CN110350473A - A kind of control circuit, method and device - Google Patents
A kind of control circuit, method and device Download PDFInfo
- Publication number
- CN110350473A CN110350473A CN201810290854.6A CN201810290854A CN110350473A CN 110350473 A CN110350473 A CN 110350473A CN 201810290854 A CN201810290854 A CN 201810290854A CN 110350473 A CN110350473 A CN 110350473A
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- Prior art keywords
- loudspeaker
- voltage
- switch
- comparator
- cathode
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/20—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage
Abstract
The embodiment of the invention provides a kind of control circuit, method and device, the control circuit includes: overvoltage crowbar, and the overvoltage crowbar includes comparator and switch, and the switch is coupled between loudspeaker and the front stage circuits of the overvoltage crowbar；The comparator is coupled to the voltage of acquisition loudspeaker compared with received reference voltage, and when the voltage of the loudspeaker is more than or equal to the reference voltage, and control switch disconnects the communication line of the front stage circuits and the loudspeaker.In this way, by disconnecting the communication line of front stage circuits and loudspeaker, playing the effect of protection loudspeaker safety when loudspeaker is in overvoltage condition.
Description
Technical field
The present invention relates to electronic technology, espespecially a kind of control circuit, method and device.
Background technique
Loudspeaker (Speaker, SPK) is used as electro-acoustic transducing device, is the nucleus module of car audio system.In automobile sound
In acoustic system, there may be the abnormal conditions such as over-voltage, short circuit, open circuit for loudspeaker, so not only influence the normal work of loudspeaker
Make, it is also possible to loudspeaker be caused to overheat or directly damage loudspeaker etc..
Currently, in vehicle-mounted Speaker protection mechanism, in addition to insertion offset detector is come other than carrying out protection loudspeaker safety,
There are no other effective solutions.
Summary of the invention
In view of this, the embodiment of the invention provides a kind of control circuits, comprising: overvoltage crowbar, the over-voltage are protected
Protection circuit includes comparator and switch, and the switch is coupled between loudspeaker and the front stage circuits of the overvoltage crowbar；
The comparator is coupled to the voltage of acquisition loudspeaker compared with received reference voltage, and works as the loudspeaker
Voltage be more than or equal to the reference voltage when, control switch disconnects the communication line of the front stage circuits and the loudspeaker.
Above-mentioned technical proposal, when loudspeaker is in overvoltage condition, by the communication line for disconnecting front stage circuits and loudspeaker
The effect of protection loudspeaker safety is played on road.
The embodiment of the invention also provides a kind of control methods, comprising:
When needing to carry out loudspeaker status detection, judge whether loudspeaker is in overvoltage condition；
When loudspeaker is not at overvoltage condition, enable signal is sent to detection circuit and is read by the detection circuit
The voltage or the voltage in anode circuit of loudspeaker electrode line road, to judge the state of loudspeaker.
Above-mentioned technical proposal can according to need in timing or in real time acquisition loudspeaker anode route or anode circuit
Voltage find loudspeaker faults in time to judge the state of loudspeaker.
The embodiment of the invention also provides a kind control device, described device includes: memory, processor and is stored in
On the memory and the program that can run on the processor, described program realize above-mentioned control when being executed by the processor
Method processed.
The embodiment of the invention also provides a kind of electronic equipment, above-mentioned control circuit further includes controller, the controller
It is configured as executing above-mentioned control method.
The embodiment of the invention also provides a kind of computer readable storage medium for being stored with computer executable instructions, institutes
It states computer executable instructions to be performed, realizes above-mentioned control method.
Other features and advantages of the present invention will be illustrated in the following description, also, partly becomes from specification
It obtains it is clear that understand through the implementation of the invention.The objectives and other advantages of the invention can be by specification, right
Specifically noted structure is achieved and obtained in claim and attached drawing.
Detailed description of the invention
Attached drawing is used to provide to further understand technical solution of the present invention, and constitutes part of specification, with this
The embodiment of application technical solution for explaining the present invention together, does not constitute the limitation to technical solution of the present invention.
Fig. 1 is the structural schematic diagram for the control circuit that the embodiment of the present invention one provides；
Fig. 2 is the block schematic illustration of overvoltage crowbar provided by Embodiment 2 of the present invention；
Fig. 3 is the circuit diagram of overvoltage crowbar provided by Embodiment 2 of the present invention；
Fig. 4 is the block schematic illustration for the detection circuit that the embodiment of the present invention three provides；
Fig. 5 is the circuit diagram for the detection circuit that the embodiment of the present invention three provides；
Fig. 6 is the structural block diagram for the car audio system that the embodiment of the present invention four provides；
Fig. 7 is overvoltage crowbar structural schematic diagram involved in the embodiment of the present invention four；
Fig. 8 is the flow diagram for the control method that the embodiment of the present invention five provides；
Fig. 9 is a kind of protection of loudspeaker and condition detection method flow diagram that the embodiment of the present invention six provides.
Specific embodiment
To make the objectives, technical solutions, and advantages of the present invention clearer, below in conjunction with attached drawing to the present invention
Embodiment be described in detail.It should be noted that in the absence of conflict, in the embodiment and embodiment in the application
Feature can mutual any combination.
Step shown in the flowchart of the accompanying drawings can be in a computer system such as a set of computer executable instructions
It executes.Also, although logical order is shown in flow charts, and it in some cases, can be to be different from herein suitable
Sequence executes the step of shown and/or description.
Loudspeaker can be placed under the risk to overheat or directly be damaged loudspeaker by abnormal offset.The relevant technologies
In, it can be embedded in offset detection function in power of vehicle amplifier apparatus, if detecting offset, issue loudspeaker protection
Control signal or order.But firstly, offset detection protection mechanism can only be protected in the case where loudspeaker has abnormal offset scene
The safety of loudspeaker, and cannot when loudspeaker is in overvoltage condition automatic protection loudspeaker safety, loudspeaking can not be detected
The short circuit of device, off state.Secondly, offset detection protection mechanism necessarily requires the control unit in car audio system, such as
MCU (micro-control unit, Microcontroller Unit) opens audio-frequency power amplifier according to sequence appropriate, if MCU
Amplifier is directly opened into play mode, loudspeaker in the case where not for making enough setting times of amplifier stability
Protection mechanism may not work.
Also, automotive interior electronic module and load are numerous, together form a complicated electronic environment each other.Each vapour
It between vehicle electronic module is connected by harness, on the interface of modular connector, it is understood that there may be different states.Typically
Automobile battery voltage range is 9V to 16V, and when tail-off, the nominal voltage of automobile batteries is 12V；When engine operation,
Cell voltage is in 14.4V or so.But under different condition, transient voltage may also reach ± 100V.Excessively high transient voltage can
It can make each electronic module operation irregularity, or even damage.Since the electronic control unit of automotive interior is more and more, each electronic control unit
Volume of transmitted data is also incremented by multiple, this requires automotive wire bundle to have more good information transfer function, with that is, also resulting in
The design of automotive wire bundle becomes increasingly complex.The automobile more for electrical equipment, automotive line bunch are more and random.In production test
In journey even in user's use process, mixed insertion, misplug or harness damage so as to cause short circuit, open circuit may all make vapour
The damage of vehicle interior electronic module, or even will affect vehicle circuitry system, threaten driving safety.
Based on this, present applicant proposes a kind of control circuits, method and device, can be when loudspeaker is in overvoltage condition
Protect the safety of loudspeaker.More it is possible to further the state for detecting loudspeaker, the failure of loudspeaker is determined in time and is determined
Position failure cause.Application scheme is described in detail below with reference to specific embodiment.
Embodiment one
Fig. 1 is the structural schematic diagram for the control circuit that the embodiment of the present invention one provides；As shown in Figure 1, the control circuit packet
Overvoltage crowbar is included, the overvoltage crowbar includes comparator and switch, and the switch is coupled in loudspeaker and the mistake
Between the front stage circuits of voltage protection circuit；
The comparator is coupled to the voltage of acquisition loudspeaker compared with received reference voltage, and works as the loudspeaker
Voltage when being more than or equal to the reference voltage, control switch is disconnected to disconnect the communication of the front stage circuits and the loudspeaker
Route.
In this way, when that is, loudspeaker is in overvoltage condition, disconnecting prime when loudspeaker voltage is more than or equal to the reference voltage
The effect of protection loudspeaker safety is played in the connection of circuit and loudspeaker；The front stage circuits include power amplification circuit, or
Other various circuits being connect with loudspeaker.
In this present embodiment, only detection loudspeaker cathode voltage whether can be more than or equal to its reference voltage or only detect
Whether loudspeaker cathode voltage is more than or equal to its reference voltage to judge whether loudspeaker is in overvoltage condition.But loudspeaker is just
Cathode is likely to that there are over-voltages, therefore is described in detail for detecting loudspeaker anode and cathode simultaneously below:
Specifically, the comparator includes first comparator and the second comparator, the switch include first switch and
Second switch, the output end of the first comparator couple first switch, and the output end coupling second of second comparator is opened
It closes；
The input terminal of the first comparator couples the anode of the loudspeaker to acquire cathode voltage and receive the first ginseng
Voltage is examined, when the cathode voltage is more than or equal to first reference voltage, the first comparator is to the first switch
Output disconnects control signal；
The input terminal of second comparator couples the cathode of the loudspeaker to acquire cathode voltage and receive the second ginseng
Voltage is examined, when the cathode voltage is more than or equal to second reference voltage, second comparator is to the second switch
Output disconnects control signal.
Wherein, the first switch and the second switch can be initially set on state.Controlling signal can be
High level or low level, the first switch and the second switch can be set to when receiving low level in disconnection shape
State, and it is in the conductive state when receiving high level.When first comparator judges that the cathode voltage is more than or equal to described the
When one reference voltage, low level is exported to first switch to disconnect first switch, and when the cathode voltage is less than described first
When reference voltage, to first switch output high level first switch is connected.Similarly, when the second comparator judges the negative electricity
When pressure is more than or equal to second reference voltage, low level is exported to disconnect second switch to second switch, and work as the cathode
When voltage is less than second reference voltage, to second switch output high level second switch is connected.Certainly, art technology
Personnel, which can according to need, is arranged different rules, is disconnected or is connected with control switch, Lai Shixian turns off or on prime
The communication line of circuit and loudspeaker.As long as in this way, loudspeaker anode or cathode it is any be in overvoltage condition when, disconnect it
Corresponding switch plays the effect of protection loudspeaker safety.
In this present embodiment, the output end of the first comparator and second comparator also respectively with controller coupling
It connects；
When the cathode voltage is more than or equal to first reference voltage, the first comparator is defeated to the controller
Over-voltage identification signal out；
When the cathode voltage is more than or equal to second reference voltage, second comparator is defeated to the controller
Over-voltage identification signal out.
Wherein, by taking first comparator and first switch as an example, the over-voltage identification signal can be effective for low level.It is described
The output end of first comparator is both couple to first switch, is also coupled to a pin of controller, for example is couple to certain of MCU
On one GPIO pin.When the cathode voltage is more than or equal to first reference voltage, the output end of the first comparator
Low level is exported, which receives low level and be in an off state, which receives low level, and controller is sentenced
Disconnected loudspeaker is in overvoltage condition.
Once the controller can be circuit system in this way, loudspeaker, which is in overvoltage condition, can be reported to controller
Microcontroller (or single-chip microcontroller) or CPU or digital signal processor DSP (Digital Signal
) or Field Programmable Logic Array FPGA (Field-Programmable Gate Array) etc. Processing.Below
It is illustrated so that controller is MCU as an example, but is not limited to MCU.
In this present embodiment, over-voltage identification signal can be reported to controller by AND gate circuit by two comparators, institute
Stating AND gate circuit can be made of two diodes, such as be connected to MCU's after the cathode of two diodes is linked together
On a certain pin, which just constitutes AND gate circuit.The a certain pin of the MCU can be GPIO pin, such as nothing
The GPIO is high level when over-voltage identification signal, when any one comparator output overvoltage identification signal (low level is effective),
GPIO can be pulled low, and MCU is to capture the over-voltage identification signal.
In this present embodiment, to play on-off action, switch can have the member of on-off action for NMOS tube, PMOS tube etc.
Device.Compare to play the role of voltage, comparator there can be electricity for single voltage limit comparator, dual-threshold voltage comparator etc.
Component of the pressure ratio compared with effect.
In the present embodiment, it is preferable that include the first NMOS tube with the first switch, the second switch includes second
NMOS tube, the first comparator and second comparator are to be described in detail for single voltage limit comparator:
Specifically, the output end of the first comparator is coupled to the first NMOS tube, an input terminal is coupled to loudspeaking
The positive cathode voltage to acquire loudspeaker of device, another input terminal receive first reference voltage, when the anode electricity
When pressure is more than or equal to first reference voltage, the first comparator is exported to the first NMOS tube disconnects control signal；
The output end of second comparator is coupled to the second NMOS tube, an input terminal be coupled to the cathode of loudspeaker with
Cathode voltage is acquired, another input terminal receives second reference voltage, when the cathode voltage is more than or equal to described second
When reference voltage, second comparator, which controls to export to the second NMOS tube, disconnects control signal.
Wherein, the disconnection control signal can be effective for low level.
Wherein, the G of first NMOS tube can extremely couple the output end of first comparator, and the pole S is coupled to front stage circuits
And the pole D coupling loudspeaker anode.The G of second NMOS tube can extremely couple the output end of the second comparator, before the coupling of the pole S
Grade circuit and D grades of coupling loudspeaker cathode.
In this present embodiment, control circuit further include: third switchs (VT1), and the third switch couples the over-voltage
Protect the switch of circuit；
The third switch disconnects control signal for receiving control signal and exporting to the switch.
The switch of the overvoltage crowbar can both be controlled by comparator and disconnect or be connected, can also be directly by controller
Control disconnects or conducting.
Specifically, the first switch and the second switch can be switched by third and be coupled with controller, it is described
Third switch disconnects control signal for receiving control signal from controller and exporting to the switch of the overvoltage crowbar,
Disconnect the communication line of the front stage circuits and the loudspeaker.By taking controller controls and disconnects first switch as an example, the control
Signal can be high level.Third switchgear distribution is in the conductive state after receiving high level from controller, and to first switch
Low level is exported, first switch is disconnected.Controller control disconnection second switch process is similar to above, repeats no more.
Specifically, third switch can be also used for receiving control signal from controller and to the overvoltage protection electricity
The switch on road exports conductivity control signal, and the communication line of the front stage circuits and the loudspeaker is connected.With controller control
For system conducting first switch: the control signal can be low level, and third switchgear distribution is to receive low level from controller
After be in an off state, and to first switch export high level, be connected first switch.Controller control conducting second switch process
It is similar to above, it repeats no more.
Wherein, the control of the control signal and comparator that switch while can receive controller of the overvoltage crowbar
Signal, the two control between signals and are not present control hazard, because switch can be received the control letter that controller exports
Number route and receive the route of control signal of comparator output and be set together, be described as follows by taking first switch as an example: when
Controller by third switch to first switch export low level when, if it is that high level (is raised that first comparator exports at this time
Sound device is not at overvoltage condition), low level can drag down high level, and first switch is received to remain as low level；Work as controller
By third switch to first switch export high level when, if it is that (loudspeaker was in low level that comparator exports at this time
Pressure condition), high level can not drag down low level, and first switch is received to remain as low level.Second switch receives control signal
Process it is similar to above, repeat no more.As shown in Figure 1, the control circuit not only includes overvoltage crowbar, can also include
Detection circuit；
The detection circuit is coupled with supply voltage and loudspeaker anode and cathode respectively；
The detection circuit is received enable signal and is connected the anode of supply voltage and loudspeaker based on the enable signal
And it is grounded the cathode of loudspeaker, and the voltage of output loudspeaker electrode line road.It is enabled alternatively, the detection circuit receives
Signal simultaneously connects the cathode of supply voltage and loudspeaker based on the enable signal and makes the plus earth of loudspeaker, and output
Voltage in loudspeaker anode circuit.
In this present embodiment, detection circuit can receive enable signal from controller, and just to controller output loudspeaker
Voltage on polar curve road or anode circuit.
Specifically, detection circuit can couple the ADC pin of controller, to controller export loudspeaker anode route or
Voltage in person's anode circuit.In this way, controller can according to need timing or in real time acquisition loudspeaker anode route or
Voltage in anode circuit finds loudspeaker faults to judge the state of loudspeaker in time.The loudspeaker status includes short
Road, open circuit (open circuit) etc..
Before carrying out loudspeaker status detection, controller switchs the switch into the overvoltage crowbar by third
Output disconnects control signal and is reached with disconnecting the communication line between loudspeaker and the front stage circuits of the overvoltage crowbar
The effect of isolation detection circuit and front stage circuits.The front stage circuits of the loudspeaker include power amplification circuit or other are logical
Cross the circuit that overvoltage crowbar is connect with loudspeaker.
Specifically, controller first determines whether loudspeaker is in overvoltage condition, if be in, without in next step
Movement, i.e., the switch that no longer control turns off the overvoltage crowbar also do not enable detection circuit；If be not at, controller
Control disconnects the switch of overvoltage crowbar and enabled detection circuit, to detect the state of loudspeaker.
In this present embodiment, controller switchs the pin of output control signal to third and exports enabled letter to detection circuit
Number pin can be the same pin, be also possible to different pins.
Specifically, when controller switchs the pin of output control signal to third and exports enable signal to detection circuit
Pin when being the same pin, the control signal and the enable signal are the same signals, for example, the signal is high level
When, third switch is configured as receiving in the conductive state when high level and exports low level i.e. to the switch of overvoltage crowbar
Disconnect control signal；Meanwhile detection circuit is configured as reception high level and is in enabled state.Those skilled in the art can root
According to needing to carry out other settings, for example, will control signal and enable signal to be set as low level effective.
Specifically, when controller switchs the pin of output control signal to third and exports enable signal to detection circuit
Pin when not being the same pin, controller switchs output control signal to third respectively, and enabled to detection circuit output
Signal；Or controller is no longer switched by third, but directly exported to the switch of overvoltage crowbar by a pin
Control signal is disconnected, and exports enable signal by another pin and to detection circuit.
In this present embodiment, after terminating detection loudspeaker status, controller also exports disabling signal to detection circuit, disconnects
Supply voltage and loudspeaker anode between connection and disconnect loudspeaker cathode ground connection.After terminating detection loudspeaker status,
Controller can also be switched to the switch of overvoltage crowbar by third and export conductivity control signal, and front stage circuits are connected and raise
The link of sound device.
To play the role of switching in control disconnection overvoltage crowbar, third switch can be NMOS tube, PMOS tube etc.
The component of on-off action is disconnected with control.
Specifically, the third switch (VT1) includes the 6th NMOS tube (VT1).Wherein, the G of the 6th NMOS tube
Pole connects controller, and the pole D connects the switch of the overvoltage crowbar, the pole S ground connection.
In this present embodiment, the detection circuit includes bleeder circuit and the 4th switch (VT6)；
When detection circuit is used to export the voltage of loudspeaker electrode line road, the bleeder circuit is coupled in supply voltage
Between the anode and cathode of loudspeaker, the bleeder circuit connects supply voltage and loudspeaker when receiving the enable signal
Anode and be grounded the cathode of loudspeaker；
4th switch one end is coupled in loudspeaker electrode line road, and one end couples supply voltage, the 4th switch
The voltage on loudspeaker electrode line road is exported when the bleeder circuit receives the enable signal.
In this present embodiment, the detection circuit includes bleeder circuit and the 4th switch (VT6)；
When the voltage in detection circuit output loudspeaker anode circuit, the detection circuit includes bleeder circuit and the 4th
It switchs (VT6)；
The bleeder circuit is coupled between supply voltage and the anode and cathode of loudspeaker, and the bleeder circuit receives
The cathode of supply voltage and loudspeaker is connected when the enable signal and makes the plus earth of loudspeaker；4th switch one end
It is coupled in loudspeaker anode circuit, one end coupling supply voltage；, the 4th switch receives described in the bleeder circuit
The voltage in loudspeaker anode circuit is exported when enable signal.
In this present embodiment, the 4th switch can be used for the electricity on controller output cathode route or anode circuit
Pressure.For example, the 4th switch can be connected by the ADC pin of MCU, the voltage of SPK electrode line road is read to judge the shape of SPK
State, such as short circuit, breaking (open circuit) etc..
In this present embodiment, the 4th switch includes the 5th NMOS tube (VT6).Specifically, the pole G of the 5th NMOS tube
Supply voltage is connect, the pole S connects controller, and D connects the positive route of loudspeaker.Wherein S can extremely connect the ADC pin of controller.It is described
Detection circuit can also include the resistance (R4, R7) being coupled between the 4th switch and the ADC pin.In this way, the electricity
Resistance constitutes ADC conditioning circuit, and the voltage for acquiring ADC is within ADC sampling range.
In this present embodiment, when the voltage of detection circuit output loudspeaker electrode line road, the bleeder circuit includes
The pull-up resistor being coupled between supply voltage and loudspeaker anode, and the drop-down being coupled between loudspeaker cathode and ground connection
Resistance, the pull-up resistor and the pull down resistor are used to collectively constitute potential-divider network with loudspeaker internal resistance.
In this present embodiment, to play the role of partial pressure, the bleeder circuit can be the tool such as NMOS tube, PMOS tube, resistance
The component for thering is partial pressure to act on.To play the role of output voltage, the 4th switch can have for NMOS tube, PMOS tube etc.
The component of voltage output effect.
Specifically, the bleeder circuit further includes being coupled between supply voltage and loudspeaker anode and being located at institute
Two PMOS tube (VT3, VT5) for stating each side of pull-up resistor, be coupled between loudspeaker cathode and the pull down resistor
Three NMOS tubes (VT4) are also connected with the 4th NMOS tube after described two PMOS tube are in parallel, and the 4th NMOS tube makes for receiving
Simultaneously described two PMOS tube are connected to connect the anode of supply voltage and loudspeaker based on the enable signal in energy signal；Described
Three NMOS tubes (VT4) are for receiving enable signal so that the cathode of loudspeaker is grounded.
Wherein, the third NMOS tube in bleeder circuit and two PMOS tube can act as the effect of anti-high pressure.
NMOS tube and PMOS tube in foregoing circuit can be configured with diode.
In this present embodiment, the detection circuit can also be coupled on the outlet line of supply voltage current-limiting resistance (R2,
R3) to play metering function, and can be with coupling capacitance to play a filtering role.
In the present embodiment, by the overvoltage crowbar in control circuit, it can be protected when loudspeaker is in overvoltage condition
The safety of loudspeaker is protected, further, detects the state of loudspeaker, by the detection circuit in control circuit to find loudspeaking
Device failure.
Application scheme is described in detail by taking overvoltage crowbar and detection circuit as an example separately below.
Embodiment two
The embodiment of the invention also provides a kind of overvoltage crowbar, the overvoltage crowbar includes switch and compares
Device.
Fig. 2 is a kind of block schematic illustration of overvoltage crowbar provided by Embodiment 2 of the present invention, as shown in Fig. 2, described
Overvoltage crowbar includes comparator and switch.
The comparator includes first comparator and the second comparator, and the switch includes first switch and the second switch,
The output end of the first comparator couples first switch, and the output end of second comparator couples second switch；
The input terminal of the first comparator couples the anode of the loudspeaker to acquire cathode voltage and receive the first ginseng
Voltage is examined, when the cathode voltage is more than or equal to first reference voltage, the first comparator is to the first switch
Output disconnects control signal；
The input terminal of second comparator couples the cathode of the loudspeaker to acquire cathode voltage and receive the second ginseng
Voltage is examined, when the cathode voltage is more than or equal to second reference voltage, second comparator is to the second switch
Output disconnects control signal.
Specifically, wherein the first switch and the second switch can be initially set on state.Control letter
Number can be high level or low level, the first switch and the second switch can be set at when receiving low level
It is in the conductive state in off-state, and when receiving high level.When first comparator judges that the cathode voltage is greater than
When first reference voltage, low level is exported to first switch to disconnect first switch, and when the cathode voltage is less than
When first reference voltage, to first switch output high level first switch is connected.Similarly, when the second comparator judges institute
When stating cathode voltage more than or equal to second reference voltage, to second switch output low level to disconnect second switch, and work as
When the cathode voltage is less than second reference voltage, to second switch output high level second switch is connected.Certainly, originally
Field technical staff, which can according to need, is arranged different rule, disconnected with control switch be perhaps connected disconnect realizing or
Connect the communication line of front stage circuits and loudspeaker.
As long as in this way, loudspeaker anode or cathode it is any be in overvoltage condition when, disconnect its corresponding switch, play
Protect the effect of loudspeaker safety.
Meanwhile in over-voltage moment, two comparators can also be respectively to controller report over-voltage identification signal.
In this present embodiment, the output end of the first comparator and second comparator can also respectively with controller
Coupling；
When the cathode voltage is more than or equal to first reference voltage, the first comparator is defeated to the controller
Over-voltage identification signal out；
When the cathode voltage is more than or equal to second reference voltage, second comparator is defeated to the controller
Over-voltage identification signal out.
Wherein, by taking first comparator and first switch as an example, the over-voltage identification signal can be effective for low level.It is described
The output end of first comparator is both couple to first switch, is also coupled to a pin of controller, for example is couple to certain of MCU
On one GPIO pin.When the cathode voltage is more than or equal to first reference voltage, the output end of the first comparator
Low level is exported, which receives low level and be in an off state, which receives low level, and controller is sentenced
Disconnected loudspeaker is in overvoltage condition.
Once the controller can be circuit system in this way, loudspeaker, which is in overvoltage condition, can be reported to controller
Microcontroller (or single-chip microcontroller) or CPU or digital signal processor DSP (Digital Signal
) or Field Programmable Logic Array FPGA (Field-Programmable Gate Array) etc. Processing.Below
It is illustrated so that controller is MCU as an example, but is not limited to MCU.
In this present embodiment, over-voltage identification signal can be reported to controller by AND gate circuit by two comparators, institute
Stating AND gate circuit can be made of two diodes, such as be connected to MCU's after the cathode of two diodes is linked together
On a certain pin, which just constitutes AND gate circuit.The a certain pin of the MCU can be GPIO pin, such as nothing
The GPIO is high level when over-voltage identification signal, when any one comparator output overvoltage identification signal (low level is effective),
GPIO can be pulled low, and MCU is to capture the over-voltage identification signal.
In this present embodiment, to play on-off action, switch can have the member of on-off action for NMOS tube, PMOS tube etc.
Device.Compare to play the role of voltage, comparator there can be electricity for single voltage limit comparator, dual-threshold voltage comparator etc.
Component of the pressure ratio compared with effect.
Fig. 3 is the circuit diagram of overvoltage crowbar provided by Embodiment 2 of the present invention, as shown in figure 3,
In the present embodiment, is formed over-voltage by integrated double N metal-oxide-semiconductor VT9 and two single limit comparator COM_1, COM_2 and protected
Protection circuit, the supply voltage of two single limit comparator COM_1, COM_2 are VCC_PROT, COM_1, COM_2 two single limit ratios
VREF1, VREF2 are respectively corresponded compared with device reference voltage.R10 and R11 constitutes the conditioning network of reference voltage VREF1, makes comparator
COM_1 non-inverting input terminal has suitable reference voltage value, and R8 and R9 constitute the potential-divider network of SPK cathode voltage, make comparator
COM_1 inverting input terminal input voltage is in range ability；Similarly, R14 and R15 constitutes the conditioning network of reference voltage VREF2,
Comparator COM_2 non-inverting input terminal is set to have suitable reference voltage value, R12 and R13 constitute the potential-divider network of SPK cathode voltage,
Make comparator COM_2 inverting input terminal input voltage in range ability.Diode VD1 and VD2 cathode connects after linking together
It is connected on a certain GPIO pin of MCU, the pin configuration is at pull-up input pattern (PU mode) and is low level interrupt trap mould
Formula, then VD1 and VD2 just form AND gate circuit, the GPIO pin is high level when no over-voltage identification signal, any one compares
When device output overvoltage identification signal (low level is effective), GPIO can be pulled low, and MCU is to capture the over-voltage identification signal.It should
Partial capacitor plays a filtering role.
Embodiment three
The embodiment of the invention also provides a kind of detection circuits.Fig. 4 is the detection circuit that the embodiment of the present invention three provides
Block schematic illustration, as shown in figure 4,
The detection circuit is coupled with supply voltage and loudspeaker anode and cathode respectively；
The detection circuit is received enable signal and is connected the anode of supply voltage and loudspeaker based on the enable signal
And it is grounded the cathode of loudspeaker, and the voltage of output loudspeaker electrode line road.
Alternatively, the detection circuit receives enable signal and connects supply voltage and loudspeaker based on the enable signal
Voltage in cathode and the plus earth for making loudspeaker, and output loudspeaker anode circuit.
In this present embodiment, detection circuit can receive enable signal from controller, and just to controller output loudspeaker
Voltage on polar curve road or anode circuit.
Specifically, detection circuit can couple the ADC pin of controller, to controller export loudspeaker anode route or
Voltage in person's anode circuit.In this way, controller can according to need timing or in real time acquisition loudspeaker anode route or
Voltage in anode circuit finds loudspeaker faults to judge the state of loudspeaker in time.The loudspeaker status includes short
Road, open circuit (open circuit) etc..
Before carrying out loudspeaker status detection, controller switchs the switch into the overvoltage crowbar by third
Output disconnects control signal and is reached with disconnecting the communication line between loudspeaker and the front stage circuits of the overvoltage crowbar
The effect of isolation detection circuit and front stage circuits.The front stage circuits of the loudspeaker include power amplification circuit or other are logical
Cross the circuit that overvoltage crowbar is connect with loudspeaker.
Specifically, controller first determines whether loudspeaker is in overvoltage condition, if be in, without in next step
Movement, i.e., the switch that no longer control turns off the overvoltage crowbar also do not enable detection circuit；If be not at, controller
Control disconnects the switch of overvoltage crowbar and enabled detection circuit, to detect the state of loudspeaker.
In this present embodiment, controller switchs the pin of output control signal to third and exports enabled letter to detection circuit
Number pin can be the same pin, be also possible to different pins.
Specifically, when controller switchs the pin of output control signal to third and exports enable signal to detection circuit
Pin when being the same pin, the control signal and the enable signal are the same signals, for example, the signal is high level
When, third switch is configured as receiving in the conductive state when high level and exports low level i.e. to the switch of overvoltage crowbar
Disconnect control signal；Meanwhile detection circuit is configured as reception high level and is in enabled state.Those skilled in the art can root
According to needing to carry out other settings, for example, will control signal and enable signal to be set as low level effective.
Specifically, when controller switchs the pin of output control signal to third and exports enable signal to detection circuit
Pin when not being the same pin, controller switchs output control signal to third respectively, and enabled to detection circuit output
Signal.
To play the role of switching in control disconnection overvoltage crowbar, third switch can be NMOS tube, PMOS tube etc.
The component of on-off action is disconnected with control.
Specifically, the third switch (VT1) includes the 6th NMOS tube (VT1).Wherein, the G of the 6th NMOS tube
Pole connects controller, and the pole D connects the switch of the overvoltage crowbar, the pole S ground connection.
In this present embodiment, the detection circuit includes bleeder circuit and the 4th switch (VT6)；
When detection circuit is used to export the voltage of loudspeaker electrode line road, the bleeder circuit is coupled in supply voltage
Between the anode and cathode of loudspeaker, the bleeder circuit connects supply voltage and loudspeaker when receiving the enable signal
Anode and be grounded the cathode of loudspeaker；
4th switch one end is coupled in loudspeaker electrode line road, and one end couples supply voltage, the 4th switch
The voltage on loudspeaker electrode line road is exported when the bleeder circuit receives the enable signal.
In this present embodiment, the detection circuit includes bleeder circuit and the 4th switch (VT6)；
When the voltage in detection circuit output loudspeaker anode circuit, the detection circuit includes bleeder circuit and the 4th
It switchs (VT6)；
The bleeder circuit is coupled between supply voltage and the anode and cathode of loudspeaker, and the bleeder circuit receives
The cathode of supply voltage and loudspeaker is connected when the enable signal and makes the plus earth of loudspeaker；4th switch one end
It is coupled in loudspeaker anode circuit, one end coupling supply voltage；, the 4th switch receives described in the bleeder circuit
The voltage in loudspeaker anode circuit is exported when enable signal.
In this present embodiment, the 4th switch can be used for the electricity on controller output cathode route or anode circuit
Pressure.For example, the 4th switch can be connected by the ADC pin of MCU, the voltage of SPK electrode line road is read to judge the shape of SPK
State, such as short circuit, breaking (open circuit) etc..
In this present embodiment, the 4th switch includes the 5th NMOS tube (VT6).Specifically, the pole G of the 5th NMOS tube
Supply voltage is connect, the pole S connects controller, and D connects the positive route of loudspeaker.Wherein S can extremely connect the ADC pin of controller.It is described
Detection circuit can also include the resistance (R4, R7) being coupled between the 4th switch and the ADC pin.In this way, the electricity
Resistance constitutes ADC conditioning circuit, and the voltage for acquiring ADC is within ADC sampling range.
In this present embodiment, when the voltage of detection circuit output loudspeaker electrode line road, the bleeder circuit includes
The pull-up resistor (R6) being coupled between supply voltage and loudspeaker anode, and be coupled between loudspeaker cathode and ground connection
Pull down resistor (R5), the pull-up resistor and the pull down resistor are used to collectively constitute potential-divider network with loudspeaker internal resistance.
In this present embodiment, to play the role of partial pressure, the bleeder circuit can be the tool such as NMOS tube, PMOS tube, resistance
The component for thering is partial pressure to act on.To play the role of output voltage, the 4th switch can have for NMOS tube, PMOS tube etc.
The component of voltage output effect.
Specifically, the bleeder circuit further includes being coupled between supply voltage and loudspeaker anode and being located at institute
Two PMOS tube (VT3, VT5) for stating each side of pull-up resistor, be coupled between loudspeaker cathode and the pull down resistor
Three NMOS tubes (VT4) are also connected with the 4th NMOS tube after described two PMOS tube are in parallel, and the 4th NMOS tube makes for receiving
Simultaneously described two PMOS tube are connected to connect the anode of supply voltage and loudspeaker based on the enable signal in energy signal；Described
Three NMOS tubes (VT4) are for receiving enable signal so that the cathode of loudspeaker is grounded.
Wherein, the third NMOS tube in bleeder circuit and two PMOS tube can act as the effect of anti-high pressure.
NMOS tube and PMOS tube in foregoing circuit can be configured with diode.
Fig. 5 is the circuit diagram for the detection circuit that the embodiment of the present invention three provides, as shown in figure 5,
In the present embodiment, SPK_DET_CTL is the shutdown pin that (double NMOS tubes) is switched in MCU control overvoltage crowbar
It is also the enable pin of Speaker state detection circuit.SPK_DET_CTL high level is effective, when SPK_DET_CTL is high,
Metal-oxide-semiconductor VT1 conducting, SPK_OFF_N are low, double N metal-oxide-semiconductors shutdown in overvoltage crowbar.Meanwhile resistance R5, R6 and SPK
The potential-divider network that internal resistance is constituted is connected on route, and the supply voltage of the network is VCC_DEC.It is connected in the potential-divider network
It is to prevent over-voltage from entering electricity from both direction why the circuit of SPK_P, which uses the combination of P metal-oxide-semiconductor VT3 and P metal-oxide-semiconductor VT5,
Road, and connection SPK_N circuit using N metal-oxide-semiconductor VT2 and N metal-oxide-semiconductor VT4 be all using the parasitic body diode of metal-oxide-semiconductor come
Anti- high pressure, the N metal-oxide-semiconductor VT6 being connected with the ADC pin SPK_DEC_ADC of MCU also provide overvoltage protection for MCU, resistance R4 with
R7 constitutes ADC conditioning circuit, makes the voltage of acquisition within ADC sampling range, resistance R2 and R3 play metering function, the part
Capacitor plays a filtering role.
In this way, being separately connected pull-up resistor (R5) and pull down resistor (R6) in SPK positive and negative anodes, constitutes and divide with SPK internal resistance
Network.The voltage of SPK electrode line road is read by the ADC of MCU come state of interpretation SPK, such as open circuit, short-circuit condition etc..
It, can over-voltage, short circuit to SPK in conclusion the scheme in conjunction with described in the embodiment of the present invention two and embodiment three
Or the states such as open circuit (open circuit) are detected, and when SPK is in overvoltage condition, the peace of loudspeaker is protected by open-circuit line
Entirely.
Wherein it is possible to the state of loudspeaker is judged by following principle, such as:
When SPK_P or SPK_N any end or simultaneously to power supply short circuit, overvoltage crowbar works, and is determined as
Pressure condition；
When SPK_P shorted to earth, it is 0 that ADC, which reads potential-divider network front voltage, i.e. N metal-oxide-semiconductor VT6 drain electrode (pole D) electricity
Pressure is 0；Set Rspk first as SPK internal resistance, then when SPK_N shorted to earth, VT6 drain voltage is VCC_DEC*Rspk/ (Rspk+
R6)；When SPK_P and SPK_N are directly linked together then shorted to earth, situation is consistent with SPK_P shorted to earth；
When SPK_P and SPK_N mutually in short-term, i.e. SPK_P and SPK_N is directly linked together, and SPK is short-circuited, at this time VT6
Drain voltage is VCC_DEC*R5/ (R5+R6)；
When SPK open circuit, i.e. SPK_P or SPK_N power supply, shorted to earth and SPK are not connected to normally SPK_P with
On the route of SPK_N, VT6 drain voltage is VCC_DEC at this time.
So pass through the ADC of MCU by reading VT6 drain voltage it may determine that the state of loudspeaker.As SPK_P or
SPK_N any end voltage is higher than reference voltage, so that it may judge that loudspeaker is in overvoltage condition.
In addition, VCC_DEC voltage value should be lower than automobile electricity cell voltage, the input of comparator in embodiment two and three
Reference voltage should also be less than automobile electricity cell voltage, i.e., in 12V automobile power supply system, VCC_DEC/VREF1/VREF2 is answered
Less than 12V, other systems and so on.
Example IV
Overvoltage crowbar provided by the above embodiment and detection circuit can combine or be applied individually to any vehicle-mounted T-
In BOX (Telematics BOX) and other vehicle-mounted products with voice frequency link.Below by taking car audio system as an example into
Row is described in detail.
Fig. 6 is the structural block diagram for the car audio system that the embodiment of the present invention four provides, as shown in Figure 6:
In the present embodiment, which includes audio frequency power amplifier, overvoltage crowbar, detection circuit, microprocessor
(Microcontroller Unit, MCU) and loudspeaker Speaker are constituted.
It is single that the microprocessor (Microcontroller Unit, MCU) is also possible to CPU or DSP or FPGA etc.
Member.
Wherein, audio frequency power amplifier part is responsible for amplifying source of sound.
Wherein, overvoltage crowbar part:
Fig. 7 can be referred to, Fig. 7 is overvoltage crowbar structural schematic diagram involved in the embodiment of the present invention four, such as Fig. 7 institute
Show, which is made of two single limit comparators and two N metal-oxide-semiconductors, two single line comparators acquire respectively Speaker anode,
The voltage of cathode chain road is compared: when real-time voltage is not more than with respective reference voltage by real when collected voltage
When reference voltage, N metal-oxide-semiconductor default is opened；When real-time voltage is greater than reference voltage, comparator control N MOS shutdown, was played
Press the effect of protection.Meanwhile in over-voltage moment, two comparators export two over-voltage identification signals, two over-voltage identification signals
By the AND gate circuit being made of two diodes, it is reported to MCU.Meanwhile two N metal-oxide-semiconductors will be also controlled by a controller,
It carries out turning off two N metal-oxide-semiconductors when Speaker state-detection, plays the role of detection circuit and be isolated with prime link.
Specifically, the output end of the first comparator is coupled to the first NMOS tube, an input terminal is coupled to loudspeaking
The positive cathode voltage to acquire loudspeaker of device, another input terminal receive first reference voltage, when the anode electricity
When pressure is more than or equal to first reference voltage, the first comparator is exported to the first NMOS tube disconnects control signal；
The output end of second comparator is coupled to the second NMOS tube, an input terminal be coupled to the cathode of loudspeaker with
Cathode voltage is acquired, another input terminal receives second reference voltage, when the cathode voltage is more than or equal to described second
When reference voltage, second comparator, which controls to export to the second NMOS tube, disconnects control signal.Wherein, the disconnection control letter
Number can for low level it is effective.
Wherein, the G of first NMOS tube can extremely couple the output end of first comparator, and the pole S is coupled to front stage circuits
And the pole D coupling loudspeaker anode.The G of second NMOS tube can extremely couple the output end of the second comparator, before the coupling of the pole S
Grade circuit and D grades of coupling loudspeaker cathode.
Wherein, Speaker detection circuit part:
The partial circuit is made of multiple metal-oxide-semiconductors.MCU first reads overvoltage crowbar, and whether there is or not over-voltage identification signals: if
Have, there are overvoltage conditions, act without next step；If turning off double N metal-oxide-semiconductors by MCU control without over-voltage identification signal
And enabled detection circuit.In this way, being separately connected pull-up resistor and pull down resistor in SPK positive and negative anodes, partial pressure net is constituted with SPK internal resistance
Network.Reading the voltage on SPK anode to carry out interpretation SPK finally by the ADC of MCU is open circuit, short-circuit condition.
Wherein, the part MCU: the part be mainly responsible for the identification of over-voltage signal, the double N metal-oxide-semiconductor of SPK detection initial shutdown and
Detection circuit is enabled, and reading SPK is open circuit, the function of short-circuit condition.
Wherein, the part Speaker: acoustical signal mainly is converted by the electric signal that prime audio frequency power amplifier is sent, by sound
It plays out.
Embodiment five
The embodiment of the present invention five additionally provides a kind of control method, is applied to controller, which can be circuit system
The microcontroller (or single-chip microcontroller) or CPU or digital signal processor DSP (Digital Signal of system
) or Field Programmable Logic Array FPGA (Field-Programmable Gate Array) etc. Processing.Below
Controller is not limited to MCU by taking MCU as an example
Fig. 8 is the flow diagram for the control method that the embodiment of the present invention five provides, as shown in figure 8, the control method, packet
It includes:
Step 801, when needing to carry out loudspeaker status detection, judge whether loudspeaker is in overvoltage condition；
Step 802, when loudspeaker is not at overvoltage condition, enable signal is sent to detection circuit and passes through the detection
The voltage or the voltage in anode circuit that circuit reads loudspeaker electrode line road, to judge the state of loudspeaker.
It is in this present embodiment, described to judge whether loudspeaker is in overvoltage condition, comprising:
Judge whether to receive over-voltage identification signal, if received, judges that loudspeaker is in overvoltage condition, if do not received
It arrives, then judges that loudspeaker is not at overvoltage condition；
Alternatively, actively reading overvoltage protection signal, if read, judge that loudspeaker is in overvoltage condition, if do not had
It reads, then judges that loudspeaker is not at overvoltage condition.
Wherein it is possible to overvoltage protection signal is passively received, it can also active poll reading overvoltage protection signal.
When loudspeaker is in overvoltage condition, such as when experience impacting with high pressure, it can disconnect in overvoltage crowbar automatically
Switch, to disconnect the connection line of power amplifier and loudspeaker, protection loudspeaker safety makes loudspeaker immediately enter main protection state；
At this point, MCU passively receives over-voltage identification signal or actively reads over-voltage identification signal, judge that loudspeaker is in over-voltage
State then no longer carries out subsequent action, such as enabled detection circuit.
When only loudspeaker is not at overvoltage condition, MCU just enables detection circuit, and the electricity of SPK is read by the ADC of MCU
It is the states such as open circuit or short circuit that pressure, which carrys out interpretation SPK,.
In this present embodiment, before sending enable signal to detection circuit, this method further include:
Control signal is exported to overvoltage crowbar to disconnect the switch in overvoltage crowbar.
In this way, turning off the switch in overvoltage crowbar when carrying out Speaker state-detection, detection circuit is played with before
The effect of grade link isolation.
In this present embodiment, the voltage for reading loudspeaker, the cathode voltage including reading loudspeaker.
In this present embodiment, when reading the voltage of loudspeaker electrode line road by the detection circuit, this method is also
Include:
The state of loudspeaker is judged according to the voltage of the electrode line road, comprising:
The state of loudspeaker is judged according to the voltage of the electrode line road, comprising:
When the voltage of the electrode line road is zero, the state of loudspeaker be the positive route SPK_P of loudspeaker over the ground
Short circuit；
When the voltage of the electrode line road is VCC_DEC*Rspk/ (Rspk+R6), the state of loudspeaker is loudspeaker
Anode circuit SPK_N shorted to earth or SPK_P and SPK_N be directly linked together shorted to earth；
When the voltage of the electrode line road is VCC_DEC*R5/ (R5+R6), the state of loudspeaker be SPK_P with
SPK_N is mutually short；
As the supply voltage VCC_DEC that the voltage of the electrode line road is loudspeaker, the state of loudspeaker is open circuit, i.e.,
SPK_P or SPK_N is not connected to power supply, shorted to earth and SPK normally on the route of SPK_P and SPK_N；
Wherein, Rspk is loudspeaker internal resistance, and R6 is connection loudspeaker anode and constitutes partial pressure net together with loudspeaker internal resistance
The pull-up resistor of network, R5 are the pull down resistor for connecting loudspeaker cathode and constituting potential-divider network together with loudspeaker internal resistance.
Embodiment six
Fig. 9 is a kind of protection of loudspeaker and condition detection method flow diagram that the embodiment of the present invention six provides, and is answered
The car audio system provided for example IV.
As shown in figure 9, this method comprises:
Step 901, when loudspeaker meets with impacting with high pressure, overvoltage crowbar automatically shuts down double N metal-oxide-semiconductors；
It wherein, can be loudspeaker anode route SPK_P or loudspeaker anode circuit when loudspeaker meets with impacting with high pressure
SPK_N any end or simultaneously to power supply short circuit when, at this time determine loudspeaker be in overvoltage condition, overvoltage crowbar acts as
With the double N metal-oxide-semiconductors of shutdown disconnect the route between power amplifier and loudspeaker, loudspeaker enters main protection state, protects
The safety of loudspeaker.
Step 902, whether there is high pressure on overvoltage crowbar detection loudspeaker SPK, if so, then reporting over-voltage to MCU
Identification signal；If not provided, repeating step 902；
Wherein, whether have high pressure, comprising: the comparison of overvoltage crowbar if stating on overvoltage crowbar detection loudspeaker SPK
Device acquires loudspeaker anode or cathode voltage and in real time compared with respective reference voltage.When anode or cathode voltage are greater than
When equal to respective reference voltage, i.e., loudspeaker is in overvoltage condition (being referred to as high pressure conditions), reports over-voltage to know to MCU
Level signal.
Step 903, MCU judges whether there is high pressure on SPK, if so, terminating process；If not thening follow the steps 904；
Wherein, the MCU judges whether there is high pressure on SPK, can be MCU and passively receives overvoltage protection signal, if connect
It receives, judges there is high pressure on SPK, no high pressure on SPK is judged if being not received by；It is also possible to MCU driving wheel to train to read
Overvoltage protection signal is taken, judges there is high pressure on SPK if reading, no high pressure on SPK is judged if not reading.
Step 904, MCU closes double metal-oxide-semiconductors of overvoltage crowbar, and enabled detection circuit；
The wherein double metal-oxide-semiconductors for closing overvoltage crowbar may include drawing high the pin electricity connecting with double metal-oxide-semiconductors
It is flat, low level is exported to double metal-oxide-semiconductors by a NMOS tube, controls double N metal-oxide-semiconductors shutdown in overvoltage crowbar.
The enabled detection circuit, can to detection circuit export high level, by detection circuit connect supply voltage and
Loudspeaker anode, and sample the voltage of the electrode line road of loudspeaker.
Step 905, the ADC pin of MCU reads the sampled voltage of detection circuit；
Wherein the sampled voltage is loudspeaker cathode voltage.
Step 906, the state of SPK is judged according to sampled voltage and reported；
The state that SPK is judged according to sampled voltage may include:
When sampled voltage is 0, then SPK_P shorted to earth or SPK_P and SPK_N are directly linked together over the ground
Short circuit,
When sampled voltage is VCC_DEC*Rspk/ (Rspk+R6), SPK_N shorted to earth；
When sampled voltage is VCC_DEC*R5/ (R5+R6), SPK_P is shorted with each other with SPK_N；That is SPK_P and SPK_N
It is directly linked together, SPK is short-circuited；
When sampled voltage is VCC_DEC, SPK open circuit, i.e. SPK_P or SPK_N do not have power supply, shorted to earth and SPK
Have and is normally connected on the route of SPK_P and SPK_N；
Wherein, VCC_DEC is power speakers voltage, and Rspk is SPK internal resistance, and R5 is pull down resistor, and R6 is pull-up resistor,
Resistance R5, R6 and SPK internal resistance constitutes potential-divider network and is connected on route.
Step 907, detecting state is exited.
Wherein, exiting detecting state to may include: may include dragging down the pin level connecting with double metal-oxide-semiconductors, pass through one
A NMOS tube exports high level to double metal-oxide-semiconductors, double N metal-oxide-semiconductors conducting in overvoltage crowbar.It can also include: to drag down and examine
The pin level of slowdown monitoring circuit exports low level to detection circuit, positive by detection circuit disconnection supply voltage and loudspeaker
Connection.
The embodiment of the invention also provides a kind of control device, described device includes: memory, processor and is stored in institute
The program that can be run on memory and on the processor is stated, described program realizes above-mentioned control when being executed by the processor
Method.
The embodiment of the invention also provides a kind of electronic equipment, including above-mentioned control circuit, further include controller, the control
Device processed is configured as executing above-mentioned control method.
The embodiment of the invention also provides a kind of computer readable storage medium for being stored with computer executable instructions, institutes
It states computer executable instructions to be performed, realizes above-mentioned control method.
Although disclosed herein embodiment it is as above, the content only for ease of understanding the present invention and use
Embodiment is not intended to limit the invention.Technical staff in any fields of the present invention is taken off not departing from the present invention
Under the premise of the spirit and scope of dew, any modification and variation, but the present invention can be carried out in the form and details of implementation
Scope of patent protection, still should be subject to the scope of the claims as defined in the appended claims.
Claims (19)
1. a kind of control circuit, which is characterized in that the control circuit includes: overvoltage crowbar, the overvoltage crowbar packet
Comparator and switch are included, the switch is coupled between loudspeaker and the front stage circuits of the overvoltage crowbar；
The comparator is coupled to the voltage of acquisition loudspeaker compared with received reference voltage, and works as the electricity of the loudspeaker
When pressure is more than or equal to the reference voltage, control switch disconnects the communication line of the front stage circuits and the loudspeaker.
2. control circuit according to claim 1, which is characterized in that
The comparator includes first comparator and the second comparator, and the switch includes first switch and the second switch, described
The output end of first comparator couples first switch, and the output end of second comparator couples second switch；
The input terminal of the first comparator couples the anode of the loudspeaker to acquire cathode voltage and receive first with reference to electricity
Pressure, when the cathode voltage is more than or equal to first reference voltage, the first comparator is exported to the first switch
Disconnect control signal；
The input terminal of second comparator couples the cathode of the loudspeaker to acquire cathode voltage and receive second with reference to electricity
Pressure, when the cathode voltage is more than or equal to second reference voltage, second comparator is exported to the second switch
Disconnect control signal.
3. control circuit according to claim 2, which is characterized in that
The output end of the first comparator and second comparator is also used to couple with controller；
When the cathode voltage is more than or equal to first reference voltage, the first comparator was exported to the controller
Press identification signal；
When the cathode voltage is more than or equal to second reference voltage, second comparator was exported to the controller
Press identification signal.
4. control circuit according to claim 2, which is characterized in that
The control signal that the first switch and the second switch and controller are coupled, and sent based on controller, disconnects institute
State the communication line of front stage circuits and the loudspeaker.
5. control circuit according to claim 2, which is characterized in that the first switch includes the first NMOS tube, described
Second switch includes the second NMOS tube, and the first comparator and second comparator are single voltage limit comparator；
Wherein, the output end of the first comparator is coupled to the first NMOS tube, and inverting input terminal is coupled to the anode of loudspeaker
To acquire the cathode voltage of loudspeaker, non-inverting input terminal receives first reference voltage, when the cathode voltage is more than or equal to
When first reference voltage, the first comparator is exported to the first NMOS tube disconnects control signal；
The output end of second comparator is coupled to the second NMOS tube, and inverting input terminal is coupled to the cathode of loudspeaker to acquire
Cathode voltage, non-inverting input terminal receive second reference voltage, when the cathode voltage is more than or equal to described second with reference to electricity
When pressure, second comparator, which controls to export to the second NMOS tube, disconnects control signal.
6. control circuit according to claim 1, which is characterized in that the control circuit further include: detection circuit；
Anode and cathode of the detection circuit respectively with supply voltage and loudspeaker couple；
The detection circuit receives enable signal and connects the anode of supply voltage and loudspeaker based on the enable signal and make
The cathode of loudspeaker is grounded, and the voltage of output loudspeaker electrode line road；Alternatively, receiving enable signal and being made based on described
Energy signal connects the cathode of supply voltage and loudspeaker and makes the plus earth of loudspeaker, and in output loudspeaker anode circuit
Voltage.
7. control circuit according to claim 6, which is characterized in that the control circuit further include: third switchs (VT1),
The third switch couples the switch of the overvoltage crowbar；
The third switch disconnects control signal for receiving control signal and exporting to the switch.
8. control circuit according to claim 7, which is characterized in that
The third switch (VT1) includes the 6th NMOS tube (VT1).
9. control circuit according to claim 6, which is characterized in that
When the voltage of detection circuit output loudspeaker electrode line road, the detection circuit includes bleeder circuit and the 4th switch
(VT6)；
The bleeder circuit is coupled between supply voltage and the anode and cathode of loudspeaker, and the bleeder circuit receives described
The anode of supply voltage and loudspeaker is connected when enable signal and is grounded the cathode of loudspeaker；4th switch one end coupling
On loudspeaker electrode line road, one end coupling supply voltage；4th switch receives described enabled in the bleeder circuit
The voltage of loudspeaker electrode line road is exported when signal；
Alternatively, the detection circuit includes bleeder circuit and the when the voltage in detection circuit output loudspeaker anode circuit
Four switches (VT6)；
The bleeder circuit is coupled between supply voltage and the anode and cathode of loudspeaker, and the bleeder circuit receives described
The cathode of supply voltage and loudspeaker is connected when enable signal and makes the plus earth of loudspeaker；4th switch one end coupling
In loudspeaker anode circuit, one end coupling supply voltage；4th switch receives described enabled in the bleeder circuit
The voltage in loudspeaker anode circuit is exported when signal.
10. control circuit according to claim 9, which is characterized in that
When the voltage of detection circuit output loudspeaker electrode line road, the bleeder circuit includes being coupled in supply voltage and raising
Pull-up resistor between sound device anode, and the pull down resistor being coupled between loudspeaker cathode and ground connection, the pull-up resistor
It is used to collectively constitute potential-divider network with loudspeaker internal resistance with the pull down resistor.
11. control circuit according to claim 10, which is characterized in that
The bleeder circuit further includes being coupled between supply voltage and loudspeaker anode and to be located at the pull-up resistor each
Two PMOS tube (VT3, VT5) of side, the third NMOS tube being coupled between loudspeaker cathode and the pull down resistor
(VT4), it also connects with the 4th NMOS tube after described two PMOS tube are in parallel, the 4th NMOS tube is for receiving enable signal simultaneously
Described two PMOS tube are connected to connect the anode of supply voltage and loudspeaker based on the enable signal；The third NMOS tube
(VT4) for receiving enable signal so that the cathode of loudspeaker is grounded.
12. control circuit according to claim 9, which is characterized in that
4th switch includes the 5th NMOS tube (VT6).
13. a kind of control method, comprising:
When needing to carry out loudspeaker status detection, judge whether loudspeaker is in overvoltage condition；
When loudspeaker is not at overvoltage condition, enable signal is sent to detection circuit and loudspeaking is read by the detection circuit
The voltage or the voltage in anode circuit of device electrode line road, to judge the state of loudspeaker.
14. according to the method for claim 13, which is characterized in that before sending enable signal to detection circuit, the party
Method further include:
Control signal is exported to overvoltage crowbar to disconnect the switch in overvoltage crowbar.
15. according to the method for claim 13, which is characterized in that
It is described to judge whether loudspeaker is in overvoltage condition, comprising:
Judge whether to receive over-voltage identification signal, if received, judges that loudspeaker is in overvoltage condition, if do not received,
Then judge that loudspeaker is not at overvoltage condition；
Alternatively, actively reading overvoltage protection signal, if read, judge that loudspeaker is in overvoltage condition, if do not read
It gets, then judges that loudspeaker is not at overvoltage condition.
16. the method according to claim 11, which is characterized in that read loudspeaker electrode line when passing through the detection circuit
When the voltage of road, this method further include:
The state of loudspeaker is judged according to the voltage of the electrode line road, comprising:
When the voltage of the electrode line road is zero, the state of loudspeaker is the positive route SPK_P shorted to earth of loudspeaker；
When the voltage of the electrode line road is VCC_DEC*Rspk/ (Rspk+R6), the state of loudspeaker is the negative of loudspeaker
Polar curve road SPK_N shorted to earth or SPK_P and SPK_N are directly linked together shorted to earth；
When the voltage of the electrode line road is VCC_DEC*R5/ (R5+R6), the state of loudspeaker is that SPK_P and SPK_N is mutual
It is short；
As the supply voltage VCC_DEC that the voltage of the electrode line road is loudspeaker, the state of loudspeaker is open circuit, i.e. SPK_
P or SPK_N is not connected to power supply, shorted to earth and loudspeaker SPK normally on the route of SPK_P and SPK_N；
Wherein, Rspk is loudspeaker internal resistance, and R6 is connection loudspeaker anode and constitutes potential-divider network together with loudspeaker internal resistance
Pull-up resistor, R5 are the pull down resistor for connecting loudspeaker cathode and constituting potential-divider network together with loudspeaker internal resistance.
17. a kind of control device, which is characterized in that described device includes: memory, processor and is stored on the memory
And the program that can be run on the processor, it is realized when described program is executed by the processor as in claim 13 to 16
Described in any item methods.
18. a kind of electronic equipment, which is characterized in that further include control including control circuit as claimed in claim 1
Device processed, the controller are configured as executing the method as described in any one of claim 13 to 16.
19. a kind of computer readable storage medium for being stored with computer executable instructions, the computer executable instructions quilt
When execution, the method as described in claim 13 to 16 is any is realized.
Priority Applications (2)
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| CN201810290854.6A CN110350473B (en) | 2018-04-03 | 2018-04-03 | Control circuit, method and device |
| PCT/CN2019/077982 WO2019192298A1 (en) | 2018-04-03 | 2019-03-13 | Control circuit, control method and apparatus, electronic device, and storage medium |
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| CN201810290854.6A CN110350473B (en) | 2018-04-03 | 2018-04-03 | Control circuit, method and device |
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| CN110350473B CN110350473B (en) | 2022-08-12 |
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| CN112535517B (en) * | 2020-11-12 | 2023-09-08 | 嘉善飞阔医疗科技有限公司 | Two-wire ultrasonic scalpel system with multiple control inputs |
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Also Published As
| Publication number | Publication date |
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| WO2019192298A1 (en) | 2019-10-10 |
| CN110350473B (en) | 2022-08-12 |
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