and main performance loop；Monitoring module, signal input part are connected with voltage sensor, for receiving the voltage signal of voltage sensor feedback and being compared the voltage signal and preset voltage threshold, the output control signal control main switch power-off when voltage signal is lower than voltage threshold；Conversion module, the control signal for exporting monitoring module are converted to the available switching signal of main switch.This overcurrent and short-circuit protection circuit will not destroy the connection performance of outgoing route, help that the working efficiency of system is made to keep stablizing, and have stable self-recovering function.
Description
Technical field
The utility model belongs to field of circuit technology, is related to a kind of overcurrent and short-circuit protection circuit.
Background technique
In electronic product, the situation of output end overcurrent or short circuit is difficult to avoid that, for example user is accidentally touched with metal
Output end, output end meet water, etc., it is therefore desirable to output overcurrent and short circuit take necessary safeguard measure.Some is integrated
Output overcurrent and short circuit protection measures are carried inside circuit circuit, but the IC interior yet having does not configure this protection
Measure, this needs application scheme to pass through the peripheral circuit of auxiliary just to realize.
The method of the output overcurrent and short-circuit protection that generally use now, basic circuit working principle are defeated by monitoring
Electric current on outbound path checks the size of output electric current come what is realized in real time, when output electric current reaches some threshold value, determines
To meet output overcurrent or short circuit condition, to trigger output overcurrent or short circuit protection measures.The advantages of this method is applicable
Property is wide, theoretically, is all suitable for, but disadvantage is also very much, mainly has following to all application conditions:
(1) voltage parameter must be converted to by current parameters are exported with sampling resistor.
Because directly detection electric current is very inconvenient, after converting thereof into voltage signal, just can be carried out detection, compare etc.
Reason.But electric current is converted into voltage, must just a high-precision sampling resistor be used to be serially connected in outgoing route, in main work
A main switch is inserted into circuit, for cutting off main performance loop when output overcurrent or short circuit occurs, arriving in negative pole of output end
It is inserted into a sampling resistor between ground connection, gives the voltage signal of its bad student to Detection & Controling module, generates corresponding control
Signal, in the control signal for after converting (optional), generating controllable main switch.
This can lead to the problem of some column.Firstly, the selection of this resistance is inherently relatively difficult, if resistance value is too
Greatly, then voltage drop caused by resistance will be too high, energy consumption (resistance is a dissipative cell) is increased, system is reduced
Working efficiency；But if resistance value is too small, then the voltage signal converted is too small, this just needs very high-precision comparator and reference
Source judges to realize, increases cost.Due to the comparison signal of unilateral comparator be mostly over the ground for, so this sampling electricity
Resistance can only connect the ground terminal in output end, this results in the ground of output end and the ground potential of input terminal variant.
(2) it is difficult to realize self-recovering function.
It is self-healing to be meant that circuit restore to work normally automatically when output overcurrent or short circuit condition revocation.It is real
The where the shoe pinches of existing self-recovering function are: when output overcurrent or short circuit occurs, main switch is disconnected, due to input terminal no longer to
Output end provides energy, so output electric current is 0, this means that output overcurrent or short-circuit condition are not set up again, so master opens
It closing and is connected again, main performance loop is resumed work, but actual output overcurrent or short circuit condition do not cancel really, once master opens
Pass connects, input terminal gives output end offer energy, and system can enter output overcurrent or short-circuit condition again, is again switched off master and opens
It closes.It is switching repeatedly in this way as a result, system may not be able to be protected injury-free.It is able to satisfy the control signal of protection target, is answered
This is: the time for cutting off main switch is long, and the time for connecting main switch is very short.This signal, referred to as small duty cycle signals.
Since the integrated circuit for generating small duty cycle signals when sampled voltage is greater than reference value in the market is considerably less, need
Cumbersome circuit, the parameter being arranged meticulously go to complete, so being the thing of part headache.
Summary of the invention
The purpose of this utility model is to provide a kind of overcurrent and short-circuit protection circuit, circuit technology to be solved is asked
Topic is how to avoid circuit output end and input end grounding point is unequal and the periodicity of main switch is switched off and on repeatedly
The occurrence of.
The purpose of this utility model can be realized by the following technical scheme: a kind of overcurrent and short-circuit protection circuit are used for
It is connected with main performance loop to be protected to main performance loop characterized by comprising
Voltage sensor, for being connected in parallel on main performance loop output end to detect output voltage variation；
Main switch, for being connected between power supply and main performance loop, and based on the received switching signal control power supply and
The on-off of circuit between main performance loop；
Monitoring module, signal input part are connected with voltage sensor, and signal output end passes through conversion module and main switch
Connection, for receiving the voltage signal of voltage sensor feedback and being compared the voltage signal and preset voltage threshold,
The output control signal control main switch power-off when voltage signal is lower than voltage threshold；
Conversion module, the control signal for exporting monitoring module are converted to the available switching signal of main switch.
