CN109407579B - Independent sound wave algorithm control circuit - Google Patents
Independent sound wave algorithm control circuit Download PDFInfo
- Publication number
- CN109407579B CN109407579B CN201811202446.7A CN201811202446A CN109407579B CN 109407579 B CN109407579 B CN 109407579B CN 201811202446 A CN201811202446 A CN 201811202446A CN 109407579 B CN109407579 B CN 109407579B
- Authority
- CN
- China
- Prior art keywords
- sound wave
- tube
- driving circuit
- wave driving
- voltage
- 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
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
- G05B19/0423—Input/output
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/20—Pc systems
- G05B2219/24—Pc safety
- G05B2219/24215—Scada supervisory control and data acquisition
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Amplifiers (AREA)
Abstract
The invention discloses an independent sound wave algorithm control circuit, which comprises: the sound wave driving power supply is used for converting power supply voltage into high voltage required by the sound wave driving circuit module under the control of a boosting control signal VOICE _ PWR _ CTRL; the sound wave driving circuit module is used for driving and amplifying the eight paths of PWM signals output by the microprocessor module so as to be suitable for driving the high-voltage buzzer module to send sound wave warning with deterrence; the microprocessor module is used for receiving an instruction of an upper computer, controlling the sound wave driving power supply to generate the high voltage and outputting 8 paths of PWM signals to the sound wave driving circuit module; the high-voltage buzzer module is used for converting the four paths of high-voltage variable-frequency PWM signals output by the sound wave driving circuit module into sound wave warning with deterrence force.
Description
Technical Field
The invention relates to the technical field of safety protection, in particular to an independent sound wave algorithm control circuit.
Background
Currently, with the development of science and technology, various industries, such as finance, traffic, public security and the like, have urgent needs for prevention and control of important areas, and various safety precautionary measures are brought forward.
Among many safety precautionary measures, sound wave alarm is one of the most commonly used means, and the sound wave alarm means that when an illegal criminal event occurs, sound wave on site is used for triggering a button to start sound wave deterrence so as to force the criminal behavior to be stopped.
Therefore, it is necessary to provide a technical solution to solve the above problems.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide an independent sound wave algorithm control circuit, which is used for driving output by frequency conversion PWM (pulse width modulation) based on CPU (central processing unit) control to drive a high-voltage sound wave driving circuit consisting of MOS (metal oxide semiconductor) tubes to generate a specific waveform, and the driving waveform is loaded on a specially-made high-voltage buzzer, so that a sound wave warning effect with deterrent force is generated, the deterrent range is wide, and the circuit is harmless to the hearing of an intruder to be repelled or a person in a defense area or a body.
To achieve the above and other objects, the present invention provides an independent acoustic wave algorithm control circuit, comprising:
the sound wave driving power supply is used for converting power supply voltage into high voltage required by the sound wave driving circuit module under the control of a boosting control signal VOICE _ PWR _ CTRL;
the sound wave driving circuit module is used for driving and amplifying the eight paths of PWM signals output by the microprocessor module so as to be suitable for driving the high-voltage buzzer module to send sound wave warning with deterrence;
the microprocessor module is used for receiving an instruction of an upper computer, controlling the sound wave driving power supply to generate the high voltage and outputting 8 paths of PWM signals to the sound wave driving circuit module;
and the high-voltage buzzer module is used for converting the four paths of high-voltage variable-frequency PWM signals output by the sound wave driving circuit module into sound wave warning with deterrence.
Preferably, the sound wave driving power supply converts a 12V power supply voltage into a 36V-48V high voltage required by the sound wave driving circuit module under the control of the boost control signal VOICE _ PWR _ CTRL.
Preferably, the sound wave driving circuit module comprises a first sound wave driving circuit, a second sound wave driving circuit, a third sound wave driving circuit and a fourth sound wave driving circuit, and each sound wave driving circuit is used for driving and amplifying two paths of PWM signals so as to be suitable for driving the high-voltage buzzer module to send out sound wave warning with deterrence force.
Preferably, the eight PWM signals outputted from the microprocessor module are divided into four groups, each two PWM signals are divided into one group, that is, PWM0 and PWM1 are connected to the first sound wave driving circuit as the first group, PWM2 and PWM3 are connected to the second sound wave driving circuit as the second group, PWM4 and PWM5 are connected to the third sound wave driving circuit as the third group, and PWM6 and PWM7 are divided into the fourth group, and connected to the fourth sound wave driving circuit.
Preferably, the frequencies and duty cycles of the drive waveforms of the four sets of PWM outputs are all different and varied.
Preferably, the high-voltage buzzer module adopts four groups of high-voltage buzzers so as to convert four paths of high-voltage variable-frequency PWM signals output by the sound wave driving circuit module into sound wave warning with deterrence force.
Preferably, the sound wave driving power supply comprises driving tubes Q9 and Q10 and a switching tube Q8, as well as respective bias and load resistors, an input current limiting resistor R80, an output current limiting resistor R82, filter capacitors E10 and C52, and an external boost module socket CON 13.
Preferably, each acoustic wave driving circuit comprises two NPN buffer tubes and peripheral circuits thereof, a plurality of preamplifiers and power driving MOS tubes.
Compared with the prior art, the independent sound wave algorithm control circuit is based on the variable frequency PWM driving output controlled by the CPU, the high-voltage sound wave driving circuit consisting of the MOS tube is driven to generate a specific waveform, and the driving waveform is loaded on the specially-made high-voltage buzzer, so that the sound wave warning effect with deterrence force is generated, the deterrence range is wide, and the hearing or the body of an intruder to be expelled or a person in a defense area is not damaged.
Drawings
FIG. 1 is a circuit diagram of an independent acoustic algorithm control circuit according to the present invention;
fig. 2 is a detailed structure diagram of the acoustic wave driving power supply 10 according to the embodiment of the present invention;
fig. 3 is a schematic structural diagram of a driving circuit for driving a high-voltage buzzer in an embodiment of the present invention.
Detailed Description
Other advantages and capabilities of the present invention will be readily apparent to those skilled in the art from the present disclosure by describing the embodiments of the present invention with specific embodiments thereof in conjunction with the accompanying drawings. The invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention.
Fig. 1 is a circuit structure diagram of an independent sound wave algorithm control circuit according to the present invention. As shown in fig. 1, the independent acoustic wave algorithm control circuit of the present invention includes: the sound wave driving circuit comprises a sound wave driving power supply 10, a sound wave driving circuit module 20, a Microprocessor (MCU) module 30 and a high-voltage buzzer module 40.
The sound wave driving power supply 10 consists of driving tubes Q9 and Q10, a switching tube Q8, bias and load resistors, an input current limiting resistor R80, an output current limiting resistor R82, a filter capacitor E10 and C52, and an external boosting module socket CON13, and is used for converting a 12V power supply voltage into a 36V high voltage required by the sound wave driving circuit module 20 under the control of a boosting control signal VOICE _ PWR _ CTRL;
the sound wave driving circuit module 20 is composed of a first sound wave driving circuit 201, a second sound wave driving circuit 202, a third sound wave driving circuit 203 and a fourth sound wave driving circuit 204, and is used for driving and amplifying eight paths of PWM signals PWM0-PWM7 output by the Microprocessor (MCU) module 30 so as to be suitable for driving the high-voltage buzzer module 40 to send out sound wave warnings with deterrence force, the structures of the first to fourth sound wave driving circuits are completely the same except for different inputs, and are specifically described by the first sound wave driving circuit 201; the first sound wave driving circuit 201 consists of NPN buffer tubes Q11-Q12 and peripheral circuits thereof, preamplification tubes U10, U11, U14, U15 and power driving MOS tubes U12-U13, PWM0 is connected to the base electrode of the NPN buffer tube Q12 through a resistor R88, the collector electrode of the NPN buffer tube Q12 is connected to the input end (2 feet and 5 feet) of the preamplification tube U10, PWM1 is connected to the input end (2 feet and 5 feet) of the preamplification tube U14 through a resistor R93 and a resistor R95 together through PWM0R, the preamplification tube U10 is cascaded with the preamplification tube U14, the connection point is a reference voltage REF _ V, the output end of the pre-amplification tube U10 is connected to the first input end (4 pin) of the power driving MOS tube U12, the output end of the pre-amplification tube U14 is connected to the second input end (2 pin) of the power driving MOS tube U12, and the output ends (5, 6, 7 and 8 pins) of the power driving MOS tube U12 are first output positive ends DRV +; the PWM1 is commonly connected to the base of an NPN buffer tube Q11 through resistors R89 and PWM0R through resistor R90, the collector of the NPN buffer tube Q11 is connected to the input terminals (pin 2 and pin 5) of the pre-amplification tube U11, the PWM0 is connected to the input terminals (pin 2 and pin 5) of the pre-amplification tube U15 through resistor R94, the pre-amplification tube U11 is cascaded with the pre-amplification tube U15, the connection point thereof is a reference voltage REF _ V, the output terminal of the pre-amplification tube U11 is connected to the first input terminal (pin 4) of the power driving MOS tube U13, the output terminal of the pre-amplification tube U15 is connected to the second input terminal (pin 2) of the power driving MOS tube U13, and the output terminals ( pin 5, 6, 7, 8) of the power driving MOS tube U13 are the first output negative terminal DRV-; the resistors R86 and R87 are load resistors, the resistors R91 and R92 are emitter resistors and are used for stabilizing bias voltage and increasing input impedance, the resistor C53 is used for stabilizing reference voltage REF _ V, and the PTC2 is a positive temperature current-limiting protection resistor.
The Microprocessor (MCU) module 30 is composed of any microprocessor with pulse width modulation output (32-bit CPU with M0 core: LPC1115 is used in the present embodiment) and its peripheral circuits, and is used to receive upper computer instructions and control the sound wave driving power supply 10 to generate 36V high voltage and output 8 channels of PWM to the sound wave driving circuit module 20, specifically, eight channels of PWM signals output by the Microprocessor (MCU) module 30 are divided into four groups, each two signals are a group, that is, PWM0 and PWM1 are a first group, connected to the first sound wave driving circuit 201, PWM2 and PWM3 are a second group, connected to the second sound wave driving circuit 202, PWM4 and PWM5 are a third group, connected to the third sound wave driving circuit 203, PWM6 and PWM7 are a fourth group, connected to the fourth sound wave driving circuit 204, and the frequencies and duty ratios of the driving waveforms output by the four groups of PWM are all different and are varied.
The high-voltage buzzer module 40 is four groups of high-voltage buzzers, and is configured to convert the four paths of high-voltage variable-frequency PWM signals output by the sound wave driving circuit module 20 into sound wave warning with deterrence.
Specifically, fig. 2 is a detailed structural diagram of the acoustic wave driving power supply 10 according to the embodiment of the present invention. In order to obtain a specific sound wave effect with deterrence, the invention adopts a special high-voltage buzzer, and the driving working voltage of the high-voltage buzzer is up to 36-48V. The working voltage adopted by the invention is 12V, so that the working voltage of 12V needs to be boosted to 36-48V. The figure shows a power module (CON 13) converting 12V to 36V 3A. When sound waves are not output at ordinary times, the CPU controls the input 12V of the boosting module to be switched off through a control circuit composed of devices such as Q8, Q9 and Q10, the boosting module does not work, and therefore system power consumption is reduced, the service life of the power supply module is prolonged, and the overall reliability of the system is improved. When the sound wave is output, the CPU controls the input 12V of the boosting module to be opened, and the boosting module works. And after the boost module is started for 1 second, loading the output of the first drive waveform PWM0 and PWM1, then loading the output of the last three drive waveforms every 1 second, and finally outputting the four drive waveforms.
Fig. 3 is a schematic structural diagram of a driving circuit for driving a high-voltage buzzer in an embodiment of the present invention. PWM0, PWM0R and PWM1 are PWM driving signals output by the CPU through program control, after the PWM driving signals are pre-amplified by U10, U11, U14 and U15, MOS power amplification output consisting of U12 and U13 is driven, and signals DRV1+ and DRV 1-output through MOS power amplification are loaded on a high-voltage buzzer to generate high-sound waves. The frequency and the duty ratio of the four-path output driving waveforms are different and are variable, and the four-path output driving waveforms are superposed to finally obtain the sound wave warning effect with deterrence.
In conclusion, the independent sound wave algorithm control circuit drives the high-voltage sound wave driving circuit composed of the MOS tubes to generate a specific waveform based on the variable-frequency PWM driving output controlled by the CPU, and the driving waveform is loaded on the specially-made high-voltage buzzer, so that the sound wave warning effect with deterrence force is generated, the deterrence range is wide, and the hearing or the body of an intruder or a person in a defense area is not damaged.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Therefore, the scope of the invention should be determined from the following claims.
Claims (8)
1. An independent acoustic algorithm control circuit comprising:
the sound wave driving power supply is used for converting power supply voltage into high voltage required by the sound wave driving circuit module under the control of a boosting control signal VOICE _ PWR _ CTRL;
the sound wave driving circuit module is used for driving and amplifying the eight paths of PWM signals output by the microprocessor module so as to be suitable for driving the high-voltage buzzer module to send sound wave warning with deterrence;
the microprocessor module is used for receiving an instruction of an upper computer, controlling the sound wave driving power supply to generate the high voltage and outputting 8 paths of PWM signals to the sound wave driving circuit module;
the high-voltage buzzer module is used for converting the four paths of high-voltage variable-frequency PWM signals output by the sound wave driving circuit module into sound wave warning with deterrence;
the first acoustic wave driving circuit 201 is composed of NPN buffer tubes Q11-Q12 and peripheral circuits thereof, preamplification tubes U10, U11, U14, U15 and power driving MOS tubes U12-U13, the PWM0 is connected to the base of the NPN buffer tube Q12 through a resistor R88, the collector of the NPN buffer tube Q12 is connected to the input end of the preamplification tube U10, the PWM1 is commonly connected to the input end of the preamplification tube U14 through resistors R93 and PWM0R, the preamplification tube U10 is cascaded with the preamplification tube U14, the connection point is a reference voltage REF _ V, the output end of the preamplification tube U10 is connected to the first input end of the power driving MOS tube U12, the output end of the preamplification tube U14 is connected to the second input end of the power driving tube U12, and the output end of the power driving MOS tube U12 is a first output positive output end drmos V +; the PWM1 is commonly connected to the base of an NPN buffer tube Q11 through resistors R89 and PWM0R through a resistor R90, the collector of the NPN buffer tube Q11 is connected to the input end of a pre-amplification tube U11, the PWM0 is connected to the input end of a pre-amplification tube U15 through a resistor R94, the pre-amplification tube U11 is in cascade connection with a pre-amplification tube U15, the connection point of the pre-amplification tube U11 is a reference voltage REF _ V, the output end of the pre-amplification tube U11 is connected to the first input end of a power driving MOS tube U13, the output end of the pre-amplification tube U15 is connected to the second input end of a power driving MOS tube U13, and the output end of the power driving MOS tube U13 is a; the resistors R86 and R87 are load resistors, the resistors R91 and R92 are emitter resistors and are used for stabilizing bias voltage and increasing input impedance, the resistor C53 is used for stabilizing reference voltage REF _ V, and the PTC2 is a positive temperature current-limiting protection resistor.
2. An isolated acoustic algorithm control circuit as claimed in claim 1, wherein: the sound wave driving power supply converts a 12V power supply voltage into a 36V-48V high voltage required by the sound wave driving circuit module under the control of the boost control signal VOICE _ PWR _ CTRL.
3. An isolated acoustic algorithm control circuit as claimed in claim 1, wherein: the sound wave driving circuit module comprises a first sound wave driving circuit, a second sound wave driving circuit, a third sound wave driving circuit and a fourth sound wave driving circuit, and each sound wave driving circuit is used for driving and amplifying two paths of PWM signals so as to be suitable for driving the high-voltage buzzer module to send sound wave warning with deterrence force.
4. An isolated acoustic algorithm control circuit as claimed in claim 3, wherein: eight paths of PWM signals output by the microprocessor module are divided into four groups, wherein every two signals are a group, namely PWM0 and PWM1 are a first group and are connected to the first sound wave driving circuit, PWM2 and PWM3 are a second group and are connected to the second sound wave driving circuit, PWM4 and PWM5 are a third group and are connected to the third sound wave driving circuit, and PWM6 and PWM7 are fourth groups and are connected to the fourth sound wave driving circuit.
5. An isolated acoustic algorithm control circuit as claimed in claim 4, wherein: the frequencies and duty ratios of the driving waveforms of the four groups of PWM outputs are different and are variable.
6. An isolated acoustic algorithm control circuit as claimed in claim 1, wherein: the high-voltage buzzer module adopts four groups of high-voltage buzzers so as to convert four paths of high-voltage variable-frequency PWM signals output by the sound wave driving circuit module into sound wave warning with deterrence.
7. An isolated acoustic algorithm control circuit as claimed in claim 1, wherein: the sound wave driving power supply comprises driving tubes Q9 and Q10, a switching tube Q8, bias resistors, load resistors, an input current limiting resistor R80, an output current limiting resistor R82, filter capacitors E10 and C52 and an external boosting module socket CON 13.
8. An isolated acoustic algorithm control circuit as claimed in claim 1, wherein: each acoustic wave driving circuit comprises two NPN buffer tubes and peripheral circuits thereof, a plurality of preamplification tubes and a power driving MOS tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811202446.7A CN109407579B (en) | 2018-10-16 | 2018-10-16 | Independent sound wave algorithm control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811202446.7A CN109407579B (en) | 2018-10-16 | 2018-10-16 | Independent sound wave algorithm control circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109407579A CN109407579A (en) | 2019-03-01 |
| CN109407579B true CN109407579B (en) | 2021-06-01 |
Family
ID=65467217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811202446.7A Active CN109407579B (en) | 2018-10-16 | 2018-10-16 | Independent sound wave algorithm control circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109407579B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2133029Y (en) * | 1992-05-16 | 1993-05-12 | 林文骅 | Contactless electric loudspeaker for automobile |
| JP2007033939A (en) * | 2005-07-27 | 2007-02-08 | Denso Corp | Piezo-electric buzzer driving circuit |
| CN101174410A (en) * | 2006-09-25 | 2008-05-07 | 株式会社派特莱 | Alarm whistle device for emergency vehicle and alarm whistle system for emergency vehicle |
| CN201262827Y (en) * | 2008-09-19 | 2009-06-24 | 周锷 | Piezoelectric sound generator |
| CN101594565A (en) * | 2009-06-30 | 2009-12-02 | 北京东微世纪科技有限公司 | The integrated drive electronics of multifunctional electrical sound generation device |
| CN201533397U (en) * | 2009-11-06 | 2010-07-21 | 杭州蓝海特种车辆有限公司 | Digital audio-frequency power-amplification circuit |
| CN203014946U (en) * | 2012-12-20 | 2013-06-19 | 龙尚科技（上海）有限公司 | Apparatus capable of driving fierce dog away by ultrasonic wave on mobile phone |
| CN103222189A (en) * | 2011-02-28 | 2013-07-24 | 唯听助听器公司 | Hearing aid with an H-bridge output stage and a method of driving an output stage |
| CN205487320U (en) * | 2016-01-05 | 2016-08-17 | 常州东村电子有限公司 | Piezoelectric type buzzer BTL drive circuit |
| JP2018107752A (en) * | 2016-12-28 | 2018-07-05 | 株式会社Ｃｒｉ・ミドルウェア | Audio reproducing device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8643436B2 (en) * | 2011-11-22 | 2014-02-04 | Analog Devices, Inc. | Multi-level boosted Class D amplifier |
-
2018
- 2018-10-16 CN CN201811202446.7A patent/CN109407579B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2133029Y (en) * | 1992-05-16 | 1993-05-12 | 林文骅 | Contactless electric loudspeaker for automobile |
| JP2007033939A (en) * | 2005-07-27 | 2007-02-08 | Denso Corp | Piezo-electric buzzer driving circuit |
| CN101174410A (en) * | 2006-09-25 | 2008-05-07 | 株式会社派特莱 | Alarm whistle device for emergency vehicle and alarm whistle system for emergency vehicle |
| CN201262827Y (en) * | 2008-09-19 | 2009-06-24 | 周锷 | Piezoelectric sound generator |
| CN101594565A (en) * | 2009-06-30 | 2009-12-02 | 北京东微世纪科技有限公司 | The integrated drive electronics of multifunctional electrical sound generation device |
| CN201533397U (en) * | 2009-11-06 | 2010-07-21 | 杭州蓝海特种车辆有限公司 | Digital audio-frequency power-amplification circuit |
| CN103222189A (en) * | 2011-02-28 | 2013-07-24 | 唯听助听器公司 | Hearing aid with an H-bridge output stage and a method of driving an output stage |
| CN203014946U (en) * | 2012-12-20 | 2013-06-19 | 龙尚科技（上海）有限公司 | Apparatus capable of driving fierce dog away by ultrasonic wave on mobile phone |
| CN205487320U (en) * | 2016-01-05 | 2016-08-17 | 常州东村电子有限公司 | Piezoelectric type buzzer BTL drive circuit |
| JP2018107752A (en) * | 2016-12-28 | 2018-07-05 | 株式会社Ｃｒｉ・ミドルウェア | Audio reproducing device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109407579A (en) | 2019-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8259470B2 (en) | Control circuit, control method, and power supply device | |
| CN104065266B (en) | Control circuit for voltage converter | |
| CN103905006A (en) | D-type power amplifier chip with duty-ratio limit function and device of D-type power amplifier chip | |
| US8044715B2 (en) | Method and system for increasing sampling frequency for switching amplifiers | |
| WO2008019122A2 (en) | Startup and shutdown click noise elimination for class d amplifier | |
| US6807071B1 (en) | Transformer isolated driver | |
| CN101160716B (en) | Device comprising a switching amplifier and a load | |
| CN109407579B (en) | Independent sound wave algorithm control circuit | |
| CN106655784B (en) | full-bridge LLC converter short circuit current control circuit and control method | |
| JP2003504001A (en) | Boost bridge amplifier | |
| US6778012B2 (en) | Polyphase impedance transformation amplifier | |
| WO2022222711A1 (en) | Electric motor controller safety state switching circuit and apparatus, and control method | |
| CN214045983U (en) | Power amplifier device and amplitude limiting circuit thereof | |
| CN104181461A (en) | Fault detection assembly and method for microwave switch | |
| US8552376B2 (en) | Pyroelectric motion detection circuit | |
| WO2024041267A1 (en) | Audio power amplifier circuit, and duty ratio modulation circuit and noise suppression circuit thereof | |
| CN106059513A (en) | DC detection protection circuit and D type amplifier applying same | |
| CN213755052U (en) | Lamp control module and electric vehicle instrument | |
| JP2007089371A (en) | Back converter | |
| JP2004096826A (en) | Switching power supply | |
| CN112671375A (en) | Power amplifier device and amplitude limiting circuit thereof | |
| CN210110334U (en) | Buzzer driving circuit | |
| CN105513584A (en) | Buzz output method and device | |
| JP3151130B2 (en) | Step-up chopper circuit of ± 2 DC power supply of half-bridge type inverter sharing battery power supply | |
| CN216531127U (en) | Servo motor protection 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 |