CN207472934U - A kind of waveform signal generating system - Google Patents

Abstract

The utility model discloses a kind of waveform signal generating systems, including LCD driver modules, matrix keyboard, microcontroller, Frequency Band Selection circuit, duty ratio adjusting circuit, frequency fine tuning circuit, function signal generator, operational amplifier circuit, the LCD driver modules are connect with microcontroller, the matrix keyboard is connect with microcontroller, the microcontroller is connect with Frequency Band Selection circuit, the microcontroller is connect with Frequency Band Selection circuit, the Frequency Band Selection circuit, duty ratio adjusting circuit, the difference and function signal generator connection of frequency fine tuning circuit, the function signal generator is connect with operational amplifier circuit, the function signal generator uses MAX038.The combination that the utility model passes through LCD driver modules, matrix keyboard, microcontroller, Frequency Band Selection circuit, duty ratio adjusting circuit, frequency fine tuning circuit, function signal generator, operational amplifier circuit, simplied system structure, cost is reduced, the flexibility of control mode is provided.

Description

A kind of waveform signal generating system

Technical field

The utility model is related to signal generators, and in particular to a kind of waveform signal generating system.

Background technology

Signal generator is also referred to as signal source, is a kind of instrument for generating oscillator signal, needs are provided for user Stable, believable reference signal, and the characteristic parameter of signal is fully controllable.So-called controllable signal feature, is primarily referred to as exporting The parameters such as frequency, amplitude, waveform, duty ratio, the modulation format of signal can artificially control setting.With the hair of science and technology Exhibition, the signal form applied to is more and more, becomes increasingly complex, and frequency is also higher and higher, so the kind of signal generator Class is also more and more, and the circuit structure form of synchronous signal generator is also constantly towards intelligence, software implementation, programmable hair Exhibition.

With the rapid development of electronic surveying and other departments to the widespread demand and electronic technology of various types of signal generator, Signal generator type is promoted to increase, performance improves.Especially as the appearance of microprocessor, more promote signal generator towards certainly Dynamicization, intelligent direction development.Now, signal generator carries microprocessor, thus has self-correcting, self-test, automatic fault Diagnosis and automatic waveform formation and the functions such as correct, can easily be formed together with control computer and other measuring instruments from Dynamic test system.The total trend of current demand signal generator be towards broadband covering, low-power consumption, high-frequency, precision, it is multi-functional, Automation and intelligent direction development.In scientific research, engineering education and production practices, as industrial stokehold, teaching are real Test, mechanical oscillation experiment, dynamic analysis, the testing of materials, the fields such as biomedicine, it is often necessary to use low frequency generator. And in our daily lifes and in some scientific researches, sawtooth wave and sine wave, square-wave signal are common basic surveys Trial signal.For example in the instruments such as oscillograph, television set, in order to which electronics is made to be moved according to certain rule, to utilize fluorescence screen display Diagram picture commonly uses sawtooth generator as time base circuit.Signal generator is as a kind of general electronic instrument, in life The fields such as production, scientific research, observing and controlling, communication, which are obtained for, to be widely applied.But the instrument that can be seen on the market is in frequency accuracy, band Wide, waveform catalog and program-controlled aspect all have been unable to meet the demand of many aspect practical applications.In addition the semiconductor of types of functionality The quick production of integrated chip, all makes us develop a kind of low-power consumption, broadband, can generate multiple waveforms and with program-controlled etc. low The signal generator of frequency is possibly realized.But traditional signal generator is most of of high cost, and control mode is dumb, it is impossible to meet Present requirement.

Utility model content

Technical problem to be solved in the utility model is that traditional signal generator is most of of high cost, and control mode is not Flexibly, and it is an object of the present invention to provide a kind of waveform signal generating system, simplied system structure reduce cost, the spirit of control mode is provided Activity.

The utility model is achieved through the following technical solutions：

A kind of waveform signal generating system, including LCD driver modules, matrix keyboard, microcontroller, Frequency Band Selection electricity Road, duty ratio adjusting circuit, frequency fine tuning circuit, function signal generator, operational amplifier circuit, the LCD driver modules with Microcontroller connects, and the matrix keyboard connect with microcontroller, and the microcontroller is connect with Frequency Band Selection circuit, the microcontroller and Frequency Band Selection circuit connects, the Frequency Band Selection circuit, duty ratio adjusting circuit, frequency fine tuning circuit difference and function signal letter The connection of number generator, the function signal generator are connect with operational amplifier circuit, and the function signal generator is using MAX038.

Further, Frequency Band Selection circuit includes digital control analog switch U1, resistance R1, potentiometer R3, capacitance C1, electricity Hold C2, capacitance C3, capacitance C4, capacitance C5, capacitance C6, capacitance C7, capacitance C8, the digital control analog switch U1 uses CD4051, described capacitance C1 one end connect 13 pins of digital control analog switch U1, other end ground connection；Described capacitance C2 one end Connect 14 pins of digital control analog switch U1, other end ground connection；Described capacitance C3 one end connects digital control analog switch 15 pins of U1, other end ground connection；Described capacitance C4 one end connects 12 pins of digital control analog switch U1, another termination Ground；Described capacitance C5 one end connects 1 pin of digital control analog switch U1, other end ground connection；Capacitance C6 one end connection 5 pins of digital control analog switch U1, other end ground connection；Described capacitance C7 one end connects the 2 of digital control analog switch U1 Pin, other end ground connection；Described capacitance C8 one end connects 4 pins of digital control analog switch U1, other end ground connection；The electricity Position device R3 mono- fixes termination 5V power supplys, another fixing end ground connection, movable end connection resistance R1；Resistance R1 connection potentiometer R3 ends 10 pins of other end contiguous function generator；The 5 of the 3 pin and function signal generators of the digital control analog switch U1 Pin connects.

Further, operational amplifier circuit includes potentiometer R9, resistance R10, resistance R11, resistance R12, amplifier U3, the electricity A fixing end contiguous function signal generator of position device R9, another fixing end ground connection；Resistance R10 one end connection potentiometer R9 Movable end, the positive input of other end connection amplifier U3, resistance R11 and resistance R12 series connection, resistance R11 connections are electric Hinder the other end ground connection at R12 ends, the output terminal of the other end connection amplifier U3 at resistance R12 connection resistance R11 ends；Amplifier U3 Reverse input end end be connected on the circuit that resistance R11 is connect with resistance R12.

The utility model compared with prior art, has the following advantages and advantages：The utility model is shown by LCD Show drive module, matrix keyboard, microcontroller, Frequency Band Selection circuit, duty ratio adjusting circuit, frequency fine tuning circuit, function signal The combination of generator, operational amplifier circuit, simplied system structure reduce cost, provide the flexibility of control mode.

Description of the drawings

Attached drawing described herein is used for providing further understanding the utility model embodiment, forms the one of the application Part does not form the restriction to the utility model embodiment.In the accompanying drawings：

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

Fig. 2 is the utility model Frequency Band Selection circuit；

Fig. 3 is the utility model operational amplifier circuit.

Specific embodiment

For the purpose of this utility model, technical solution and advantage is more clearly understood, with reference to embodiment and attached drawing, The utility model is described in further detail, and the exemplary embodiment and its explanation of the utility model are only used for explaining this Utility model is not intended to limit the scope of the present invention.

Embodiment

As shown in Figure 1 to Figure 3, a kind of waveform signal generating system, including LCD driver modules, matrix keyboard, monolithic Machine, Frequency Band Selection circuit, duty ratio adjusting circuit, frequency fine tuning circuit, function signal generator, operational amplifier circuit, the LCD are shown Showing that drive module is connect with microcontroller, the matrix keyboard is connect with microcontroller, and the microcontroller is connect with Frequency Band Selection circuit, The microcontroller is connect with Frequency Band Selection circuit, the Frequency Band Selection circuit, duty ratio adjusting circuit, frequency fine tuning circuit difference And function signal generator connects, and the function signal generator is connect with operational amplifier circuit, the function signal generator Using MAX038.

Frequency Band Selection circuit includes digital control analog switch U1, resistance R1, potentiometer R3, capacitance C1, capacitance C2, capacitance C3, capacitance C4, capacitance C5, capacitance C6, capacitance C7, capacitance C8, the digital control analog switch U1 use CD4051, the electricity Hold 13 pins that C1 one end connects digital control analog switch U1, other end ground connection；Capacitance C2 one end connection is digital control 14 pins of analog switch U1, other end ground connection；Described capacitance C3 one end connects 15 pins of digital control analog switch U1, separately One end is grounded；Described capacitance C4 one end connects 12 pins of digital control analog switch U1, other end ground connection；The capacitance C5 mono- End connects 1 pin of digital control analog switch U1, other end ground connection；Described capacitance C6 one end connects digital control analog switch 5 pins of U1, other end ground connection；Described capacitance C7 one end connects 2 pins of digital control analog switch U1, other end ground connection； Described capacitance C8 one end connects 4 pins of digital control analog switch U1, other end ground connection；The potentiometer R3 mono- fixes termination 5V power supplys, another fixing end ground connection, movable end connection resistance R1；The other end contiguous function hair at resistance R1 connection potentiometer R3 ends 10 pins of raw device；The 5 pins connection of the 3 pin and function signal generators of the digital control analog switch U1.

Operational amplifier circuit includes potentiometer R9, resistance R10, resistance R11, resistance R12, amplifier U3, the potentiometer R9's One fixing end contiguous function signal generator, another fixing end ground connection；The activity of resistance R10 one end connection potentiometer R9 End, the positive input of other end connection amplifier U3, resistance R11 and resistance R12 series connection, resistance R11 connection resistance R12 ends Other end ground connection, the other end at resistance R12 connection resistance R11 ends connects the output terminal of amplifier U3；Amplifier U3's is reversed Input terminal end is connected on the circuit that resistance R11 is connect with resistance R12.

Signal generator controls MAX038 chips using microcontroller, carries out waveform selection, frequency bins and wave form Display.Microcontroller is by controlling CD4051 chips to select different capacitances, so as to select different frequency ranges, then by adjusting slip Frequency is adjusted in rheostat.Digital quantity is converted into analog quantity by microcontroller by DAC0832 analog-digital chips, controls wave The duty ratio of shape.And the amplitude of the waveform signal of output is amplified, 1602LCD is controlled to waveform shape finally by microcontroller Formula is shown.The capacitance of 8 channels capacitance different from 8 of CD4051 is connected, 8 capacitances are respectively listed electricity Hold.It is exactly a frequency range when one of channel is strobed, the Enable Pin INH of CD4051 chips is grounded, makes CD4051 cores Piece can work normally.Microcontroller is connected with CD4051 address pins A0~A2, and the selection of frequency range is carried out by microcontroller, then leads to Slide rheostat R3 is overregulated, IIN pins is allow to obtain the voltage of 0.5V~5V.IIN pins electricity is flowed into so as to reach to adjust The size of stream achievees the purpose that adjust frequency.Make a termination+5V voltages of slide rheostat, make R1=50k Ω, this is because The value of this resistance can be corresponding with maximum voltage+5V.Obtained electric current is 10 integral multiple relation, this is convenient for making capacitance Value is also 10 integral multiple relation.The resistance value make capacitance can selection range it is larger.Make the output of capacitance at every simultaneously Every 10 times just corresponding voltage range be from 0.5V to 5V.Frequency in each frequency range can be adjusted continuously, So as to fulfill frequency continuously adjusting from 0.1Hz~20MHz.

The digital quantity that microcontroller is sent is converted into analog output by DAC0832 analog-digital chips, but DAC0832 numbers The analog quantity of mould conversion chip output is current value, and control MAX038 chip output waveform duty ratios is voltage value, so Need design one that current value is converted into voltage value circuit, then the DADJ pins that voltage will be controlled to be connected to MAX038 chips.It reaches To the purpose for adjusting waveform duty cycle.The P3 mouths of microcontroller with the input terminal of DAC0832 are connected, is adjusted and inputted by button The size of DAC0832 chip digital amounts, so as to achieve the purpose that adjust DADJ pin voltages.In signal generator, DAC0832 By the way of straight-through, directly CS, 1WR, XFER, 2WR pin are grounded.Because the adjusting voltage of the duty ratio of MAX038 For -2.3V~+2.3V, so setting the reference voltage of the Vref of DAC0832 as+2.3V.Because supply voltage is+5V, pass through It adjusts slide rheostat and obtains+2.3V voltages.Because DAC0832 is the D/A converter part of eight, the resolution of DAC0832 Rate is 1/255=0.39%.Resolution ratio or quite high.Because the output signal of DAC0832 is current signal, we An operational amplifier circuit must be designed, current signal is converted into voltage signal.

Above-described specific embodiment, the purpose of this utility model, technical solution and advantageous effect have been carried out into One step is described in detail, it should be understood that the foregoing is merely specific embodiment of the present utility model, is not used to limit Determine the scope of protection of the utility model, within the spirit and principle of the utility model, any modification for being made equally is replaced It changes, improve, should be included within the scope of protection of this utility model.

Claims (3)

1. a kind of waveform signal generating system, which is characterized in that including LCD driver modules, matrix keyboard, microcontroller, frequency Section selection circuit, duty ratio adjusting circuit, frequency fine tuning circuit, function signal generator, operational amplifier circuit, the LCD displays are driven Dynamic model block is connect with microcontroller, and the matrix keyboard is connect with microcontroller, and the microcontroller is connect with Frequency Band Selection circuit, described Frequency Band Selection circuit, duty ratio adjusting circuit, the difference and function signal generator connection of frequency fine tuning circuit, the function Signal generator is connect with operational amplifier circuit, and the function signal generator uses MAX038.

2. a kind of waveform signal generating system according to claim 1, which is characterized in that Frequency Band Selection circuit includes number Control analog switch U1, resistance R1, potentiometer R3, capacitance C1, capacitance C2, capacitance C3, capacitance C4, capacitance C5, capacitance C6, capacitance C7, capacitance C8, the digital control analog switch U1 use CD4051, and described capacitance C1 one end connects digital control analog switch 13 pins of U1, other end ground connection；Described capacitance C2 one end connects 14 pins of digital control analog switch U1, another termination Ground；Described capacitance C3 one end connects 15 pins of digital control analog switch U1, other end ground connection；Capacitance C4 one end connection 12 pins of digital control analog switch U1, other end ground connection；Described capacitance C5 one end connects the 1 of digital control analog switch U1 Pin, other end ground connection；Described capacitance C6 one end connects 5 pins of digital control analog switch U1, other end ground connection；The electricity Hold 2 pins that C7 one end connects digital control analog switch U1, other end ground connection；Described capacitance C8 one end connects digital control mould Intend 4 pins of switch U1, other end ground connection；The potentiometer R3 mono- fixes termination 5V power supplys, another fixing end ground connection, movable end Connect resistance R1；10 pins of the other end contiguous function generator at resistance R1 connection potentiometer R3 ends；The digital control mould Intend the 5 pins connection of the 3 pin and function signal generators of switch U1.

3. a kind of waveform signal generating system according to claim 1, which is characterized in that the operational amplifier circuit includes current potential Device R9, resistance R10, resistance R11, resistance R12, amplifier U3, the potentiometer R9 a fixing end contiguous function signal hair Raw device, another fixing end ground connection；The movable end of resistance R10 one end connection potentiometer R9, other end connection amplifier U3's Positive input, resistance R11 and resistance R12 series connection, the other end ground connection at resistance R11 connection resistance R12 ends, resistance R12 connections The output terminal of the other end connection amplifier U3 at resistance R11 ends；The reverse input end of amplifier U3 is connected to resistance R11 and resistance On the circuit of R12 connections.