CN220107952U - Audio amplifying circuit and repeater for access control system - Google Patents
Audio amplifying circuit and repeater for access control system Download PDFInfo
- Publication number
- CN220107952U CN220107952U CN202321708857.XU CN202321708857U CN220107952U CN 220107952 U CN220107952 U CN 220107952U CN 202321708857 U CN202321708857 U CN 202321708857U CN 220107952 U CN220107952 U CN 220107952U
- Authority
- CN
- China
- Prior art keywords
- double
- operational amplifier
- inverting input
- resistor
- audio
- 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
- 230000009977 dual effect Effects 0.000 claims description 56
- 238000002955 isolation Methods 0.000 claims description 31
- 239000003990 capacitor Substances 0.000 claims description 27
- 238000004804 winding Methods 0.000 claims description 24
- 230000003321 amplification Effects 0.000 claims description 19
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 19
- 230000003287 optical effect Effects 0.000 claims 1
- 230000005236 sound signal Effects 0.000 description 46
- 238000004891 communication Methods 0.000 description 7
- 230000003068 static effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Amplifiers (AREA)
Abstract
The utility model provides an audio amplifying circuit and a repeater for an access control system, wherein the circuit comprises: the first inverting input end of the first double-operation amplifier is connected with a first connecting port of the door machine, the first output end of the first double-operation amplifier is connected with a first input pin of the audio processing chip, the first output pin of the audio processing chip is connected with a third inverting input end of the second double-operation amplifier, and the third output end of the second double-operation amplifier is connected with a second connecting port of the indoor machine; the second connection port of the indoor unit is also connected with a fourth inverting input end of the second double-operational amplifier, a fourth output end of the second double-operational amplifier is connected with a second input pin of the audio processing chip, a second output pin of the audio processing chip is connected with a second inverting input end of the first double-operational amplifier, and a second output end of the first double-operational amplifier is connected with a first connection port of the entrance machine. The utility model saves components and space.
Description
Technical Field
The utility model relates to the field of access control systems, in particular to an audio amplifying circuit and a repeater for an access control system.
Background
The entrance guard system between the building includes gate machine and indoor set, and when the distance between gate machine and the indoor set was too big, the gate machine was carried out the communication with indoor set, and the audio signal that transmits can decay to lead to communication quality to reduce, influence user's experience sense.
The existing circuit structure for amplifying audio signals comprises a voltage amplifying circuit and a power amplifying circuit, wherein the voltage amplifying circuit uses an integrated double operational amplifier, the voltage amplifying circuit performs voltage amplification on received audio signals, the audio signals subjected to voltage amplification are input into the power amplifying circuit to perform power amplification, and the audio signals subjected to power amplification push a loudspeaker to make sound through a coupling capacitor. The circuit structure for amplifying the audio signal can only realize one-way input and one-way output, and when the circuit structure is applied to an access control system, two circuits for amplifying the audio signal are required to be used for realizing two-way communication, and the occupied space is large.
Disclosure of Invention
A first object of the present utility model is to provide an audio amplifying circuit for an access control system that can communicate bi-directionally.
The second object of the present utility model is to provide a repeater applying the above-mentioned audio amplifying circuit for an access control system.
In order to achieve the first objective, the audio amplifying circuit for an access control system provided by the utility model comprises a first double operational amplifier and a second double operational amplifier, wherein a first inverting input end of the first double operational amplifier is connected with a first connecting port of a door phone, a first output end of the first double operational amplifier is connected with a first input pin of an audio processing chip, a first output pin of the audio processing chip is connected with a third inverting input end of the second double operational amplifier, and a third output end of the second double operational amplifier is connected with a second connecting port of an indoor unit; the second connection port of the indoor unit is also connected with a fourth inverting input end of the second double-operational amplifier, a fourth output end of the second double-operational amplifier is connected with a second input pin of the audio processing chip, a second output pin of the audio processing chip is connected with a second inverting input end of the first double-operational amplifier, and a second output end of the first double-operational amplifier is connected with a first connection port of the entrance machine.
According to the scheme, when the audio signal is input into the first connection port of the entrance machine, the audio signal can be restored and amplified by the audio amplifying circuit for the entrance system and then output to the indoor machine; when the second connection port of the indoor unit is provided with the audio signal input, the audio signal can be restored and amplified by the audio amplifying circuit of the access control system and then output to the entrance machine; when the first connection port of the door phone is provided with the audio signal input, the first double-operation amplifier of the circuit amplifies the attenuated audio signal, after the intercom balance judgment is realized through the audio processing chip, the second double-operation amplifier restores the audio signal, so that the audio signal realizes the optimal restoration degree when the door phone and the indoor unit are in communication, and the communication between the door phone and the indoor unit is smoother. The audio amplifying circuit for the access control system can restore and amplify the audio signals input by the door phone or the indoor unit, and when the audio signals are input by the door phone or the indoor unit, the components such as the first double operational amplifier, the audio processing chip, the second double operational amplifier and the like are used, so that the components are fully utilized, the circuit volume is saved, and the space occupation area is reduced.
In a further scheme, a first RC parallel circuit is arranged between a first inverting input end and a first output end of the first double operational amplifier, and the first RC parallel circuit comprises a first resistor and a first capacitor which are connected in parallel; a second RC parallel circuit is arranged between the second inverting input end and the second output end of the first double operational amplifier, and comprises a second resistor and a second capacitor which are connected in parallel; a third RC parallel circuit is arranged between a third inverting input end and a third output end of the second double-operation amplifier, and comprises a third resistor and a third capacitor which are connected in parallel; a fourth RC parallel circuit is arranged between the fourth inverting input end and the fourth output end of the second double-operational amplifier, and comprises a fourth resistor and a fourth capacitor which are connected in parallel.
It follows that the amplification factor and time constant are determined by the arrangement of the RC parallel circuit.
In a further scheme, a first non-inverting input end of the first double-operational amplifier is connected with a first end of a fifth resistor, and a second end of the fifth resistor is connected with a voltage input end; the first non-inverting input end of the first double operational amplifier is also connected with the first end of a sixth resistor, and the second end of the sixth resistor is connected with the first grounding end; the first end of the sixth resistor is also connected with the first end of the fifth capacitor, and the second end of the fifth capacitor is connected with the first grounding end; the second non-inverting input end of the first double operational amplifier is connected with the first end of the fifth resistor.
It can be seen that the fifth resistor and the sixth resistor are bias resistors for setting the static operating point of the first dual operational amplifier.
In a further scheme, a third non-inverting input end of the second double-operational amplifier is connected with a first end of a seventh resistor, and a second end of the seventh resistor is connected with a voltage input end; the third non-inverting input end of the second double-operational amplifier is also connected with the first end of an eighth resistor, and the second end of the eighth resistor is connected with the second grounding end; the first end of the eighth resistor is also connected with the first end of the sixth capacitor, and the second end of the sixth capacitor is connected with the second grounding end; the fourth non-inverting input terminal of the second double operational amplifier is connected with the first terminal of the seventh resistor.
It can be seen that the seventh resistor and the eighth resistor are bias resistors for setting the static operating point of the second dual operational amplifier.
In a further scheme, the first connecting port of the gate machine is also connected with a collector of a first triode, a base electrode of the first triode is connected with a collector end of the optocoupler, and an emitter electrode of the first triode is connected with a first grounding end; the anode end of the optocoupler is connected with the voltage input end, and the cathode end of the optocoupler receives a control signal of the pin of the first singlechip; the emitter terminal of the optocoupler is connected with the first grounding terminal.
Therefore, the first singlechip pin outputs a control signal to control the audio amplifying circuit for the access control system.
In a further scheme, the second connecting port of the indoor unit is also connected with the collector electrode of the second triode, the base electrode of the second triode is connected with the collector electrode of the third triode, and the emitter electrode of the second triode is connected with the second grounding end; the base electrode of the third triode receives the control signal of the second singlechip pin, and the emitter electrode of the third triode is connected with the second grounding end.
Therefore, the second singlechip pin outputs a control signal to control the audio amplifying circuit for the access control system
In a further scheme, a first isolation transformer is further arranged between the first output end of the first double-operation amplifier and the first input pin of the audio processing chip, the first end of the first winding of the first isolation transformer is connected with the first output end of the first double-operation amplifier, and the second end of the first winding of the first isolation transformer is connected with the first grounding end; the first end of the second winding of the first isolation transformer is connected with a first input pin of the audio processing chip, and the second end of the second winding of the first isolation transformer is connected with a second grounding end.
It follows that the first isolation transformer electrically isolates the circuitry of the first dual op-amp from the circuitry of the second dual op-amp such that the circuitry of the first dual op-amp and the circuitry of the second dual op-amp do not interfere with each other.
In a further scheme, a second isolation transformer is further arranged between the second output pin of the audio processing chip and the second inverting input end of the first double operational amplifier, the first end of the third winding of the second isolation transformer is connected with the second output pin of the audio processing chip, and the second end of the third winding of the second isolation transformer is connected with the second grounding end; the first end of the fourth winding of the second isolation transformer is connected with the second inverting input end of the first double operational amplifier, and the second end of the fourth winding of the second isolation transformer is connected with the first grounding end.
It follows that the second isolation transformer electrically isolates the circuitry of the first dual op-amp from the circuitry of the second dual op-amp such that the circuitry of the first dual op-amp and the circuitry of the second dual op-amp do not interfere with each other.
In order to achieve the second objective, the repeater provided by the present utility model includes a single chip microcomputer, and is characterized in that: the repeater also comprises the audio amplifying circuit for the access control system, and the singlechip outputs a control signal to control the repeater.
Drawings
Fig. 1 is a circuit diagram of an embodiment of an audio amplification circuit for an access control system of the present utility model.
Fig. 2 is a circuit diagram of a first dual op amp of an embodiment of an audio amplification circuit for a door access system of the present utility model.
Fig. 3 is a circuit diagram of a second dual op amp of an embodiment of the audio amplification circuit for a door access system of the present utility model.
The utility model is further described below with reference to the drawings and examples.
Detailed Description
Repeater embodiment:
the entrance guard system comprises a gate machine, an indoor unit and a repeater, wherein the repeater is used for connecting the gate machine with the indoor unit, and when the gate machine is communicated with the indoor unit, the repeater can restore and amplify audio signals transmitted by the gate machine or the indoor unit. The repeater comprises a singlechip and an audio amplification circuit, wherein the singlechip sends a control signal to the repeater to control the repeater, and the audio amplification circuit restores and amplifies an audio signal.
An audio amplification circuit embodiment for an access control system:
referring to fig. 1 and 2, the audio amplifying circuit for the access control system includes a first dual operational amplifier IC1 and a second dual operational amplifier IC2, where the first dual operational amplifier IC1 and the second dual operational amplifier IC2 are LM358, and the LM358 chip includes 2 operational amplifiers. The first connecting port of the gate machine is connected with the first inverting input end of the first operational amplifier in the first dual operational amplifier IC1, and the first inverting input end of the first dual operational amplifier IC1 is the 6 th pin of the first dual operational amplifier IC 1. The first non-inverting input end of the first dual operational amplifier IC1 is the 5 th pin of the first dual operational amplifier IC1, the first non-inverting input end of the first dual operational amplifier IC1 is connected with the first end of the fifth resistor R58, and the second end of the fifth resistor R58 is connected with the voltage input end. The first non-inverting input terminal of the first dual operational amplifier is also connected to the first terminal of the sixth resistor R57, and the second terminal of the sixth resistor R57 is connected to the first ground terminal. The first end of the sixth resistor R57 is also connected with the first end of the fifth capacitor C14, and the second end of the fifth capacitor C14 is connected with the first grounding end; the fifth resistor R58 and the sixth resistor R57 are bias resistors for setting a static operating point of the first dual operational amplifier. The first output end of the first dual operational amplifier IC1 is the 7 th pin of the first dual operational amplifier IC1, a first RC parallel circuit is arranged between the first output end and the first inverting input end, and the first RC parallel circuit comprises a first resistor R71 and a first capacitor C30. The first end of the first RC parallel circuit is connected with the first inverting input end of the first double operational amplifier IC1, and the second end of the first RC parallel circuit is connected with the first output end of the first double operational amplifier IC 1. The amplification factor and time constant of the first operational amplifier are determined by the first RC parallel circuit.
The first output end of the first dual operational amplifier IC1 is connected with the first end of the first winding of the first isolation transformer T3, and the second end of the first winding of the first isolation transformer T3 is connected with the first grounding end. A first end of a second winding of the first isolation transformer T3 is connected to the first input pin au_in2 of the audio processing chip IC3, and a second end of the second winding of the first isolation transformer is connected to a second ground end. The first isolation transformer T3 electrically isolates the circuitry of the first dual operational amplifier IC1 from the circuitry of the second dual operational amplifier IC2 such that the circuitry of the first dual operational amplifier IC1 and the circuitry of the second dual operational amplifier IC2 do not interfere with each other.
Referring to fig. 3, the audio processing chip IC3 is MC34118, and the audio processing chip IC3 determines whether the audio signal is input from the door phone or the indoor unit, if the audio signal is input from the door phone, the audio signal input from the indoor unit is cut off, and if the audio signal is input from the indoor unit, the audio signal input from the door phone is cut off. The audio processing chip IC3 can realize the judgment of intercom balance, so that the sound signal of the door phone and the audio signal of the indoor unit are not interfered with each other.
After receiving the audio signal from the first input pin au_in2, the audio processing chip IC3 performs an intercom balance determination, and then outputs the audio signal from the first output pin au_out2, where the first output pin au_out2 of the audio processing chip IC3 is connected to the third inverting input terminal of the second dual operational amplifier, and the third inverting input terminal of the second dual operational amplifier IC2 is the 2 nd pin of the second dual operational amplifier IC 2.
The third output terminal of the second dual operational amplifier IC2 is pin 1 of the second dual operational amplifier IC 2. A third RC parallel circuit is arranged between a third inverting input end and a third output end of the second double-operational amplifier IC2, and comprises a third resistor R38 and a third capacitor C29; the first end of the third RC parallel circuit is connected with the third inverting input end of the second double-operational amplifier IC2, and the second end of the third RC parallel circuit is connected with the third output end of the second double-operational amplifier IC 2.
The third non-inverting input end of the second double-operational amplifier IC2 is the 3 rd pin of the second double-operational amplifier IC2, the third non-inverting input end of the second double-operational amplifier IC2 is connected with the first end of a seventh resistor R59, and the second end of the seventh resistor R59 is connected with the voltage input end; the third non-inverting input end of the second double-operational amplifier is also connected with the first end of an eighth resistor R60, and the second end of the eighth resistor R60 is connected with the second grounding end; the first end of the eighth resistor R60 is further connected to the first end of the sixth capacitor C15, and the second end of the sixth capacitor C15 is connected to the second ground. The seventh resistor R59 and the eighth resistor R60 are bias resistors for setting a static operating point of the second dual operational amplifier.
The third output end of the second double-operational amplifier is connected with the second connecting port of the indoor unit and outputs the restored audio signal. The second connection port of the indoor unit is also connected with a fourth inverting input end of the second dual-operational amplifier IC2, and the fourth inverting input end of the second dual-operational amplifier IC2 is a 6 th pin of the second dual-operational amplifier IC 2. The fourth non-inverting input end of the second dual operational amplifier IC2 is the 5 th pin of the second dual operational amplifier IC2, and the fourth non-inverting input end of the second dual operational amplifier IC2 is connected with the third non-inverting input end of the second dual operational amplifier IC 2.
The fourth output end of the second dual operational amplifier IC2 is the 7 th pin of the second dual operational amplifier IC2, and a fourth RC parallel circuit is arranged between the fourth inverting input end and the fourth output end of the second dual operational amplifier IC2 and comprises a fourth resistor R72 and a fourth capacitor C31. The first end of the fourth RC parallel circuit is connected with the fourth inverting input end of the second dual-operational amplifier IC2, and the second end of the fourth RC parallel circuit is connected with the fourth output end of the second dual-operational amplifier IC 2. The fourth resistor R72 and the fourth capacitor C31 determine the amplification factor and the time constant.
The fourth output end of the second double operational amplifier IC2 is connected with a second input pin AU_In1 of the audio processing chip IC3, after the audio processing chip IC3 carries out intercom balance judgment on the audio signal, the audio signal is output to a second output pin AU_In2, the second output pin AU_In2 of the audio processing chip IC3 is connected with the first end of the third winding of the second isolation transformer T2, and the second end of the third winding of the second isolation transformer T2 is connected with the second grounding end. The first end of the fourth winding of the second isolation transformer T2 is connected with the second inverting input end of the first dual operational amplifier IC1, and the second end of the fourth winding of the second isolation transformer T2 is connected with the first grounding end.
The second inverting input end of the first dual operational amplifier IC1 is the 2 nd pin of the first dual operational amplifier IC1, the second non-inverting input end of the first dual operational amplifier IC1 is the 3 rd pin of the first dual operational amplifier IC1, and the second non-inverting input end of the first dual operational amplifier IC1 is connected with the first end of the fifth resistor R58. The second output end of the first dual operational amplifier IC1 is the 1 st pin of the first dual operational amplifier IC1, a second RC parallel circuit is arranged between the second inverting input end and the second output end of the first dual operational amplifier IC1, and the second RC parallel circuit comprises a second resistor R37 and a second capacitor C28; the first end of the second RC parallel circuit is connected with the second inverting input end of the first dual operational amplifier IC1, and the second end of the second RC parallel circuit is connected with the second output end of the first dual operational amplifier IC 1. The second resistor R37 and the second capacitor C28 determine the time constant and the amplification factor. The second output end of the first double operational amplifier IC1 is connected with the first connection port of the entrance machine.
The first connecting port of the gate machine is also connected with a collector of a first triode Q1, a base electrode of the first triode Q1 is connected with a collector end of an optocoupler PC2, and an emitter electrode of the first triode Q1 is connected with a first grounding end; the anode end of the optocoupler PC2 is connected with the voltage input end, and the cathode end of the optocoupler PC2 receives a control signal of the first singlechip pin M_AU_OFF 1; the base electrode of the first triode Q1 is also connected with a first connection port of the gate machine. When the singlechip outputs a control signal to the first singlechip pin M_AU_OFF1, the triode in the optocoupler PC2 is conducted, the base electrode of the first triode Q1 is low level, the first triode Q1 is cut OFF, and at the moment, an audio signal is input from the first inverting input end of the first double-operational amplifier IC 1. When the singlechip does not output a control signal to the pin M_AU_OFF1 of the first singlechip, the optocoupler PC2 is not conducted, when the base electrode of the first triode Q1 receives a high-level signal, the first triode Q1 is conducted, and an audio signal cannot be transmitted to the first inverting input end of the first double operational amplifier IC 1.
The second connecting port of the indoor unit is also connected with the collector electrode of a second triode Q2, the base electrode of the second triode Q2 is connected with the collector electrode of a third triode Q3, and the emitter electrode of the second triode Q2 is connected with a second grounding end; the base electrode of the third triode Q3 receives a control signal of the second singlechip pin M_AU_OFF2, the emitter electrode of the third triode Q3 is connected with a second grounding end, and the base electrode of the second triode Q2 is also connected with a second connecting port of the indoor unit. When the singlechip outputs a control signal to the second singlechip pin M_AU_OFF2, at the moment, the third triode Q3 is conducted, the second triode Q2 is low level, the second triode Q2 is cut OFF, and at the moment, an audio signal is input from the third inverting input end of the second double-operational amplifier IC 2. When the singlechip does not output a control signal to the pin M_AU_OFF2 of the second singlechip, the third triode Q3 is not conducted, when the base electrode of the second triode Q2 receives a high-level signal, the second triode is conducted, and an audio signal cannot be transmitted to the third inverting input end of the second double-operational amplifier IC 2.
When the first connection port of the entrance machine is provided with an audio signal input, an audio amplifying circuit for the entrance guard system can restore and amplify the audio signal and then output the audio signal to the indoor machine; when the second connection port of the indoor unit is provided with the audio signal input, the audio signal can be restored and amplified by the audio amplifying circuit of the access control system and then output to the entrance machine; when the first connection port of the door phone is provided with the audio signal input, the first double-operation amplifier of the circuit amplifies the attenuated audio signal, after the intercom balance judgment is realized through the audio processing chip, the second double-operation amplifier restores the audio signal, so that the audio signal realizes the optimal restoration degree when the door phone and the indoor unit are in communication, and the communication between the door phone and the indoor unit is smoother. The audio amplifying circuit for the access control system can restore and amplify the audio signals input by the door phone or the indoor unit, and when the audio signals are input by the door phone or the indoor unit, the components such as the first double operational amplifier, the audio processing chip, the second double operational amplifier and the like are used, so that the components are fully utilized, the circuit volume is saved, and the space occupation area is reduced.
The foregoing is merely a preferred embodiment of the present utility model, but the inventive design concept is not limited thereto, and many other equivalent embodiments can be included without departing from the scope of the utility model, as will be apparent to those skilled in the art.
Claims (9)
1. An audio amplification circuit for an access control system, comprising:
the first inverting input end of the first double-operation amplifier is connected with a first connecting port of the door phone, the first output end of the first double-operation amplifier is connected with a first input pin of the audio processing chip, the first output pin of the audio processing chip is connected with a third inverting input end of the second double-operation amplifier, and the third output end of the second double-operation amplifier is connected with a second connecting port of the indoor phone;
the second connection port of the indoor unit is also connected with the fourth inverting input end of the second double-operation amplifier, the fourth output end of the second double-operation amplifier is connected with the second input pin of the audio processing chip, the second output pin of the audio processing chip is connected with the second inverting input end of the first double-operation amplifier, and the second output end of the first double-operation amplifier is connected with the first connection port of the entrance machine.
2. The audio amplification circuit for an access control system of claim 1, wherein:
a first RC parallel circuit is arranged between a first inverting input end and the first output end of the first double-operational amplifier, and the first RC parallel circuit comprises a first resistor and a first capacitor which are connected in parallel;
a second RC parallel circuit is arranged between the second inverting input end and the second output end of the first double-operational amplifier, and the second RC parallel circuit comprises a second resistor and a second capacitor which are connected in parallel;
a third RC parallel circuit is arranged between a third inverting input end and the third output end of the second double-operation amplifier, and comprises a third resistor and a third capacitor which are connected in parallel;
a fourth RC parallel circuit is disposed between the fourth inverting input terminal and the fourth output terminal of the second dual operational amplifier, and the fourth RC parallel circuit includes a fourth resistor and a fourth capacitor connected in parallel.
3. The audio amplification circuit for an access control system of claim 2, wherein:
the first non-inverting input end of the first dual-operational amplifier is connected with the first end of the fifth resistor, and the second end of the fifth resistor is connected with the voltage input end;
the first non-inverting input end of the first dual-operational amplifier is also connected with the first end of a sixth resistor, and the second end of the sixth resistor is connected with the first grounding end;
the first end of the sixth resistor is also connected with the first end of a fifth capacitor, and the second end of the fifth capacitor is connected with the first grounding end;
the second non-inverting input end of the first double operational amplifier is connected with the first end of the fifth resistor.
4. An audio amplifying circuit for an access control system according to claim 3, wherein:
the third non-inverting input end of the second double-operational amplifier is connected with the first end of a seventh resistor, and the second end of the seventh resistor is connected with the voltage input end;
the third non-inverting input end of the second double-operational amplifier is also connected with the first end of an eighth resistor, and the second end of the eighth resistor is connected with the second grounding end;
the first end of the eighth resistor is also connected with the first end of the sixth capacitor, and the second end of the sixth capacitor is connected with the second grounding end;
the fourth non-inverting input terminal of the second double operational amplifier is connected with the first terminal of the seventh resistor.
5. The audio amplifier circuit for an access control system of claim 4, wherein:
the first connecting port of the gate machine is also connected with a collector of a first triode, a base electrode of the first triode is connected with a collector end of the optical coupler, an emitter electrode of the first triode is connected with the first grounding end, and the base electrode of the first triode is also connected with the first connecting port;
the anode end of the optocoupler is connected with the voltage input end, and the cathode end of the optocoupler receives a control signal of a first singlechip pin;
the emitter end of the optocoupler is connected with the first grounding end.
6. The audio amplifier circuit for an access control system of claim 5, wherein:
the second connecting port of the indoor unit is also connected with a collector electrode of a second triode, a base electrode of the second triode is connected with a collector electrode of a third triode, and an emitter electrode of the second triode is connected with the second grounding end;
the base electrode of the third triode receives a control signal of the second singlechip pin, and the emitter electrode of the third triode is connected with the second grounding end.
7. The audio amplification circuit for an access control system of claim 6, wherein:
a first isolation transformer is further arranged between the first output end of the first double-operation amplifier and the first input pin of the audio processing chip, a first end of a first winding of the first isolation transformer is connected with the first output end of the first double-operation amplifier, and a second end of the first winding of the first isolation transformer is connected with the first grounding end;
the first end of the second winding of the first isolation transformer is connected with the first input pin of the audio processing chip, and the second end of the second winding of the first isolation transformer is connected with the second grounding end.
8. The audio amplification circuit for an access control system of claim 7, wherein:
a second isolation transformer is further arranged between the second output pin of the audio processing chip and the second inverting input end of the first double operational amplifier, the first end of the third winding of the second isolation transformer is connected with the second output pin of the audio processing chip, and the second end of the third winding of the second isolation transformer is connected with the second grounding end;
and a first end of a fourth winding of the second isolation transformer is connected with a second inverting input end of the first double operational amplifier, and a second end of the fourth winding of the second isolation transformer is connected with the first grounding end.
9. The repeater, the repeater includes singlechip, its characterized in that: the repeater further comprises an audio amplifying circuit for an access control system according to any one of claims 1 to 8, and the single-chip microcomputer outputs a control signal to control the repeater.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321708857.XU CN220107952U (en) | 2023-06-30 | 2023-06-30 | Audio amplifying circuit and repeater for access control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321708857.XU CN220107952U (en) | 2023-06-30 | 2023-06-30 | Audio amplifying circuit and repeater for access control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220107952U true CN220107952U (en) | 2023-11-28 |
Family
ID=88881612
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202321708857.XU Active CN220107952U (en) | 2023-06-30 | 2023-06-30 | Audio amplifying circuit and repeater for access control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220107952U (en) |
-
2023
- 2023-06-30 CN CN202321708857.XU patent/CN220107952U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN220107952U (en) | Audio amplifying circuit and repeater for access control system | |
| CN104218903A (en) | WiFi (wireless fidelity) signal amplifier based on automatic gain control technology | |
| CN105072241A (en) | Anti-sidetone circuit of intercom system isolation transformer | |
| CN204795237U (en) | Intercom system isolation transformer antisidetone circuit | |
| CN214544805U (en) | High-power wireless network card | |
| CN106911313A (en) | A kind of low-noise amplifier | |
| CN204790442U (en) | A digital ALC circuit for link is amplified to repeater | |
| CN216313181U (en) | Audio recording circuit and wireless fixed telephone | |
| CN112653792A (en) | Voice switching control system, method and medium | |
| CN110380790B (en) | Receiving device and receiving method of ultra-low optical power receiver | |
| CN2319965Y (en) | Dynamic noise reducing language processor | |
| CN210201972U (en) | Low-power consumption intelligent visual doorbell | |
| CN212305505U (en) | Video signal amplifying circuit for talkback video doorbell | |
| CN204948029U (en) | A kind of pre-amplifier device of digital intecommunication system | |
| CN108650586B (en) | High-sensitivity microphone sound code telephone circuit | |
| KR20100079900A (en) | Power line communication circuit | |
| CN202551140U (en) | Host talking and receiving circuit for voice-frequency circuit of entrance guard talkback | |
| CN210042177U (en) | Voice broadcasting device | |
| CN115664361A (en) | Automatic gain control circuit | |
| CN212137921U (en) | Control device and loudspeaker equipment | |
| CN206759453U (en) | Mobile phone signal amplifier control circuit | |
| CN215268252U (en) | Signal amplification circuit of wireless communication equipment | |
| CN208849761U (en) | A kind of long standby mobile phone used suitable for field | |
| CN210670531U (en) | Signal receiving and decoding circuit | |
| CN208046575U (en) | A kind of power amplifying system of intercom |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |