CN207662977U - Intelligent broadcast load detecting circuit - Google Patents

Abstract

The utility model discloses a kind of intelligent broadcast load detecting circuits, including four parts, respectively frequency generator circuit, signal amplification circuit, load detecting switching circuit and precise rectification circuit, frequency generator circuit sends out the signal of certain frequency as loudspeaker testing source, the signal of signal source is suitably amplified by signal amplification circuit, subsequently into load detecting switching circuit, detection signal is converted into signal DEC-, signal DEC- is carried out again by U2A after suitably amplifying, into precise rectification circuit, signal DEC- is converted into the DC voltage DECAD of ripple very little, DEC enters the AD detection pin detections of microcontroller.Using the circuit of the utility model, the detection each loaded can be easily completed, efficiency is 100 times of artificial detection or more.

Description

Intelligent broadcast load detecting circuit

Technical field

The utility model is related to a kind of detection circuit structures, and in particular to a kind of intelligent broadcast load detecting circuit.

Background technology

Intelligent broadcast is army, enterprise, the essential publicity broadcast tool of the units such as school.There are one special for this equipment Point is exactly that a power amplifier needs docking much a loudspeaker terminals, and after installation is complete, the state of detection loud-speaker load is one Very troublesome work.Conventional at present is by being manually detected using machinery equipment, existing and detect slow, the artificial shadow of result Ring big, the low problem of efficiency.

Utility model content

The purpose of the utility model is to overcome the defect of the prior art, provide a kind of simple in structure, detection efficiency is high Intelligent broadcast load detecting circuit.

The utility model is realized in this way：

Intelligent broadcast load detecting circuit, including four parts, respectively frequency generator circuit, signal amplification circuit, Load detecting switching circuit and precise rectification circuit, the signal that frequency generator circuit sends out certain frequency test letter as loudspeaker Number source, the signal of signal source are suitably amplified by signal amplification circuit, subsequently into load detecting switching circuit, will detect signal Signal DEC- is converted to, signal DEC- is carried out again by U2A after suitably amplifying, into precise rectification circuit, by signal The DC voltage DECAD, DEC that DEC- is converted into ripple very little enter the AD detection pin detections of microcontroller.

Further scheme is：

The frequency generator circuit includes clock chip U1, and 32.768KHz signals are exported in the P1 pins of U1, output 32.768KHz signal is as loudspeaker testing source.

Further scheme is：

The signal of loudspeaker testing source, entering signal amplifying circuit, couples by C5, and fortune is sent by input resistance R2 Amplifier is calculated, feedback resistance R10 is adjusted, the amplitude of output signal is:Vo=-R14/R13Vi；Amplify by signal amplification circuit Signal afterwards is sent to load detecting switching circuit by E1.

Further scheme is：

The load SPK1 of load detecting switching circuit is connected in the central contact of output relay J1.

Using the circuit of the utility model, the detection each loaded can be easily completed, efficiency is the 100 of artificial detection Times or more.

Description of the drawings

FIG. 1 is a schematic structural view of the utility model.

Specific implementation mode

The utility model is further described in the following with reference to the drawings and specific embodiments.

As shown in Fig. 1, intelligent broadcast load detecting circuit, including tetra- parts ABCD, wherein part A is frequency Device circuit, part B are signal amplification circuit, and the parts D are load detecting switching circuit, and C portion is precise rectification circuit and detection Pin,

Part A-frequency generator circuit

The main function of signal generator circuit is the alternating signal of frequency required for generating, this AC signal is final Detect the signal source of load.For acoustic angle, it is less than 20Hz and the frequency higher than 20KHz, the ear of people is not heard. So the frequency of selection 20KHz~40KHz can reach the requirement of the signal for detection.Requirement based on least cost, The signal of fixed frequency and fixed amplitude can be exported by the I/O port of microcontroller, the frequency that clock chip can also be used to carry Output pin.By software configuration, the signal of the continual output fixed frequency and fixed amplitude of chip is allowed.

Clock chip U1 is used in the utility model, by corresponding software configuration, is exported from the P1 pins of U1 32.768KHz signals.

This frequency needs to meet claimed below：Frequency stabilization, amplitude stabilization.

Part B-signal amplification circuit

The signal to come from signal source, amplitude are likely to be breached the amplitude less than needs, need to be amplified satisfaction test Required amplitude.Meanwhile amplifier also has the function of increasing carrying load ability.

The signal of signal source, is coupled by C6, is sent into operational amplifier by input resistance R3, is adjusted feedback resistance R4, The amplitude of output signal is:Vo=-R14/R13Vi (Vi is the input signal of signal source).

D part-load detecting switching circuits

By the amplified signal of part B, the parts D are sent to by E1.

Load SPK1 is connected in the central contact of output relay J1.When normal work, the power signal (sound that can be heard Sound signal) from " the power amplifier output+" and " power amplifier output-" of J1 normally opened contacts, it is connected to load (loud speaker).It is negative when needing to know When whether load is normal, the central contact of relay J1 is switched to by normally-closed contact by microcontroller.Normally-closed contact connecting detection is believed Number.Detection signal is flowed by loading one end, then is flowed out from other end DEC-.Outflow end DEC- meets a resistance R9 to reference Point.So outflow terminal voltage Vdec=Vo × R9/ (R9+R_SPK1)。

C portion-precise rectification circuit and detection pin

By the signal DEC- of the parts D out, the AD detection sensitivities according to microcontroller are needed, are carried out again by U2A Appropriate amplification.Enter precise rectification circuit using C7.The effect of precise rectification circuit is that exchange is converted into ripple very little DC voltage DECAD.DEC enters the AD detection pins of microcontroller.

It is AD converted by software, obtains determining AD values.Have following three kinds of situations：

1. when load open circuit (not loading access), the DEC- of the parts D is datum, and obtained AD values are 0.

2. when load short circuits (it is 0 Europe resistance to be equivalent to load), DEC- input voltage values (the part B E1 outputs of the parts D Value), obtained AD values are maximum.

3. when being supported in normal range (NR), the AD values that the DEC- of the parts D is obtained must be between AD values 1. 2..

" one embodiment " for being spoken of in the present specification, " another embodiment ", " embodiment " etc., refer to combining Specific features, structure or the feature of embodiment description are included at least one embodiment generally described herein. It is not centainly to refer to the same embodiment that statement of the same race, which occur, in multiple places in the description.Furthermore, it is understood that in conjunction with any When embodiment describes a specific features, structure or feature, what is advocated is that this spy is realized in conjunction with other embodiment Sign, structure or feature are also fallen in the scope of the utility model.

Although reference be made herein to the utility model is described in multiple explanatory embodiments of the utility model, still, It should be understood that those skilled in the art can be designed that a lot of other modification and implementations, these modifications and implementations It will fall within scope and spirit disclosed in the present application.More specifically, it discloses in the application, drawings and claims In range, a variety of variations and modifications can be carried out to the building block and/or layout of theme combination layout.In addition to building block And/or outside the variations and modifications of layout progress, to those skilled in the art, other purposes also will be apparent.

Claims (4)

1. intelligent broadcast load detecting circuit, including four parts, it is characterised in that：Respectively frequency generator circuit, signal Amplifying circuit, load detecting switching circuit and precise rectification circuit, frequency generator circuit, which sends out signal and tested as loudspeaker, to be believed Number source, the signal of signal source are suitably amplified by signal amplification circuit, subsequently into load detecting switching circuit, will detect signal Signal DEC- is converted to, signal DEC- is carried out again by U2A after suitably amplifying, into precise rectification circuit, by signal DEC- is converted into DC voltage DECAD, DEC and enters the AD detection pin detections of microcontroller.

2. intelligent broadcast load detecting circuit according to claim 1, it is characterised in that：

The frequency generator circuit includes clock chip U1, and 32.768KHz signals are exported in the P1 pins of U1, output 32.768KHz signal is as loudspeaker testing source.

3. intelligent broadcast load detecting circuit according to claim 2, it is characterised in that：

The signal of loudspeaker testing source, entering signal amplifying circuit, couples by C5, and being sent into operation by input resistance R2 puts Big device, adjusts feedback resistance R10, and the amplitude of output signal is:Vo=-R14/R13Vi；It is amplified by signal amplification circuit Signal is sent to load detecting switching circuit by E1.

4. intelligent broadcast load detecting circuit according to claim 1, it is characterised in that：

The load SPK1 of load detecting switching circuit is connected in the central contact of output relay J1.