The principles of the present invention are as follows: when main performance loop output end overcurrent or short circuit, the voltage falling of output end,
Since voltage sensor is connected to the output end of main performance loop, the voltage signal of voltage sensor sampling also drops, and monitors mould
Block by determining output end overcurrent or short circuit after voltage signal and preset voltage threshold are compared, export control signal to
Main switch makes its circuit between main performance loop of cutting off the power, once main switch is cut off, then output end cannot come from
The energy of input terminal, voltage 0, this is equivalent to output and is still within overcurrent or short-circuit condition, therefore main switch can't be by again
It is secondary to connect, it generates the main switch as described in " current method " and is periodically switched off and on repeatedly.
In a kind of above-mentioned overcurrent and short-circuit protection circuit, the voltage sensor includes the resistance R1 and electricity being connected in series
It hinders after R2, resistance R1 and resistance R2 connect and the output end of the main performance loop is in parallel, between the resistance R1 and resistance R2
A signal wire is drawn to be connected with the signal input part of the monitoring module.
In a kind of above-mentioned overcurrent and short-circuit protection circuit, the main switch is P-channel enhancement type insulated-gate field-effect
Pipe Q2, grid connect the signal output end of conversion module, and source electrode connects positive pole, and drain electrode connects main performance loop input terminal.
In a kind of above-mentioned overcurrent and short-circuit protection circuit, the conversion module is N-channel reinforced insulation grid field effect
Should pipe Q3, drain electrode connects main switch as signal output end, and source electrode ground connection, grid connects the control signal output of monitoring module.
In a kind of above-mentioned overcurrent and short-circuit protection circuit, the monitoring module uses the chip of model DT6101
U2, pin VIN and pin EN are used to connection power input, and pin SW is for connecting conversion module, and pin FB is for connecting
Connect voltage detection module.
In a kind of above-mentioned overcurrent and short-circuit protection circuit, the monitoring module is also connected with pulse generating module, uses
In periodically generating reset instruction pulse to monitoring module, the control module issues control signal according to the reset instruction pulse
To the conversion module to control main switch closure.
Compared with prior art, the overcurrent of technical solutions of the utility model and short-circuit protection circuit have the advantage that
(1) it does not need to seal in resistance in outgoing route, destroys the connection performance of outgoing route, influence the work effect of system
Rate causes system end and the output unequal problem of terminal ground potential.
(2) make and break repeatedly of main switch is avoided, while realizing self-recovering function by recurrent pulses, it is relatively reliable resistance to
With.
Detailed description of the invention
Fig. 1 is the schematic diagram of overcurrent and short-circuit protection circuit in the utility model embodiment.
Fig. 2 is the circuit diagram of overcurrent and short-circuit protection circuit in the utility model embodiment.
Specific embodiment
It is specific embodiment of the utility model and in conjunction with attached drawing below, the technical solution of the utility model is made further
Description, but the utility model is not limited to these examples.
As shown in Figure 1, this overcurrent is used to connect with main performance loop to carry out main performance loop with short-circuit protection circuit
Protection comprising: voltage sensor, main switch, monitoring module and conversion module.Wherein, voltage sensor is connected in parallel on main work
Loop output is to detect output voltage variation；Main switch is connected between power supply and main performance loop, and open based on the received
OFF signal controls the on-off of circuit between power supply and main performance loop；Monitoring module, signal input part and voltage sensor connect
It connects, signal output end connect with main switch by conversion module, receives the voltage signal that voltage sensor is fed back and by the voltage
Signal and preset voltage threshold are compared, and when voltage signal is lower than voltage threshold, output control signal control main switch is disconnected
Electricity；The control signal that monitoring module exports is converted to the available switching signal of main switch by conversion module.
As shown in Fig. 2, specifically:
Main switch is P-channel enhancement type isolated gate FET Q2, and grid connects the signal output end of conversion module, source electrode
Positive pole is connect, drain electrode connects main performance loop input terminal.
Conversion module is N-channel reinforced insulation gate field-effect transistor Q3, and drain electrode connects main switch, source as signal output end
Pole ground connection, grid connect the control signal output of monitoring module.
Monitoring module is used to connection power input using the chip U2, pin VIN and pin EN of model DT6101
End；Pin SW is as control signal output, for connecting the grid of conversion module；Pin FB is used for as signal input part
Connect voltage detection module.
Voltage sensor includes returning after the resistance R1 and resistance R2 being connected in series, resistance R1 and resistance R2 connect with main work
The output end on road is in parallel, and a signal wire is drawn between resistance R1 and resistance R2 and is connected with the pin FB of monitoring module.
The cardinal principle of the utility model is as follows: when main performance loop output end overcurrent or short circuit, the voltage of output end
Drop, since voltage sensor is connected to the output end of main performance loop, the voltage signal of voltage sensor sampling also drops, supervises
Module is controlled by determining output end overcurrent or short circuit, output control letter after voltage signal and preset voltage threshold are compared
Number give main switch, make its circuit between main performance loop of cutting off the power, once main switch be cut off, then output end cannot get
Energy from input terminal, voltage 0, this is equivalent to output and is still within overcurrent or short-circuit condition, therefore main switch can't
It is connected again, generates the main switch in " current method " such as and be periodically switched off and on repeatedly.
In order to make this overcurrent and short-circuit protection circuit can be realized reliable and stable self-recovering function, in monitoring module
Pulse generating module is added, which can periodically generate reset instruction pulse to monitoring module, control module
It is issued after control signal is converted via conversion module according to the reset instruction pulse and is conveyed to main switch, control closing for main switch
It closes, realizes resuming work automatically for main performance loop.
The specific embodiments described herein are merely examples of the spirit of the present invention.The utility model institute
Belonging to those skilled in the art can make various modifications or additions to the described embodiments or using similar
Mode substitute, but without departing from the spirit of the present application or beyond the scope of the appended claims.
Claims (6)
1. a kind of overcurrent and short-circuit protection circuit are used to connect with main performance loop to protect main performance loop, special
Sign is, comprising:
Voltage sensor, for being connected in parallel on main performance loop output end to detect output voltage variation；
Main switch, for being connected between power supply and main performance loop, and switching signal control power supply and main work based on the received
Make the on-off of circuit between circuit；
Monitoring module, signal input part are connected with voltage sensor, and signal output end is connected by conversion module with main switch,
For receiving the voltage signal of voltage sensor feedback and being compared the voltage signal and preset voltage threshold, in voltage
Output control signal control main switch power-off when signal is lower than voltage threshold；
Conversion module, the control signal for exporting monitoring module are converted to the available switching signal of main switch.
2. a kind of overcurrent according to claim 1 and short-circuit protection circuit, which is characterized in that the voltage sensor includes
After the resistance R1 and resistance R2 being connected in series, resistance R1 and resistance R2 connect and the output end of the main performance loop is in parallel, described
A signal wire is drawn between resistance R1 and resistance R2 to be connected with the signal input part of the monitoring module.
3. a kind of overcurrent according to claim 1 or 2 and short-circuit protection circuit, which is characterized in that the main switch is P ditch
Road reinforced insulation gate field-effect transistor Q2, grid connect the signal output end of conversion module, and source electrode connects positive pole, and drain electrode meets master
Performance loop input terminal.
4. a kind of overcurrent according to claim 3 and short-circuit protection circuit, which is characterized in that the conversion module is N ditch
Road reinforced insulation gate field-effect transistor Q3, drain electrode connect main switch, source electrode ground connection as signal output end, and grid connects monitoring module
Control signal output.
5. a kind of overcurrent according to claim 4 and short-circuit protection circuit, which is characterized in that the monitoring module uses type
Number it is used to connection power input for the chip U2, pin VIN and pin EN of DT6101, pin SW is for connecting modulus of conversion
Block, pin FB is for connecting voltage detection module.
6. a kind of overcurrent according to claim 1 or 2 and short-circuit protection circuit, which is characterized in that the monitoring module is also
It is connected with pulse generating module, for periodically generating reset instruction pulse to monitoring module, the control module is multiple according to this
Bit instruction pulse issues control signal to the conversion module to control main switch closure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822021844.0U CN209029903U (en) | 2018-11-27 | 2018-11-27 | A kind of overcurrent and short-circuit protection circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822021844.0U CN209029903U (en) | 2018-11-27 | 2018-11-27 | A kind of overcurrent and short-circuit protection circuit |
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| CN209029903U true CN209029903U (en) | 2019-06-25 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109274061A (en) * | 2018-11-27 | 2019-01-25 | 道崇电子科技（嘉兴）有限公司 | A kind of overcurrent and short-circuit protection circuit |
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2018
- 2018-11-27 CN CN201822021844.0U patent/CN209029903U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109274061A (en) * | 2018-11-27 | 2019-01-25 | 道崇电子科技（嘉兴）有限公司 | A kind of overcurrent and short-circuit protection circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of utility model: An over current and short circuit protection circuit Effective date of registration: 20210519 Granted publication date: 20190625 Pledgee: Bank of Jiaxing science and technology branch of Limited by Share Ltd. Pledgor: DAOCHONG ELECTRONIC TECHNOLOGY (JIAXING) Co.,Ltd. Registration number: Y2021980003752 |
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| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| CP03 | Change of name, title or address |
Address after: 314001 rooms 303, 305 and 306, building 13, phase III, Chinese Academy of Sciences, No. 906, Asia Pacific Road, Daqiao Town, Nanhu District, Jiaxing City, Zhejiang Province Patentee after: Daochong Electronic Technology (Zhejiang) Co.,Ltd. Address before: 314006 room 508-1, building 16, No. 906, Asia Pacific Road, Nanhu District, Jiaxing City, Zhejiang Province (phase III of Chinese Academy of Sciences) Patentee before: DAOCHONG ELECTRONIC TECHNOLOGY (JIAXING) Co.,Ltd. |
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| CP03 | Change of name, title or address |