CN218734328U

CN218734328U - Control circuit for digital control of analog broadcasting

Info

Publication number: CN218734328U
Application number: CN202222428259.9U
Authority: CN
Inventors: 刘春玖; 刘缤璐
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-09-14
Filing date: 2022-09-14
Publication date: 2023-03-24
Anticipated expiration: 2032-09-14

Abstract

The utility model relates to a control circuit for carrying out digital control on analog broadcasting, which comprises a No. 1 main control board, a No. 2 branch control board and a No. 3 drive board; wherein, the No. 1 main control board is provided with a conversion chip IC3, a singlechip IC7, an IC4 and the like; n single-chip microcomputers IC1-x are arranged on the No. 2 sub-control board; 15 photoelectric couplers U-x and 15 class relays J-x are mounted on the No. 3 driving plate; the power supply for controlling the power amplifiers of the areas such as a front-end, a corridor, a class, a playground and the like is switched on/off by controlling the output pin of the singlechip IC7 to be at low and high levels, so that music bells are played in the areas; the high and low levels output by the 4 pins of the IC4 are controlled to realize the broadcasting and answering of the talk back in a certain class and realize the bidirectional single-function talkback function; and the output pins of the single-chip microcomputer IC1-x on the number 2 sub-control board are controlled to be low and high levels, and the class broadcasting terminal is switched on/off, so that the functions of single class broadcasting, random combined broadcasting and the like are realized.

Description

Control circuit for digital control of analog broadcasting

Technical Field

The utility model belongs to the technical field of the campus broadcasting, concretely relates to a control circuit for being used for carrying out digital control to analog broadcast.

Background

Since birth, the analog broadcasting system has been developed from the electronic tube to the transistor, has been liked by people with stable product performance, simple operation flow, convenient construction and loud sound, is widely applied to public places such as colleges and universities, primary and secondary schools, enterprises, prisons and the like, and plays an important role in school teaching management in particular. With the development of science and technology and economy, digital broadcasting is also on the market, and is accepted by the society in more digital management modes and better sound effect, and gradually enters the campus.

Although the analog broadcast has the advantages of over-hard product quality, lower construction cost, simple and easy-to-learn operation flow, energy and electricity conservation, safety and reliability and lower construction and maintenance technical level, the analog broadcast has the advantages of single management function, manual operation and control, and can not realize the functions of independent broadcast of any class, random combined broadcast of all classes, annual group broadcast and the like; although digital broadcasting has more broadcasting functions, and audio materials and unattended management modes are enriched, the digital broadcasting has the defects of poor product stability, high construction cost and strong construction and maintenance speciality, and has the risks of energy consumption, potential safety hazards, long-term standby power supply for 24 hours for all equipment, fire, electric shock and the like.

If the digital control function is additionally arranged on the analog broadcast, the analog broadcast can realize the digital broadcast function, the construction cost can be reduced, the potential safety hazard can be eliminated, the operation flow can be simplified, the defects of multiple equipment faults and the like can be overcome, and an unattended management mode can be realized.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a control circuit for carrying out digital control to analog broadcast, this control circuit is low, the high level through the output pin of control singlechip IC7, and the switch-on/switch-off is used for controlling the power of regional power amplifiers such as leading, corridor, class and playground, realizes playing the music bell in the region; the high and low levels output by the 4 pins of the IC4 are controlled to realize the broadcasting and answering of the talk back in a certain class and realize the bidirectional single-function talkback function; and the output pins of the single-chip microcomputer IC1-x on the number 2 sub-control board are controlled to be low and high levels, and the class broadcasting terminal is switched on/off, so that the functions of single class broadcasting, random combined broadcasting and the like are realized.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a control circuit for carrying out digital control on analog broadcasting comprises a No. 1 main control board, a No. 2 sub-control board electrically connected with the No. 1 main control board, and a No. 3 drive board electrically connected with the No. 2 sub-control board; wherein, level conversion chip IC3, singlechip IC7, singlechip IC4, echo amplification circuit are installed on the No. 1 main control board; the No. 2 sub-control board is provided with N (1-10) single-chip microcomputers IC1-x; 15 photoelectric couplers U-x and 15 class relays J-x are mounted on the No. 3 driving plate;

pins

7 and 8 of the level conversion chip IC3 are connected with a computer, the rs232 signal level of a serial port of the computer is converted into a TTL signal used by the singlechip, and the TTL signal is connected with

pins

10 and 11 of the singlechip IC4, the singlechip IC7 and N singlechips IC1-x through

pins

9 and 10 of the IC 3;

a pin 24 of the singlechip IC7 is electrically connected with a music bell control diode D21, and the music bell control diode D21 is electrically connected with a photoelectric coupler U5; the pin 25 is electrically connected with a music bell control diode D20, and the music bell control diode D20 is electrically connected with a photoelectric coupler U4; the pin 26 is electrically connected with a music bell control diode D19, and the music bell control diode D19 is electrically connected with a photoelectric coupler U3; the pin 27 is electrically connected with a music bell control diode D18, and the music bell control diode D18 is electrically connected with a photoelectric coupler U2; pin 28 is electrically connected with music bell control diode D17, and music bell control diode D17 is electrically connected with photoelectric coupler U1;

the photoelectric coupler U5, the photoelectric coupler U4, the photoelectric coupler U3, the photoelectric coupler U2 and the photoelectric coupler U1 are electrically connected with a port P4, and the port P4 is electrically connected with a relay J5 for controlling a power supply of a power amplifier in the corridor 2, a relay J4 for controlling a power supply of a front power amplifier, a relay J3 for controlling a power supply of a playground power amplifier, a relay J2 for controlling a power supply of a classroom power amplifier and a relay J1 for controlling the power supply of the power amplifier in the corridor 1; the corridor 2 power amplifier, the playground power amplifier, the classroom power amplifier and the corridor 1 power amplifier are constant-voltage power amplifiers and are all connected with the audio output by the front power amplifier;

a 24 pin of the singlechip IC4 is electrically connected with a broadcast control diode D16, and the broadcast control diode D16 is electrically connected with a photoelectric coupler U5; the pin 25 is electrically connected with a broadcast control diode D15, and the broadcast control diode D15 is electrically connected with a photoelectric coupler U4; pin 26 is electrically connected with a broadcast control diode D14, and the broadcast control diode D14 is electrically connected with a photoelectric coupler U3; the 27 pin is electrically connected with a broadcast control diode D13, and the broadcast control diode D13 is electrically connected with a photoelectric coupler U2; pin 28 is electrically connected with a broadcast control diode D12, and the broadcast control diode D12 is electrically connected with a photoelectric coupler U1;

pins

3, 4 and 5 of the singlechip IC4 are respectively and electrically connected with a photoelectric coupler U6, a photoelectric coupler U7 and a photoelectric coupler U8, the photoelectric coupler U6 is electrically connected with a relay JR5V, the photoelectric coupler U7 is electrically connected with a relay JR0 and a relay JR1, and the photoelectric coupler U8 is electrically connected with a relay JR 1-1;

the relay JR5V is used for providing +5V and +12V power supplies for the number 2 sub-control board and the number 3 drive board, the relay JR0, the relay JR1 and the relay JR1-1 are internally provided with a normally open contact, a normally closed contact and a common contact, and the

contacts

3 and 5 of the relay JR0 are used for switching on or off an end point of an echo sound box A, B so that the echo amplification circuit is connected with or disconnected from the echo sound box; 6 and 8 contacts of the relay JR0 are used for disconnecting or connecting a C, D point which is grounded in the echo amplifying circuit; the audio output by the classroom power amplifier is electrically connected with

pins

1 and 2 of a port P3, the

pins

1 and 2 of the port P3 are electrically connected with a normally closed contact of a relay JR1-1 through a normally closed contact of the relay JR1, the normally closed contact of the relay JR1-1 is connected with

pins

23, 24, 25 and 26 of a bus slot JA of a No. 2 sub-control panel, and is connected with the normally closed contact of a class relay J-x through

pins

2 and 3 of a connector Jx and is connected with a class broadcasting terminal RL-x through the normally closed contact;

the normally open contact of the relay JR1 is connected with

pins

3 and 4 of a connector PAX, the common contact of the relay JR1 is connected with the common contact of the relay JR1-1, the normally open contact of the relay JR1-1 is connected with

pins

21 and 22,

pins

27 and 28 of a bus slot JA of the number 2 sub-control board, then is connected with

pins

1 and 4 of the connector Jx of the number 2 sub-control board, and then is connected with the normally open contact of the class relay J-1;

pins

3 and 4 of the connector PAX are connected with the line-to-line transformer, are coupled to

pins

1 and 2 of the PAX through the line-to-line transformer and are connected with the echo amplifying circuit;

the singlechip ICs 1-x on the No. 2 sub-control board receive control levels of 9 and 10 pins from the IC3 at any time through the bus slot JA, and output control signals through

pins

1, 2, 3, 4, 5, 6, 7, 8, 12, 13, 14, 15, 16, 17, 21, 22, 23, 24, 25, 26, 27, 28, 32, 33, 34, 35, 36, 37, 38 and 39 of each singlechip IC1-x; the control pin of each single chip microcomputer IC1-x is connected with a photoelectric coupler U-x, each photoelectric coupler U-x is connected with a relay J-x, and each relay J-x is connected with a broadcasting terminal RL-x in a classroom.

As the optimization of the utility model, the single chip microcomputer IC4 and the single chip microcomputer IC7 on the number 1 main control board are respectively responsible for regional broadcasting and automatic music bell broadcasting in the region; the number 2 sub-control board is provided with 1 to 10 single-chip microcomputers IC1-x, and each single-chip microcomputer is connected with 2 number 3 drive boards; and 15 photoelectric couplers U-x,15 class relays J-x and 15 class broadcast terminals RL-x are mounted on the No. 3 driving plate.

As the utility model discloses a preferred, level shift chip IC 3's model is max232, level shift chip IC 3's 15 pin ground connections, 16 pin power connection +5v.

As an optimization of the utility model, the type of the single chip microcomputer IC7 is AT89S51, the TTL control signal from the computer is received by the pin 10 and the pin 11 of the single chip microcomputer IC7, the pin 40 of the single chip microcomputer IC7 is +5v power, the pin 20 is grounded, the pin 18 and the pin 19 of the single chip microcomputer IC7 are connected with a parallel oscillation circuit for generating 12MHz oscillation signals, and the parallel oscillation circuit is composed of C42, C43 and Y1; the models of the photoelectric couplers U1 to U5 are TIL113, the models of the relay JR0, the relay JR1 and the relay JR1-1 are AJW7211, and the model of the class relay J-x is HRS2H-S-DC12V.

As the utility model discloses a preferred, singlechip IC4 'S model is AT89S51, and singlechip IC 4' S40 pins are +5v power, and 40 pins are connected with C11, C12, C44, and C9, C10, L1, C11, C12, C44 carry out pi type filtering to power 40 pins, and singlechip IC4 'S20 feet ground connection, singlechip IC 4' S18, 19 pins connect parallelly connected oscillating circuit, parallelly connected oscillating circuit comprises C2, C3 and Y2.

As the utility model discloses an prefer, singlechip IC1-x 'S model is AT89S51, and singlechip IC 1-x' S40 pins are +5v power, 20 pin ground connections, and parallelly connected oscillating circuit is connected to 18, 19 pins.

As the optimization of the utility model, the echo amplifying circuit comprises a front-stage amplifying operational amplifier IC1, a rear-stage amplifying circuit IC2 and a voltage-stabilizing power supply for supplying power to the front-stage amplifying operational amplifier IC1 and the rear-stage amplifying circuit IC 2; wherein, the 3 pins of the pre-amplification operational amplifier IC1 are connected with the C14 pin and the 2 pins of the connector PAX pin, and then the line-to-line transformer is connected; pin 6 is connected with a +5V voltage-stabilized power supply, pin 4 is grounded, and pin 5 is sequentially connected with pin 6 of C19, potentiometers W1 and C21 and a rear-stage amplification circuit IC 2; and a pin 3 of the rear-stage amplification circuit IC2 is connected with the C22, a pin 2 of the rear-stage amplification circuit IC2 is connected with the +9V voltage-stabilized power supply, a pin 4 is grounded, and R16 provides bootstrap voltage for a pin 6.

As the utility model discloses an prefer, the model of preceding stage amplification operational amplifier IC1 is LM386, and the model of back stage amplifier circuit IC2 is 2822M, and the model of IC5 is L05, and the model of IC6 is 7809.

The utility model discloses an advantage and beneficial effect:

(1) Adopt the utility model provides a control circuit can inherit the advantage of former analog broadcast, the advantage of digital broadcast has also been possessed, this control circuit is under the control of computer, through the playground in the on/off school district, the corridor, the power of the power amplifier in classroom and the audio frequency of each class broadcast terminal of on/off, can realize broadcasting in the district, with arbitrary class two-way intercom, all classes make up the broadcast wantonly, the broadcast of grade group, the floor broadcast, functions such as whole building broadcast and school's broadcast, both provide more supervisory function for the school, abundant audio resource and high-quality audio effect, lower construction cost, also for the loss of school has reduced the electric energy, the hidden danger of electric shock and conflagration has been got rid of, unattended operation has been realized.

(2) The control circuit provided by the utility model can be independently installed outside the analog power amplifier case, and the control circuit is composed of a number 1 main control board, a number 1 sub-control board and a plurality of number 3 drive boards; the number 1 main control board is integrated with IC1, IC2, IC3, IC4, IC5, IC6 and IC7, and realizes regional broadcasting and automatic ringing by receiving control information output from a computer; 1-10 single-chip microcomputers IC1-x are integrated on the No. 2 sub-control board, and a proper number of single-chip microcomputers can be selected according to requirements; photoelectric couplers and class relays corresponding to the single-chip microcomputers IC1-x are mounted on the No. 3 driving board, each driving board comprises 15 photoelectric couplers and 15 class relays, and 15 broadcasting terminals can be controlled; each singlechip IC1-x is provided with two No. 3 drive boards (15 x2 broadcasting terminals), and 2-20 drive boards can be correspondingly and selectively installed to realize the control function of 30-300 terminals; if there are 55 classrooms in a certain school, under the condition that 1 # board remains unchanged, only need select to install 2 singlechips on 2 # board, 3 # board only needs to install 4, alright realize 60 classroom broadcastings, other needn't install, saved the cost.

(3) The utility model provides a level pressure power amplifier and broadcast terminal that control circuit used do not need special processing for the broadcasting equipment that market is commonly used.

(4) The utility model discloses a control circuit adopts centralized control, and output section passes through the broadcasting line (net twine or cable conductor) and directly is connected with broadcast terminal (do not have intermediate equipment), and equipment operation is stable, and is of high quality, and the processing ease, the fault rate is low, easy operation easy maintenance, and when the equipment uses, broadcasting line only has 0-110v alternating voltage, when not using, the circuit does not have the electricity, not only the power saving but also safety.

Drawings

Fig. 1 is a schematic diagram of a control principle of a control circuit of the present invention in embodiment 1;

FIG. 2 is a circuit diagram of a level conversion chip IC3 in embodiment 1;

fig. 3 is a circuit diagram of the chip IC7 in embodiment 1;

fig. 4 is a circuit diagram of the chip microcomputer IC4 in embodiment 1;

fig. 5 is a circuit diagram illustrating connections between D12 to D21 and U1 to U5 in embodiment 1;

fig. 6 is a circuit diagram of connection of U6 to U8 to a relay in embodiment 1;

fig. 7 is a schematic connection diagram of the number 1 main control board, the number 2 slave control board, and the number 3 drive board in embodiment 1;

fig. 8 is a diagram of a single class broadcast or class talk back broadcast signal transmission.

FIG. 9 is a schematic view showing connection of IC1-1 to drive board No. 3 in embodiment 1;

fig. 10 is a circuit diagram of an echo amplifying circuit;

fig. 11 is a circuit diagram of a circuit connected to the interface P4.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

In the description of the present application, it should be noted that the terms "in", "under", and the like indicate the orientation or positional relationship: the particular arrangements or components shown in the drawings, or the orientations or positional relationships conventionally used in the manufacture of the applications, are for convenience only and to simplify the description, and are not intended to indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular orientation, and are not to be construed as limiting the application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; they may be mechanically coupled, directly coupled, indirectly coupled through intervening media, or may be interconnected between two elements. The specific meaning of the above terms in this application will be understood to be a specific case for those of ordinary skill in the art.

Example 1

As shown in fig. 1 to 11, the utility model provides a control circuit for carrying out digital control on analog broadcasting, which comprises a number 1 main control board, a number 2 sub-control board electrically connected with the number 1 main control board, and a number 3 drive board electrically connected with the number 2 sub-control board; wherein, level conversion chip IC3, singlechip IC7, singlechip IC4, echo amplification circuit are installed on the No. 1 main control board; the No. 2 sub-control board is provided with N (1-10) single-chip microcomputers IC1-x; 15 photoelectric couplers U-x and 15 class relays J-x are mounted on the No. 3 driving plate;

pins

7 and 8 of the level conversion chip IC3 are connected with a computer to receive a control signal sent by the computer, pins 9 and 10 of the level conversion chip IC3 are connected with

pins

10 and 11 of a single chip IC4, a single chip IC7 and N (1-10) single chip ICs 1-x, the (+ 10v-10 v) level output by a computer serial port rs232 is transmitted to

pins

7 and 8 of the conversion chip IC3, and is converted into TTL signal level (0, + 5) used by the single chip microcomputer through the inside of the level conversion chip IC3 and is output from

pins

9 and 10 of the IC 3; the type of the IC3 is max232, a pin 15 of the IC3 is grounded, and a pin 16 of the IC3 is connected with a power supply +5v;

pins 10 (serial input port) and pins 11 (serial output port) of the singlechip IC7 receive TTL control signals from a computer, are identified and controlled by the singlechip IC7, and output control signals at

pins

24, 25, 26, 27 and 28; a pin 24 of the singlechip IC7 is electrically connected with a music bell control diode D21, and the music bell control diode D21 is electrically connected with a photoelectric coupler U5; pin 25 is electrically connected with a music bell control diode D20, and the music bell control diode D20 is electrically connected with a photoelectric coupler U4; pin 26 is electrically connected with a music bell control diode D19, and the music bell control diode D19 is electrically connected with a photoelectric coupler U3; the pin 27 is electrically connected with a music bell control diode D18, and the music bell control diode D18 is electrically connected with a photoelectric coupler U2; pin 28 is electrically connected to music bell control diode D17, and music bell control diode D17 is electrically connected to photocoupler U1.

The model of the singlechip IC7 is AT89C51, pin 40 of the singlechip IC7 is a +5v power supply, pin 20 is grounded, pins 18 and 19 of the singlechip IC7 are connected with a parallel oscillation circuit for generating 12MHz oscillation signals, and the parallel oscillation circuit is composed of C42, C43 and Y1.

The model of the photoelectric coupler U5, the photoelectric coupler U4, the photoelectric coupler U3, the photoelectric coupler U2 and the photoelectric coupler U1 is TIL113, the photoelectric coupler U5, the photoelectric coupler U4, the photoelectric coupler U3, the photoelectric coupler U2 and the photoelectric coupler U1 are electrically connected with a port P4, and the port P4 is electrically connected with a relay J5 for controlling a power supply of a power amplifier in the corridor 2, a relay J4 for controlling a power supply of a front power amplifier, a relay J3 for controlling a power supply of a playground power amplifier, a relay J2 for controlling a power supply of a classroom power amplifier and a relay J1 for controlling the power supply of the power amplifier in the corridor 1; the corridor 2 power amplifier, the playground power amplifier, the classroom power amplifier and the corridor 1 power amplifier are constant-pressure power amplifiers which are all electrically connected with audio output by the front power amplifier, the front power amplifier receives audio of a computer and a microphone, and the audio is amplified by bass and then is transmitted to the corridor 2 power amplifier, the corridor 1 power amplifier, the playground power amplifier and the classroom power amplifier, so that music bell broadcasting in an area is realized.

Pins 10 (serial input ports) and pins 11 (serial output ports) of the singlechip IC4 receive control signals from a computer, and control levels are output at pins 3, 4 and 5 and also output at pins 24, 25, 26, 27 and 28 through identification and control of the singlechip IC 4; a pin 24 of the singlechip IC4 is electrically connected with a broadcast control diode D16, and the broadcast control diode D16 is electrically connected with a photoelectric coupler U5; pin 25 is electrically connected with a broadcast control diode D15, and the broadcast control diode D15 is electrically connected with a photoelectric coupler U4; pin 26 is electrically connected with a broadcast control diode D14, and the broadcast control diode D14 is electrically connected with a photoelectric coupler U3; the pin 27 is electrically connected with a broadcast control diode D13, and the broadcast control diode D13 is electrically connected with a photoelectric coupler U2; the pin 28 is electrically connected with a broadcast control diode D12, and the broadcast control diode D12 is electrically connected with a photoelectric coupler U1; pins 3, 4 and 5 of the singlechip IC4 are respectively and electrically connected with a photoelectric coupler U6, a photoelectric coupler U7 and a photoelectric coupler U8, the photoelectric coupler U6 is electrically connected with a relay JR5V, the photoelectric coupler U7 is electrically connected with a relay JR0 and a relay JR1, and the photoelectric coupler U8 is electrically connected with a relay JR 1-1; the type of the singlechip IC4 is AT89S51, a 40 pin of the singlechip IC4 is a +5v power supply, the 40 pin is connected with C11, C12 and C44, the C9, C10, L1, C11, C12 and C44 carry out pi-type filtering on the 40 pin of the power supply, a 20 pin of the singlechip IC4 is grounded, 18 and 19 pins of the singlechip IC4 are connected with a parallel oscillating circuit, and the parallel oscillating circuit consists of C2, C3 and Y2;

the relay JR5V is used for providing +5V and +12V power supplies for the number 2 sub-control board and the number 3 driving board, the relay JR0, the relay JR1 and the relay JR1-1 are internally provided with normally open contacts, normally closed contacts and common contacts, the model is AJW7211, and the model of the class relay J-x is HRS2H-S-DC12V.

The 3 and 5 contacts of the relay JR0 are used for connecting or disconnecting the end point of the echo sound box A, B so as to connect or disconnect the echo amplifying circuit with the echo sound box; 6 and 8 contacts of the relay JR0 are used for disconnecting or connecting a C, D point which is grounded in the echo amplifying circuit;

the audio output by the classroom power amplifier is electrically connected with

pins

1 and 2 of a port P3, the

pins

23, 24, 25 and 26 of a bus slot JA of a No. 2 sub-control panel, then is connected with the normally closed contact of a class relay J-1 through

pins

2 and 3 of a connector Jx, and then is connected with a class broadcast terminal RL-1 through the normally closed contact.

The normally open contact of the relay JR1 is connected with the

pins

3 and 4 of the connector PAX, the common contact of the relay JR1 is electrically connected with the common contact of the relay JR1-1, the normally open contact of the relay JR1-1 is connected with the

pins

21 and 22, 27 and 28 of the bus slot JA of the sub-control board No. 2, then is connected with the

pins

1 and 4 of the connector Jx of the sub-control board No. 2, and then is connected with the normally open contact of the class relay J-1;

pins

the model of the singlechip IC1-x on the No. 2 sub-control board is AT89S51, the singlechip IC1-x receives control levels of

pins

9 and 10 from the IC3 AT any time through

interfaces

17, 18, 19 and 20 of the bus slot JA, and outputs control signals through

pins

1, 2, 3, 4, 5, 6, 7, 8, 12, 13, 14, 15, 16, 17, 21, 22, 23, 24, 25, 26, 27, 28, 32, 33, 34, 35, 36, 37, 38 and 39 of the singlechip IC 1-x. For example, when the computer runs an intelligent broadcasting program,

pins

3 and 5 of the singlechip IC4 are at low level, a photoelectric coupler U6 is conducted, a relay JR5V is attracted, and +5V and +12V power supplies are provided for a sub-control board No. 2 and a drive board No. 3; the U8 connected with the pin 5 is conducted, the relay JR1-1 is conducted, the normally closed contact is disconnected, and the normally open contact is closed; after the sub-control panel No. 2 obtains a power supply,

pins

1, 2, 3, 4, 5, 6, 7, 8, 12, 13, 14, 15, 16, 17, 21, 22, 23, 24, 25, 26, 27, 28, 32, 33, 34, 35, 36, 37, 38 and 39 of all single chip microcomputer ICs 1-x all output high levels, photocouplers U-x are not conducted, class relays are not attracted, and normally closed contacts are conducted.

15 photoelectric couplers U-x and 15 class relays J-x are mounted on the No. 3 driving board and connected with 15 broadcasting terminals RL-x; the single chip microcomputer IC1-1 is connected with two No. 3 driving boards through a bus slot P1 and a bus slot P2 to realize the control of 30 broadcasting terminals. In the actual use process, the number of the singlechips IC1-x arranged on the number 2 sub-control board can be selected according to the class number of the school, and the number 3 drive board is inserted into the number 2 sub-control board according to the result of multiplying the number of the singlechips IC1-x by 2, so that the control of the corresponding number of the broadcasting terminals can be realized; at most 10 single-chip microcomputers IC1-1 … … IC1-10 can be installed on the No. 2 sub-control board, so that the RL-x control of 30-300 classroom broadcast terminals can be realized.

The pin 40 of the single chip IC1-x is a +5v power supply, the pin 20 is grounded, and the

pins

18 and 19 are connected with the parallel oscillating circuit, so that the performance of the single chip IC1-x is consistent;

the echo amplifying circuit comprises a front-stage amplifying operational amplifier IC1, a rear-stage amplifying circuit IC2 and a stabilized voltage power supply for supplying power to the front-stage amplifying operational amplifier IC1 and the rear-stage amplifying circuit IC 2; the pin 3 of the pre-stage amplification operational amplifier IC1 is connected with the pin C14 and the pin 2 of the connector PAX, the inter-wire transformer is connected, the pin 6 is connected with the stabilized voltage power supply, the pin 4 is grounded, and the pin 5 is sequentially connected with the pin C19, the potentiometers W1 and C21 and the pin 6 of the post-stage amplification circuit IC 2; pin 3 of the rear-stage amplification circuit IC2 is connected with pin C22, pin 2 of the rear-stage amplification circuit IC2 is connected with a voltage-stabilized power supply, pin 4 is grounded, and pin R16 provides bootstrap voltage for pin 6.

Further, in the process of supplying power to the echo amplifying circuit, the two stages of IC5 (L7809) and IC6 (78L 05) voltage stabilizing circuits are adopted, and +5v and +9v power supplies are respectively taken out to supply power to IC1 (LM 386) and IC2 (2822M), and because the two stages of voltage stabilizing circuits are adopted for voltage reduction, and two stages of pi-type filtering are adopted, the echo sound box has pure sound and no hum; the model of the front-stage amplification operational amplifier IC1 is LM386, the model of the rear-stage amplification circuit IC2 is TDA2822M, the model of the IC5 is L05, and the model of the IC6 is L7809.

The speaking sound in class makes the RL (loudspeaker + line-to-line transformer) coil of the broadcast terminal generate weak audio current, the weak audio current passes through the J-x class relay, the Jx connector, the JA bus slot, the JR1-1 relay, the JR1 relay, the PAX connector and the line-to-line transformer and is fused, the weak audio current is accessed to the pin 3 of the IC1 (LM 386) through the C14 (1 uf) coupling capacitor, the R13, the R14, the C13 and the C15 form a pi-type filter circuit for removing noise picked up by a classroom loudspeaker box, the pin 6 provides a stable +5v power supply for the stable PAX coil, the pin 4 is grounded, the pin 5 outputs an amplified audio signal, the amplified audio signal is coupled to the potentiometer W1 through the C19, the strength of the signal is adjusted, the signal is coupled to the pin 6 of the IC2 through the C21, the amplified high power is output from the pin 3 and is coupled to the A, B (switch-on) point through the C22, and the echo sound in classroom is transmitted to the loudspeaker box, and the sound in class is heard.

The utility model discloses a theory of operation:

(1) Automatic music bell broadcast in area

The single chip microcomputer IC7 is controlled by a computer to output low levels at

pins

24, 25, 26, 27 and 28 (selectively), diodes D21 to D17 and photoelectric couplers U5 to U1 are controlled by a music bell to drive, corresponding relays J5 to J1, a relay J5 for controlling a power supply of a power amplifier in a corridor 2, a relay J4 for controlling a power supply of a front power amplifier, a relay J3 for controlling a power supply of a playground power amplifier and a relay J1 for controlling the power supply of the power amplifier in the corridor 1 are attracted, and the music bell is automatically played in an area when the corresponding power supply is switched on; when the music bell is not played, pins 24, 25, 26, 27 and 28 of the singlechip IC7 are all high level, and the driven relays J5 to J1 are all closed.

(2) Regional broadcast (Intelligent broadcast)

When the intelligent broadcasting program is opened, a 25 pin of the singlechip IC4 is controlled to be at a low level by a computer, the broadcasting control diode D15 is conducted, the photoelectric coupler U4 drives the relay J4 to suck, and the preposed power amplifier is opened; after clicking the buttons of the corridor 2, the playground and the corridor 1 by a mouse, pins 24, 26 and 28 of the computer control singlechip IC4 are changed from high level to low level, the broadcast control diode D16 (4148), the broadcast control diode D14 (4148), the broadcast control diode D12 (4148), the photoelectric coupler U5 (TIL 113), the photoelectric coupler U3 (TIL 113) and the photoelectric coupler U1 (TIL 113) are respectively connected with the relays J5, J3 and J1 through the port P4 to drive and control the relay suction of the power supplies of the power amplifier of the corridor 2, the playground power amplifier and the power amplifier of the corridor 1, and the power amplifier power supplies of the corridor 2, the playground and the corridor 1 are connected to realize the broadcasting in the areas of the school corridor 2, the playground or the corridor 1.

(3) Class individual broadcast, arbitrary combination broadcast, grade group broadcast

When the intelligent broadcasting program is opened,

pins

3 and 5 of the singlechip IC4 are at low level, a photoelectric coupler U6 is conducted, a relay JR5V is attracted, and +5V and +12V power supplies are provided for the sub-control board No. 2 and the drive board No. 3; the U8 connected with the pin 5 is conducted, the relay JR1-1 is conducted, the normally closed contact is disconnected, and the normally open contact is closed to prepare for independent broadcasting and answering; after the sub-control panel No. 2 obtains a power supply, pins 1, 2, 3, 4, 5, 6, 7, 8, 12, 13, 14, 15, 16, 17, 21, 22, 23, 24, 25, 26, 27, 28, 32, 33, 34, 35, 36, 37, 38 and 39 of all the single chip microcomputer ICs 1-x all output high levels, all the photoelectric couplers U-x are not conducted, and all the class relays are not attracted.

For a single class broadcast: when a certain class needs to be broadcasted independently, the singlechip IC1-1 … … IC1-10 receives an IC3 control signal, outputs a low level at a corresponding pin, is connected with a corresponding photoelectric coupler U-x, is attracted by a class relay J-x, is disconnected from a normally closed contact of the class relay J-x, is connected with a common end point and a normally open contact, and is connected with a class broadcasting terminal (a power audio signal output by a classroom power amplifier is input through

pins

1 and 2 of P3, is connected with a normally closed contact of a relay JR1, is connected with the normally open contact of the JR1-1, is connected with

pins

21, 22, 27 and 28 of a bus slot JA, is connected with

pins

1 and 4 of a connector Jx, and is connected with the normally open contact of the class relay J-x), so that single class broadcasting can be realized for a class; when broadcasting is needed to be carried out on a plurality of classes, corresponding pins of single-chip microcomputers IC1-1 … … IC1-10 of the plurality of classes all output low levels, corresponding photoelectric couplers U-x are switched on, class relays J-x are all attracted, normally open contacts are all switched on, selected class broadcasting terminals are switched on, and random combined broadcasting is achieved; through related operations, the functions of grade group broadcasting, floor broadcasting, whole-building broadcasting, whole-school broadcasting and the like can be realized.

(4) Two-way talkback function

Single class talk back broadcast: when a certain class is broadcasted independently, the broadcasting room can hear the return voice of the certain class through control. When the class call needs to be listened, under the condition of carrying out individual broadcasting on a certain class (classroom power amplifier audio-P3-relay JR1 normally closed contact-relay JR1-1 normally open contact-pins 21 and 22 and 27 and 28 of bus slot JA-pins 1 and 4 of connector Jx-class relay J-x normally open contact-class broadcasting terminal), clicking a 'call back' button by a mouse, outputting low level by 4 pins of a singlechip IC4 through computer control, conducting a photoelectric coupler U7 to conduct a relay JR0 (relay JR0 is conducted, contacts 3 and 5 of JR0 are conducted, an echo A, B end point is conducted, contacts 6 and 8 of the relay JR0 are disconnected, and a grounded C, D point in an echo amplifying circuit is disconnected), the relay JR1 is conducted (the normally closed contact is disconnected, the class power amplifier audio signal input by the P3 interface is cut off), the normally open contact of the relay JR1 is connected, the relay JR1 connects the audio signal input by the class broadcast terminal into the connector PAX, the audio signal picked up by the class broadcast terminal is sent to the line-to-line transformer and is connected with the echo amplification circuit, and a loop of class broadcasting terminal-class relay J-x normally open contact-1 and 4 pins of the connector Jx-21 and 22 pins and 27 and 28 pins of the bus slot JA-relay JR1-1 normally open contact-relay JR1 normally open contact-3 and 4 pins of the connector PAX-line-to-line transformer-echo amplification circuit-A, B end-echo sound box is formed, and class sound is heard. Under the independent broadcasting state, 4 pins of the singlechip IC4 output high level, and a normally closed contact of the relay JR1 is connected; when a single class returns, 4 pins of the singlechip IC4 output low level, and the normally open contact of the relay JR1 is switched on, so that the switching of the talking and the returning is realized.

In the echo amplifying circuit, R13, R14, C13, C15 IC1 constitute pi type filter circuit for removing the clutter that the classroom audio amplifier picked up, 6 pins provide stable +5v power for it, 4 pins ground connection.

Need to explain: the utility model discloses a control circuit controls through the software of installing on the computer, and the software of considering on the computer only is used for output control signal to control the pin output high level or the low level of above-mentioned each singlechip, consequently the utility model discloses do not any restriction to the software on the computer, the software that the all can be according to above-mentioned control process to control circuit output control signal all can.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the embodiments of the present invention, and not for limiting the same; although embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention.

Claims

1. A control circuit for carrying out digital control on analog broadcasting is characterized by comprising a No. 1 main control board, a No. 2 sub-control board electrically connected with the No. 1 main control board, and a No. 3 drive board electrically connected with the No. 2 sub-control board; the No. 1 main control board is provided with a level conversion chip IC3, a singlechip IC7, a singlechip IC4 and an echo amplification circuit; n single-chip microcomputers IC1-x are mounted on the No. 2 sub-control board; 15 photoelectric couplers U-x and 15 class relays J-x are mounted on the No. 3 driving plate;

pins 7 and 8 of the level conversion chip IC3 are connected with a computer, the rs232 signal level of a serial port of the computer is converted into a TTL signal used by the singlechip, and the TTL signal is connected with pins 10 and 11 of the singlechip IC4, the singlechip IC7 and N singlechips IC1-x through pins 9 and 10 of the IC 3;

a pin 24 of the singlechip IC7 is electrically connected with a music bell control diode D21, and the music bell control diode D21 is electrically connected with a photoelectric coupler U5; pin 25 is electrically connected with a music bell control diode D20, and the music bell control diode D20 is electrically connected with a photoelectric coupler U4; pin 26 is electrically connected with a music bell control diode D19, and the music bell control diode D19 is electrically connected with a photoelectric coupler U3; the pin 27 is electrically connected with a music bell control diode D18, and the music bell control diode D18 is electrically connected with a photoelectric coupler U2; pin 28 is electrically connected with music bell control diode D17, and music bell control diode D17 is electrically connected with photoelectric coupler U1;

the photoelectric coupler U5, the photoelectric coupler U4, the photoelectric coupler U3, the photoelectric coupler U2 and the photoelectric coupler U1 are electrically connected with a port P4, and the port P4 is electrically connected with a relay J5 for controlling a power supply of a power amplifier in the corridor 2, a relay J4 for controlling a power supply of a front power amplifier, a relay J3 for controlling a power supply of a playground power amplifier, a relay J2 for controlling a power supply of a classroom power amplifier and a relay J1 for controlling the power supply of the power amplifier in the corridor 1; the corridor 2 power amplifier, the playground power amplifier, the classroom power amplifier and the corridor 1 power amplifier are all constant-voltage power amplifiers and are all connected with audio output by the front power amplifier;

a 24 pin of the singlechip IC4 is electrically connected with a broadcast control diode D16, and the broadcast control diode D16 is electrically connected with a photoelectric coupler U5; pin 25 is electrically connected with a broadcast control diode D15, and the broadcast control diode D15 is electrically connected with a photoelectric coupler U4; pin 26 is electrically connected with a broadcast control diode D14, and the broadcast control diode D14 is electrically connected with a photoelectric coupler U3; the 27 pin is electrically connected with a broadcast control diode D13, and the broadcast control diode D13 is electrically connected with a photoelectric coupler U2; pin 28 is electrically connected with a broadcast control diode D12, and the broadcast control diode D12 is electrically connected with a photoelectric coupler U1; pins 3, 4 and 5 of the singlechip IC4 are respectively and electrically connected with a photoelectric coupler U6, a photoelectric coupler U7 and a photoelectric coupler U8, the photoelectric coupler U6 is electrically connected with a relay JR5V, the photoelectric coupler U7 is electrically connected with a relay JR0 and a relay JR1, and the photoelectric coupler U8 is electrically connected with a relay JR 1-1;

the relay JR5V provides +5V and +12V power supplies for the sub control board No. 2 and the drive board No. 3, the relay JR0, the relay JR1 and the relay JR1-1 are internally provided with normally open contacts, normally closed contacts and common contacts, and the contacts 3 and 5 of the relay JR0 are used for switching on or off the endpoint of the echo sound box A, B so that the echo amplification circuit is connected with or disconnected from the echo sound box; 6 and 8 contacts of the relay JR0 are used for disconnecting or connecting a C, D point which is grounded in the echo amplifying circuit; the audio output by the classroom power amplifier is electrically connected with pins 1 and 2 of a port P3, the pins 1 and 2 of the port P3 are electrically connected with a normally closed contact of a relay JR1-1 through a normally closed contact of the relay JR1, the normally closed contact of the relay JR1-1 is connected with pins 23, 24, 25 and 26 of a bus slot JA of a No. 2 sub-control board, then is connected with the normally closed contact of a class relay J-x through pins 2 and 3 of a connector Jx, and then is connected with a class broadcasting terminal RL-x through the normally closed contact;

the normally open contact of the relay JR1 is connected with the pins 3 and 4 of the connector PAX, the common contact of the relay JR1 is connected with the common contact of the relay JR1-1, the normally open contact of the relay JR1-1 is connected with the pins 21, 22, 27 and 28 of the bus slot JA of the sub-control board No. 2, then is connected with the pins 1 and 4 of the connector Jx of the sub-control board No. 2, and then is connected with the normally open contact of the class relay J-1; pins 3 and 4 of the connector PAX are connected with the line-to-line transformer, are coupled to pins 1 and 2 of the PAX through the line-to-line transformer and are connected with the echo amplifying circuit;

the singlechip ICs 1-x on the No. 2 sub-control board receive control levels from the pins 9 and 10 of the level conversion chip IC3 at any time through the bus slot JA, and output control signals through the pins 1, 2, 3, 4, 5, 6, 7, 8, 12, 13, 14, 15, 16, 17, 21, 22, 23, 24, 25, 26, 27, 28, 32, 33, 34, 35, 36, 37, 38 and 39 of each singlechip IC1-x; the control pin of each single chip microcomputer IC1-x is connected with a photoelectric coupler U-x, each photoelectric coupler U-x is connected with a class relay J-x, and each class relay J-x is connected with a broadcasting terminal RL-x in a classroom.

2. The control circuit for digitally controlling analog broadcasting according to claim 1, wherein the single chip microcomputer IC4 and the single chip microcomputer IC7 on the number 1 main control board are respectively responsible for area broadcasting and automatic music bell broadcasting in the area; the number 2 sub-control board is provided with 1 to 10 single chip microcomputers IC1-x, and each single chip microcomputer IC1-x is connected with 2 number 3 drive boards; and 15 photoelectric couplers U-x and 15 class relays J-x are mounted on the No. 3 driving board, and the 15 class relays J-x are respectively connected with 15 broadcasting terminals RL-x.

3. The control circuit for digitally controlling analog broadcasting according to claim 1, wherein the type of the level shift chip IC3 is max232, the pin 15 of the level shift chip IC3 is connected to ground, and the pin 16 is connected to +5v.

4. The control circuit for digital control of analog broadcasting as claimed in claim 1, wherein said single chip IC7 is AT89S51, pin 10 and pin 11 of the single chip IC7 receive TTL control signal from a computer, pin 40 of the single chip IC7 is +5v power supply, pin 20 is grounded, pin 18 and pin 19 of the single chip IC7 are connected to a parallel oscillating circuit for generating 12MHz oscillating signal, said parallel oscillating circuit is composed of C42, C43 and Y1; the models of the photocouplers U1 to U5 are TIL113.

5. The control circuit for digitally controlling analog broadcasting according to claim 1, wherein the type of the single chip microcomputer IC4 is AT89S51, a 40 pin of the single chip microcomputer IC4 is a +5v power supply, the 40 pin is connected with C11, C12 and C44, the C9, C10, L1, C11, C12 and C44 perform pi-type filtering on the 40 pin of the power supply, a 20 pin of the single chip microcomputer IC4 is grounded, 18 and 19 pins of the single chip microcomputer IC4 are connected with a parallel oscillation circuit, and the parallel oscillation circuit is composed of C2, C3 and Y2; the types of the relay JR0, the relay JR1 and the relay JR1-1 are AJW7211, and the type of the class relay J-x is HRS2H-S-DC12V.

6. The control circuit for digitally controlling analog broadcasting according to claim 1, wherein the type of the single chip microcomputer IC1-x is AT89S51, pin 40 of the single chip microcomputer IC1-x is +5v power, pin 20 is grounded, and pins 18 and 19 are connected to the parallel oscillating circuit.

7. The control circuit for digitally controlling analog broadcasting according to claim 1, wherein said echo amplifying circuit includes a pre-amplifying operational amplifier IC1, a post-amplifying circuit IC2, a regulated power supply for supplying power to the pre-amplifying operational amplifier IC1 and the post-amplifying circuit IC 2; the pin 3 of the pre-stage amplification operational amplifier IC1 is connected with the pin C14 and the pin 2 of the connector PAX, the inter-wire transformer is connected, the pin 6 is connected with the stabilized voltage power supply, the pin 4 is grounded, and the pin 5 is sequentially connected with the pin C19, the potentiometers W1 and C21 and the pin 6 of the post-stage amplification circuit IC 2; and a pin 3 of the rear-stage amplification circuit IC2 is connected with the C22, a pin 2 of the rear-stage amplification circuit IC2 is connected with the voltage-stabilized power supply, a pin 4 is grounded, and R16 provides bootstrap voltage for a pin 6.

8. The control circuit for digitally controlling analog broadcasting according to claim 7, wherein the former stage amplifier IC1 has a model LM386, the latter stage amplifier IC2 has a model 2822m, the latter stage amplifier IC5 has a model L05, and the later stage amplifier IC6 has a model 7809.