CN108418189B - Switch protecting circuit - Google Patents
Switch protecting circuit Download PDFInfo
- Publication number
- CN108418189B CN108418189B CN201810091133.2A CN201810091133A CN108418189B CN 108418189 B CN108418189 B CN 108418189B CN 201810091133 A CN201810091133 A CN 201810091133A CN 108418189 B CN108418189 B CN 108418189B
- Authority
- CN
- China
- Prior art keywords
- diode
- switch
- resistance
- circuit
- lower edge
- 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.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/22—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices
- H02H7/222—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices for switches
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
- H03K17/081—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
Landscapes
- Electronic Switches (AREA)
Abstract
The present invention provides a kind of switch protecting circuits, the switch protecting circuit includes rapidly switching off circuit and controllable switch, wherein: the circuit that rapidly switches off includes first diode, second diode, 3rd resistor, 4th resistance and the second capacitor, the anode of the first diode connects the anode of second diode and the first end of the 4th resistance, the second end of 4th resistance connects the output end of a lower edge switch, the cathode of the first diode couples the input terminal of the lower edge switch, the cathode of second diode connects the input terminal of the controllable switch, the output end of the controllable switch connects the input terminal of the lower edge switch；Described 3rd resistor one end connects the cathode of second diode, other end ground connection；Second capacitor one end connects the first end of the 4th resistance, other end ground connection.
Description
Technical field
The present invention relates to analog electronics technique field, in particular to a kind of switch protecting circuit.
Background technique
Fig. 1~2 are respectively switching mode and the low side driver circuit schematic diagram of PWM type, the two mainly by low side driving circuit and
Two parts of diagnostic circuit form.Low side driving circuit is the switching signal for working as master controller output or pwm signal S1 is height
Level, when being provided to the input terminal 11 of switch K1, the load end 12 of switch K1 is connected over the ground, and 10 one end of load connect power supply
Vbat, the other end 13 is since ground connection, load 10 are provided power, when S1 is low level, the K1 load end 12 of switch with
GND is disconnected, and switch K1 is during be conducting to disconnection, side circuit low for switching mode shown in FIG. 1, if load 10 is to feel
Property load, then needing lower edge switch clamper absorption inductor energy, (if lower edge switch ability not enough needs additional TVS, auxiliary is protected
Shield), until electric current is reduced to zero；Side circuit low for PWM type shown in Fig. 2, load 10 are typically all inductive load, at this time can be with
By diode D100 afterflow, guarantee that electric current will not be mutated.C1 is ESD Absorption Capacitance.
The failure of low side driving circuit mainly has SCB (load end 13 is shorted to power supply), the SCG (load end 13
It is shorted to ground) and OL (load end 13 is opened a way), for different switch fault states, diagnostic requirements are also different.
The diagnosis on low side is connected to node 12 by resistance using the AD mouth or I/O port of MCU, and Diagnostic Strategy is by judging MCU
AD mouth or I/O port sampled voltage.For the switching mode in Fig. 1, when low side driving circuit switch K1 is disconnected, pass through signal S4
Voltage is provided to master controller, and master controller diagnoses low side SCG failure and OL failure (fault-free according to the voltage magnitude of signal S4
When two resistance of the S4 between node 12 and ground to the partial pressure value of Vbat；If it is be shorted to ground, the low electricity that S4 is close to zero
It is flat；If it is open circuit, S4 is partial pressure value of three resistance to VDD)；When lower edge switch K1 is connected, pass through the port master controller S4
(S4 amplitude should be the low level close to ground at this time, but the load end 12 is shorted to power supply makes S4 for diagnosable low side SCB failure
For a branch pressure voltage).For the PWM type in Fig. 2, when low side driving circuit OFF state, i.e., low side driving circuit switch K1 is disconnected
After (loading the not switch off state in afterflow), master controller is provided to by signal S4 current potential, master controller is according to letter
The low side SCG failure of potential diagnostic and OL failure of number S4；Lower edge switch K1 conducting (low side driving circuit PWM state, i.e. K1 according to
Certain rule is alternately closed and turns off) when, pass through SCB failure, the SCG failure of the diagnosable low side output in the port master controller S4
With OL failure.Judge that the I/O port of MCU continues the low and high level variation of several PWM cycles to determine whether faulty presence.When adopting
When having low and high level variation in the sample period, it is judged as normal condition；If I/O port level is when continuing high, to be judged as in the sampling period
SCB failure occurs；If I/O port level is when continuing low, to be judged as and SCG failure or OL failure (SCG and OL occurs in the sampling period
Two failures cannot be distinguished).
Damage of the SCB failure to master controller in these three types of failures when low side on state is maximum, if really occurring
When SCB failure, diagnosis acknowledging time is that several milliseconds of even a few tens of milliseconds, short circuit currents during which can reach tens of amperes, millisecond
Heavy current impact more than rank has following risk: burning out lower edge switch, burns out PCB trace, is more than functional safety institute
It is required that other security risk problems for being caused of turn-off time.So for current Diagnostic Strategy, fault recognition and shutdown
Timeliness it is very poor, have damage controller risk.
Summary of the invention
The purpose of the present invention is to provide a kind of switch protecting circuits, are shorted to solving existing lower edge switch output end
The problem of power failure diagnosing overlong time.
In order to solve the above technical problems, the present invention provides a kind of switch protecting circuit, the switch protecting circuit includes fast
Fast breaking circuit and controllable switch, in which:
The circuit that rapidly switches off includes first diode, the second diode, 3rd resistor, the 4th resistance and the second electricity
Hold, the anode of the first diode connects the anode of second diode and the first end of the 4th resistance, described
The second end of 4th resistance connects the output end of a lower edge switch, and the cathode of the first diode couples the lower edge switch
Input terminal, the cathode of second diode connect the input terminal of the controllable switch, the output end connection of the controllable switch
The input terminal of the lower edge switch；
Described 3rd resistor one end connects the cathode of second diode, other end ground connection；
Second capacitor is in parallel with the 3rd resistor.
Optionally, in the switch protecting circuit,
One first control signal is provided to the input terminal of the lower edge switch, and the first control signal is the first level
When, the output end of the lower edge switch is second electrical level, when the first control signal is second electrical level, the lower edge switch
Output end ground connection, wherein the first level is lower than second electrical level.
Optionally, in the switch protecting circuit, when the controllable switch disconnects, the output of the controllable switch
For high-impedance state, when controllable switch closure, the output end ground connection of the controllable switch；
It is described when the first control signal is located at second electrical level for the second end of second electrical level and the 4th resistance
Second diode current flow, the controllable switch closure；
It is described when the first control signal is located at second electrical level for the second end of the first level and the 4th resistance
The shutdown of second diode, the controllable switch disconnect；
It is described when the first control signal is located at the first level for the second end of second electrical level and the 4th resistance
The shutdown of second diode, the controllable switch disconnect.
Optionally, in the switch protecting circuit, one load of switch protecting circuit connection, the of the load
One end connects main power source, and the second end of the load is grounded by first capacitor, and connects the output end of the lower edge switch；
The switch protecting circuit further includes second resistance, one end input of the second resistance the first control letter
Number, the other end connects the input terminal of the lower edge switch.
Optionally, in the switch protecting circuit, the circuit that rapidly switches off further includes AND gate circuit, in which:
One second control signal is provided to the first input end of the AND gate circuit；Second input terminal of the AND gate circuit
Connect the cathode of second diode；The output end of the AND gate circuit couples the input terminal of the controllable switch.
Optionally, in the switch protecting circuit, the first control signal is pulse-width signal.
Optionally, in the switch protecting circuit, the load further includes the 6th diode, the 6th diode
Anode connect the second end of the load, the cathode of the 6th diode connects the main power source.
Optionally, in the switch protecting circuit, the circuit that rapidly switches off further includes the 5th resistance, the 6th electricity
Resistance, third diode, the 4th diode and the 5th diode, in which:
The both ends of 5th resistance are separately connected the output end of the AND gate circuit and the input terminal of the controllable switch；
The both ends of 6th resistance be separately connected the lower edge switch output end and the AND gate circuit it is first defeated
Enter end；
The anode of the third diode connects the output end of the AND gate circuit, the cathode connection of the third diode
Second input terminal of the AND gate circuit；
The anode of 4th diode connects the first input end of the AND gate circuit, the cathode of the 4th diode
Connect a constant pressure source；
The anode of 5th diode connects the first input end of the AND gate circuit, the cathode of the 5th diode
Input the second control signal.
Optionally, in the switch protecting circuit, second capacitor, 3rd resistor, the 4th resistance and the two or two
The selection of pole pipe should meet t greater than the lower edge switch closing course time, in which:
Wherein, R=R3*R4/ (R3+R4), Ut=Vth, U0=0V, Us=(Vbat-Vf) * R3/ (R3+R4), if
(Vbat-Vf) * R3/ (R3+R4) >=5V, then US=5V, in which: Vth is the cut-in voltage or described and door of the controllable switch
The high-level threshold voltage of circuit, Vbat are main supply voltage value, and Vf is the conduction voltage drop of the second diode, and R3 is 3rd resistor
Resistance value, R4 be the 4th resistance resistance value, C be the second capacitor capacitance.
Optionally, in the switch protecting circuit, the electric conduction of the first diode and second diode
It presses equal.
In switch protecting circuit provided by the invention, the anode of first diode connects the anode of second diode
And the 4th resistance first end, the 4th resistance second end connection lower edge switch output end, the first diode
Cathode coupling lower edge switch input terminal, the cathode of second diode connects the input terminal of the controllable switch, and (Fig. 3 is fast
Fast breaking circuit) or the connection AND gate circuit the second input terminal (Fig. 4 rapidly switches off circuit), the output of the controllable switch
End connects the input terminal of the lower edge switch, and when there is SCB failure, i.e., the input terminal of lower edge switch is high level, and low side is opened
The output end of pass is but high level when should be low level, and C2 is started to charge at this time, until charging to opening for the input terminal more than K2
When opening high-level threshold (Fig. 4 rapidly switches off circuit) of threshold value (Fig. 3 rapidly switches off circuit) or the second input terminal of U1, controllably open
Pass is opened, and further makes lower edge switch input terminal approximately ground, prevents heavy current impact caused by SCB failure from leading to TCU's
Damage.
Further, by the setting to AND gate circuit, second control signal can be increased, to the switch after troubleshooting
Protection circuit is resetted.
The present invention by increase based on controllable switch low side output rapidly switch off circuit after, for work in SCB
Fault diagnosis processing shorten to Microsecond grade by Millisecond, avoids the damage to controller, while can also meet ISO26262 function
The strict demand of energy safety.
Detailed description of the invention
Fig. 1~2 are existing lower edge switch drive circuit schematic diagrams；
Fig. 3 is one embodiment of the invention lower edge switch drive circuit schematic diagram；
Fig. 4 is another embodiment of the present invention lower edge switch drive circuit schematic diagram.
Specific embodiment
Switch protecting circuit proposed by the present invention is described in further detail below in conjunction with the drawings and specific embodiments.Root
According to following explanation and claims, advantages and features of the invention will be become apparent from.It should be noted that attached drawing be all made of it is very simple
The form of change and use non-accurate ratio, only for the purpose of facilitating and clarifying the purpose of the embodiments of the invention.
Core of the invention thought is to provide a kind of switch protecting circuit, short to solve existing lower edge switch output end
The problem of road is to power failure diagnosing overlong time.
To realize above-mentioned thought, the present invention provides a kind of switch protecting circuit, the switch protecting circuit includes quick
Breaking circuit and controllable switch, in which: the circuit that rapidly switches off includes first diode, the second diode, 3rd resistor,
Four resistance and the second capacitor, the anode of the first diode connect the anode and the 4th resistance of second diode
First end, the second end of the 4th resistance connects the output end of a lower edge switch, the cathode coupling of the first diode
The input terminal of the lower edge switch, the cathode of second diode connects the input terminal of the controllable switch, and (Fig. 3 is rapidly switched off
Circuit) or the connection AND gate circuit the second input terminal (Fig. 4 rapidly switches off circuit), the output end connection of the controllable switch
The input terminal of the lower edge switch；Described 3rd resistor one end connects the cathode of second diode, other end ground connection；It is described
Second capacitor is in parallel with the 3rd resistor.
The present embodiment provides a kind of switch protecting circuits, as shown in figure 3, the switch protecting circuit includes rapidly switching off electricity
Road and controllable switch K2, in which: it is described rapidly switch off circuit include first diode D1, the second diode D2,3rd resistor R3,
4th resistance R4 and the second capacitor C2, the anode of the first diode D1 connect anode and the institute of the second diode D2
State the first end of the 4th resistance R4, the second end of the 4th resistance R4 connects the output end 12 of a lower edge switch K1, and described the
The cathode of one diode D1 couples the input terminal 11 of the lower edge switch K1, i.e., the input terminal of lower edge switch K1 is connected to by R2
The cathode of 11, the second diode D2 connect the input terminal of the controllable switch K2, and the output end of the controllable switch K2 connects
The input terminal 11 of the lower edge switch K1 is connect, the one end the 3rd resistor R3 connects the cathode of the second diode D2, another
End ground connection；Second capacitor is in parallel with the 3rd resistor.
Specifically, a first control signal S1 is provided to the lower edge switch K1's in the switch protecting circuit
Input terminal 11, when the first control signal S1 is the first level, the output end 12 of the lower edge switch K1 is second electrical level, institute
When to state first control signal S1 be second electrical level, the output end 12 of the lower edge switch K1 is grounded, wherein the first level is lower than the
Two level.Second electrical level in the present embodiment refers to high level, such as the value of VDD, the value of about 5V or so or Vbat, about 9~
16V or so, the first level refer to 0V or ground connection.When the controllable switch K2 is disconnected, the output of the controllable switch K2 is high resistant
The input terminal 11 of state, lower edge switch K1 keeps primary voltage, when controllable switch K2 closure, the output of the controllable switch K2
The input terminal 11 of end ground connection, lower edge switch K1 is grounded；High-impedance state is the generic term in digital circuit, refers to a kind of output of circuit
State, neither high level is also not low level, high-impedance state has no effect to the next stage circuit that it is connected, if using general-purpose
Table measures its current potential, then its current potential is determined by the current potential of next stage circuit.
It (is somebody's turn to do when the first control signal S1 is located at second electrical level for the second end of second electrical level and the 4th resistance R4
Current potential should be the first level, but due to there is SCB failure, is shorted to power supply at this, second electrical level occurs) when, described second
Diode D2 conducting, the controllable switch K2 closure, the output end ground connection of the controllable switch K2, the input terminal of lower edge switch K1
11 ground connection, even if the output end 12 of lower edge switch K1 is shorted to power supply at this time, also due to input terminal 11 has been turned off, it will not be to control
Device impacts；
When the first control signal S1 is located at second electrical level for the second end of the first level and the 4th resistance R4,
Second diode D2 shutdown, the controllable switch K2 are disconnected, which is that lower edge switch K1 is disconnected and normal situation, can
Control switch K2 will not impact the input terminal of lower edge switch K1；
When the first control signal S1 is located at the first level for the second end of second electrical level and the 4th resistance R,
The second diode D shutdown, the controllable switch K2 are disconnected, which is the feelings of lower edge switch K1 closure and normal work
Condition, controllable switch K2 will not impact the input terminal of lower edge switch K1.
Specifically, as shown in figure 3, one load 10 of switch protecting circuit connection, the first end connection of the load 10
Main power source Vbat, the second end of the load 10 is grounded by first capacitor C1, and connects the output end of the lower edge switch K1
12；The switch protecting circuit further includes second resistance R2, and one end of the second resistance R2 inputs the first control signal
S1, the other end connect the input terminal 11 of the lower edge switch K1.The first control signal S1 is output permanent High level at this time
Or continue low level switching signal.
Further, it as shown in figure 4, the present invention also provides the switch protecting circuit of another embodiment, is opened in described
It closes in protection circuit, the circuit that rapidly switches off further includes AND gate circuit U1, in which: a second control signal S2 is provided to described
The first input end of AND gate circuit U1；The second input terminal of the AND gate circuit U1 connects the cathode of the second diode D2；
The output end of the AND gate circuit U1 couples the input terminal of the controllable switch K2, i.e., is connected to the controllable switch K2 by R5
Input terminal.The first control signal S1 is pulse-width signal at this time.
Specifically, the load is also connected with one the 6th diode D6, the anode connection of the 6th diode D6 is described negative
10 second end is carried, the cathode of the 6th diode D6 connects the main power source Vbat.The one end second capacitor C2 connection
The second input terminal of the AND gate circuit U1, other end ground connection.The circuit that rapidly switches off further includes the 5th resistance R5, the 6th electricity
Hinder R6, third diode D3, the 4th diode D4 and the 5th diode D5, in which: the both ends of the 5th resistance R5 connect respectively
Connect the output end of the AND gate circuit U1 and the input terminal of the controllable switch K2；The both ends of the 6th resistance R6 are separately connected
The first input end of the output end 12 of the lower edge switch K1 and the AND gate circuit U1；The anode of the third diode D3 connects
The output end of the AND gate circuit U1 is connect, the cathode of the third diode D3 connects the second input of the AND gate circuit U1
End, once failure occurs, after output end exports high level, the output end of AND gate circuit is second defeated by it by third diode D3
Enter end to be locked on high level；The anode of the 4th diode D4 connects the first input end of the AND gate circuit U1, described
The cathode of 4th diode D4 connects a constant pressure source VDD and passes through the 4th diode D4's when the current potential of first input end is excessively high
Clamper, the current potential of first input end are maintained near power supply vdd voltage, prevent AND gate circuit due to input terminal excessive pressure damages；Institute
The anode for stating the 5th diode D5 connects the first input end of the AND gate circuit U1, the cathode input of the 5th diode D5
The second control signal S2, second control signal S2 keep high level under normal circumstances, when failure and trouble shooting
Afterwards, the second output terminal of master controller is needed to export low level second control signal S2, when second control signal S2 is low electricity
Usually, the current potential of the first input end of AND gate circuit is also low level, and only a diode higher than second control signal S2 is led
Be powered pressure, then AND gate circuit U1 restores to export low level again.
Further, the selection of second capacitor, 3rd resistor, the 4th resistance and the second diode should meet t and be greater than
The lower edge switch closing course time, in which:
Wherein, R=R3*R4/ (R3+R4), Ut=Vth, U0=0V, Us=(Vbat-Vf) * R3/ (R3+R4), if
(Vbat-Vf) * R3/ (R3+R4) >=5V, then US=5V, in which: Vth is the cut-in voltage or described and door of the controllable switch
The high-level threshold voltage of circuit, Vbat are main supply voltage value, and Vf is the conduction voltage drop of the second diode, and R3 is 3rd resistor
Resistance value, R4 be the 4th resistance resistance value, C be the second capacitor capacitance.
Meeting during the place for being easiest to go wrong in circuit design is lower edge switch K1 driving signal by low get higher
It is not in wrong diagnosis caused by " competition ", " competition " here refers to the output end electricity in K1 opening process due to lower edge switch
Pressure falls to low level by high level, while capacitor C2 is charged by the current potential of lower edge switch output end, and D1 is caused to connect with D2
The current potential at place is excessively high, thus before K1 closure, is first closed K2 and false triggering K1 the case where rapidly switching off.Specifically, working as K1
When starting to open, S1 is height, and the current potential at node 12 is lower by height, and the cathode of D2 is started to rise to capacitor C2 charging from 0V
Pressure, charging time seek according to the following formula:
T can be found out by above-mentioned formula, the time of lower edge switch conducting can obtain according to corresponding chip data, as long as
Guarantee that charge to the time t before controllable switch K2 is opened can avoid due to opening greater than the time of lower edge switch opening process experience
The wrong diagnosis problem that " competition " during opening is caused, choosing this time needs there are certain surplus, and this time
It is limited to the conducting voltage Vf of 3rd resistor R3, the 4th resistance R4, the second capacitor C2 and the second diode.
In addition, in the switch protecting circuit, in order to guarantee the accurate of circuit, the first diode and described
The conducting voltage of two diodes is equal, and when so that S1 being low level, the cathode of D2 is also low level；And S1 be high level when, D2
Cathode be not necessarily low level, specifically to see lower edge switch export situation.
In switch protecting circuit provided in this embodiment, the anode of first diode D1 connects the second diode D2
Anode and the 4th resistance R4 first end, the 4th resistance R4 second end connection lower edge switch K1 output end, institute
The input terminal of the cathode coupling lower edge switch K1 of first diode D1 is stated, the cathode connection of second diode is described controllably to open
The input terminal (Fig. 3 rapidly switches off circuit) of pass or the second input terminal (Fig. 4 rapidly switches off circuit) of the connection AND gate circuit, institute
The output end for stating controllable switch K2 connects the input terminal of the lower edge switch K1, when there is SCB failure, i.e. lower edge switch K1's
Input terminal is high level, and the output end of lower edge switch K1 is but high level when should be low level, and C2 is started to charge at this time, until filling
When electricity to the unlatching threshold value for the input terminal for being more than K2 or the high-level threshold of the second input terminal of U1, controllable switch is opened, into
One step makes lower edge switch input terminal approximately ground, prevents heavy current impact caused by SCB failure from leading to the damage of TCU.
Further, by the setting to AND gate circuit, second control signal can be increased, to the switch after troubleshooting
Protection circuit is resetted.
The present invention by increase based on controllable switch K2 low side output rapidly switch off circuit after, for work in
The processing of SCB fault diagnosis shorten to Microsecond grade by Millisecond, avoids the damage to controller, while can also meet ISO26262
The strict demand of functional safety.
The second end of one load 10 of the connection of output end 12 of the lower edge switch K1, the first end of the load 10 connect electricity
Pond power supply Vbat, power supply Vbat are that load 10 provides power input, and constant pressure source VDD is 5V voltage source.
After rapidly switching off circuit by low side of the increase based on operational amplifier, when working for switching signal and PWM
The processing of SCB fault diagnosis shorten to Microsecond grade by former Millisecond, avoids the damage to master controller, while can also meet
The strict demand of ISO26262 functional safety.
When SCB failure occurs for the low side output of PWM type driving circuit described in Fig. 4, it can trigger and rapidly switch off and protect
The state of failure latching is held, master controller can control the level state of signal S3 by third to monitor whether to occur SCB event
Barrier.After failure vanishes, master controller can export low level by S2 and be resetted, and be drawn at this time with the second input pin of door U1
It is low, it realizes fault unlock, controllable switch K2 can be turned off, low side driving continues to work normally.
To sum up, the various configuration of switch protecting circuit is described in detail in above-described embodiment, and certainly, the present invention includes
But be not limited in above-mentioned implementation cited configuration, it is any converted on the basis of configuration provided by the above embodiment in
Hold, belongs to the range that the present invention is protected.Those skilled in the art can draw inferences about other cases from one instance according to the content of above-described embodiment.
Foregoing description is only the description to present pre-ferred embodiments, not to any restriction of the scope of the invention, this hair
Any change, the modification that the those of ordinary skill in bright field does according to the disclosure above content, belong to the protection of claims
Range.
Claims (11)
1. a kind of switch protecting circuit, which is characterized in that the switch protecting circuit includes rapidly switching off circuit and controllable switch,
Wherein:
The circuit that rapidly switches off includes first diode, the second diode, 3rd resistor, the 4th resistance and the second capacitor,
The anode of the first diode connects the anode of second diode and the first end of the 4th resistance, and the described 4th
The second end of resistance connects the output end of a lower edge switch, and the cathode of the first diode couples the input of the lower edge switch
End, the cathode of second diode connect the input terminal of the controllable switch, described in the output end connection of the controllable switch
The input terminal of lower edge switch；
Described 3rd resistor one end connects the cathode of second diode, other end ground connection；
Second capacitor is in parallel with the 3rd resistor.
2. switch protecting circuit as described in claim 1, which is characterized in that
Under normal circumstances, a first control signal is provided to the input terminal of the lower edge switch, and the first control signal is
When the first level, the output end of the lower edge switch is second electrical level, described low when the first control signal is second electrical level
The output end ground connection of side switch, wherein the first level is lower than second electrical level.
3. switch protecting circuit as claimed in claim 2, which is characterized in that described controllable when the controllable switch disconnects
The output of switch is high-impedance state, when controllable switch closure, the output end ground connection of the controllable switch；
When the first control signal is located at second electrical level for the second end of second electrical level and the 4th resistance, described second
Diode current flow, the controllable switch closure；
When the first control signal is located at second electrical level for the second end of the first level and the 4th resistance, described second
Diode shutdown, the controllable switch disconnect；
When the first control signal is located at the first level for the second end of second electrical level and the 4th resistance, described second
Diode shutdown, the controllable switch disconnect.
4. switch protecting circuit as claimed in claim 3, which is characterized in that one load of switch protecting circuit connection, institute
The first end connection main power source of load is stated, the second end of the load is grounded by first capacitor, and connects the lower edge switch
Output end；
The switch protecting circuit further includes second resistance, and one end of the second resistance inputs the first control signal, separately
One end connects the input terminal of the lower edge switch.
5. switch protecting circuit as claimed in claim 4, which is characterized in that it is described rapidly switch off circuit further include and door electricity
Road, in which:
One second control signal is provided to the first input end of the AND gate circuit；Second input terminal of the AND gate circuit connects
The cathode of second diode；The output end of the AND gate circuit couples the input terminal of the controllable switch.
6. switch protecting circuit as claimed in claim 5, which is characterized in that the first control signal is pulsewidth modulation letter
Number.
7. switch protecting circuit as claimed in claim 5, which is characterized in that the load further includes the 6th diode, described
The anode of 6th diode connects the second end of the load, and the cathode of the 6th diode connects the main power source.
8. switch protecting circuit as claimed in claim 5, which is characterized in that the circuit that rapidly switches off further includes the 5th electricity
Resistance, the 6th resistance, third diode, the 4th diode and the 5th diode, in which:
The both ends of 5th resistance are separately connected the output end of the AND gate circuit and the input terminal of the controllable switch；
The both ends of 6th resistance are separately connected the output end of the lower edge switch and the first input end of the AND gate circuit；
The anode of the third diode connects the output end of the AND gate circuit, described in the cathode connection of the third diode
Second input terminal of AND gate circuit；
The anode of 4th diode connects the first input end of the AND gate circuit, the cathode connection of the 4th diode
One constant pressure source；
The anode of 5th diode connects the first input end of the AND gate circuit, the cathode input of the 5th diode
The second control signal.
9. switch protecting circuit as claimed in claim 3, which is characterized in that second capacitor, 3rd resistor, the 4th resistance
Selection with the second diode should meet t greater than the lower edge switch closing course time, in which:
Wherein, R=R3*R4/ (R3+R4), Ut=Vth, U0=0V, Us=(Vbat-Vf) * R3/ (R3+R4), if (Vbat-Vf) *
R3/ (R3+R4) >=5V, then Us=5V, in which: Vth is the cut-in voltage of the controllable switch, and Vbat is main supply voltage value,
Vf is the conduction voltage drop of the second diode, and R3 is the resistance value of 3rd resistor, and R4 is the resistance value of the 4th resistance, and C is the second capacitor
Capacitance.
10. switch protecting circuit as claimed in claim 5, which is characterized in that second capacitor, 3rd resistor, the 4th electricity
Resistance and the selection of the second diode should meet t greater than the lower edge switch closing course time, in which:
Wherein, R=R3*R4/ (R3+R4), Ut=Vth, U0=0V, Us=(Vbat-Vf) * R3/ (R3+R4), if (Vbat-Vf) *
R3/ (R3+R4) >=5V, then Us=5V, in which: Vth is the high-level threshold voltage of the AND gate circuit, and Vbat is main power source electricity
Pressure value, Vf are the conduction voltage drop of the second diode, and R3 is the resistance value of 3rd resistor, and R4 is the resistance value of the 4th resistance, and C is the second electricity
The capacitance of appearance.
11. switch protecting circuit as described in claim 1, which is characterized in that the first diode and the two or two pole
The conducting voltage of pipe is equal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810091133.2A CN108418189B (en) | 2018-01-30 | 2018-01-30 | Switch protecting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810091133.2A CN108418189B (en) | 2018-01-30 | 2018-01-30 | Switch protecting circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108418189A CN108418189A (en) | 2018-08-17 |
| CN108418189B true CN108418189B (en) | 2019-11-22 |
Family
ID=63126653
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810091133.2A Active CN108418189B (en) | 2018-01-30 | 2018-01-30 | Switch protecting circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108418189B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202042892U (en) * | 2011-04-06 | 2011-11-16 | 浙江001集团有限公司 | Switch protecting circuit |
| CN202503267U (en) * | 2012-03-13 | 2012-10-24 | 中国矿业大学 | Intrinsic safety type output short circuit protection device of high power switch converter |
| CN103683258A (en) * | 2013-11-28 | 2014-03-26 | 成都市宏山科技有限公司 | Power interface protecting circuit applicable to mobile equipment |
| CN204087034U (en) * | 2014-08-07 | 2015-01-07 | 广州海格通信集团股份有限公司 | There is the Anti-surging power switch protection circuit of over-voltage protecting function |
| CN204089759U (en) * | 2014-09-12 | 2015-01-07 | 叶良地 | High-frequency power device switch protecting circuit |
-
2018
- 2018-01-30 CN CN201810091133.2A patent/CN108418189B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202042892U (en) * | 2011-04-06 | 2011-11-16 | 浙江001集团有限公司 | Switch protecting circuit |
| CN202503267U (en) * | 2012-03-13 | 2012-10-24 | 中国矿业大学 | Intrinsic safety type output short circuit protection device of high power switch converter |
| CN103683258A (en) * | 2013-11-28 | 2014-03-26 | 成都市宏山科技有限公司 | Power interface protecting circuit applicable to mobile equipment |
| CN204087034U (en) * | 2014-08-07 | 2015-01-07 | 广州海格通信集团股份有限公司 | There is the Anti-surging power switch protection circuit of over-voltage protecting function |
| CN204089759U (en) * | 2014-09-12 | 2015-01-07 | 叶良地 | High-frequency power device switch protecting circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108418189A (en) | 2018-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2369725B1 (en) | Short circuiting unit | |
| CN103069530B (en) | The DC load cut-off catalyst of quasiconductor auxiliary | |
| US8031449B2 (en) | Fast-responding short circuit protection system with self-reset for use in circuit supplied by DC power | |
| CN106099864A (en) | The short-circuit protection method of a kind of IGBT device for power switching and circuit thereof | |
| CN208174241U (en) | A kind of leakage protection circuit | |
| CN104904114B (en) | Method and apparatus for monitoring photovoltaic apparatus | |
| CN104040819B (en) | Diagnosable reverse-voltage protection for high power load | |
| KR20140036233A (en) | Apparatus and method for connecting multiple-voltage onboard power supply systems | |
| DE102011016532A1 (en) | Charging device for battery of motor vehicle, has charging unit for charging battery, and alternating current inputs of charging unit | |
| CN104253410B (en) | Overvoltage breakdown preventing type input-stage ESD (Electronic Static Discharge) protection circuit | |
| CN110336250A (en) | A kind of soft protection circuit of the hardware of IGBT multiplexing functions | |
| CN100426646C (en) | Inverter device | |
| CN106771784B (en) | For diagnosing the circuit and method of load status | |
| CN209659145U (en) | A kind of electrical integrated protection circuit of charge and discharge for bidirectional DC power supply | |
| WO2023004952A1 (en) | Vehicle-mounted power supply circuit, and vehicle | |
| CN106896755A (en) | The load driving circuits of automobile-used single low side control | |
| CN108418189B (en) | Switch protecting circuit | |
| CN107839508A (en) | A kind of charging electric vehicle pipette tips electronic lock control device and a kind of electrical lock apparatus | |
| CN107965570B (en) | AT selector solenoid valve control and diagnosis protection circuit | |
| CN207910446U (en) | Switch protecting circuit | |
| CN111880088A (en) | Relay bilateral control and diagnosis circuit and method and battery management system | |
| CN101378226A (en) | Power source converter with diode opened circuit protection mechanism and pulse-width modulation controller thereof | |
| CN206585316U (en) | A kind of HVDC energy with control feedback is released control circuit | |
| CN101958533A (en) | Current sensing resistor short circuit protection device and method for isolated power supply | |
| CN108173248A (en) | Switch protecting circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |