Design Operating Principle Of A Signal Generator Computer Science Essay

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In my report my task is actually to explain everything about signal generators, signal generators have been around many years and within this report i will explain the procedures how and whats the importance of signal generators. Signal generator is basically an electronic device which is able to (generate repeating or also non-repeating electronic signals) (change this line). However within this task the report will include the definitions of a signal generator, the basic outline of signal generator, the types of signal generator and an conclusion of this report.


The main purpose of signal generators is that it competent of sending signals into a circuit so it can be tested. (A technician looks at the signal at different points in the circuit with an oscilloscope, spectrum analyzer or other equipment. If the signal is distorted, attenuated or missing entirely, this will tell her what the circuit is doing. It is used to test systems of equipment, injecting a pure signal into a radio transmitter, for example. Analyzing the received signal cant tell a lot about the quality of both transmission and reception.

Definition of signal generator

Signal generator is basically a device which is able to generate repeated or non-repeated signals however this is mainly used in trouble shooting, and testing of an electronic equipments and also circuits. When testing signal generators it usually sends a calibrated frequency which can be a frequency of an audio to a microwave. This also depends on the usage of an instrument however the oscillator needs to have excellent frequency constancy and also depends on the constant over the tuning range.

The basic of signal generator

The basic of signal generator is that

The functions and operations of signal generator

Figure 1 shows a diagram of a signal generator, this is a PM 5106 lf generator Phillips model of 10 Hz - 100 kHz. This is diagram is quoted from the book 'Electronic instrumentation and measurements' and the writer is 'David Bell'.

Continuous frequency controlLF-Generator PM5106 ; Philips; - Eindhoven (ID = 148497) Equipment

Push-button range and sine/square wave selectors

Output connector

Power switch

Amplitude control and on/off switch

FIGURE 1, a low-frequency sine/square wave generator

Below shows how the signal generator is operated, and also shows what the functions do:

Sine/square wave selector - this is selected by pressing and releasing the left-hand push button, the sine/square wave selector contains four frequency ranges with the options of a minimum of 10 Hz - 100 Hz and the maximum of 10 kHz - 100 kHz.

Continuous frequency control - this control has an adjustment on each range which is provided by a large control knob and scale.

Amplitude control - the output amplitude has a continuously adjustable which is on two ranges, which are 0 - 0.1 V and 0 - 10V.

To set up a signal generator

Below will show how to set up a function generator, they are many types and models of signal generator however they all operate the same and also have similar controls. Figure 2 shows a diagram of a Thandar TG101 function generator. To set up a signal generator a oscilloscope Is also needed to test a circuit however below shows how an function generator is set up .

function generator

Figure 2 (

The first step to use a function generator is to select the type of wave shape. The wave types are sine, square or triangle shapes, the function generator contains a push button controls to select the switches. Then the task is an output of 600 Then this connected to CH1 input of the oscilloscope, this is done by using BNC - BNC lead. Figure 3 shows how they are connected:

connecting the function generator

The second step is to turn on the function generator and then adjust the output level to produce a visible signal which will be shown on the oscilloscope screen. Then the task is to adjust TIME/DIV and VOLTS/DIV to get a clear display and then explore the effects by pressing the waveform shape buttons.

The third step is to use a frequency of 50 Hz; this is done by changing the range to '100' and the frequency control to'.5'. This gives the frequency of an output signal; figure 4 shows a diagram of the frequency and range controls:

changing the frequency

It is important to explore these controls to produce different frequencies of other output signal such as 10Hz or 15Hz.

The other functions on the signal generator are often used less; however the 'sweep in' input is used to change output frequency by connecting appropriate signals. And the DC offset switch and the offset controls are use to add dc voltage components to output signal to produce complex waveform. (Might not need this information).

The fourth step is to switch the output level to 0dB, this is done to give an output signal with a peak amplitude which can be adjusted up to several volts. Figure 5 shows an close up of the output level switch:

Figure 5


Types of signal generators

There are several types signal generators which are used in different areas and different purposes. Signal generators are mainly important for users such as engineers, technicians and scientist which are used in their own experiments to test sine waves or square waves. The most common signal generator used which is generally used for scientific experiment is an "audio signal generator" which is used for testing sound. Scientist generally use audio signal generators whereas radio frequency (RF) are used by technicians, technicians use radio frequency usually for television and radio. The field which technician use radio frequency is broadcasters and communicators however there are other types of signal generators which are used by telephone and radar engineers, this type is a microwave signal generator. And the other type is a logic generator which is able to design computer circuits. Logic generators are used by digital engineers; nevertheless these two are really important generators to engineers since using these generators several times during an experiment. Below shows why these signal generators are important for the field which are applied to.

Audio signal generator - has a range of fixed waveforms which contain:




saw tooth

The audio generator are mainly used in wide range of frequencies, they are also used to test equipment towards its perimeter.

Radio - radio signal generators which produces two signals which has a frequency signal and a modulating signal, it covers a higher frequency range which is hundred of megahertz. This is used to test broadcasting gear

Microwave - A microwave signal generators is the most expensive signal generators then the others, this is because it produces frequencies which is cable of going into ten of gigahertz.

Logic -A logic signal generator is used to produce variety of high-frequency pulses modulated by data.

Main body about signal generator

Signal generator is basically is a device which is able to send electronic signals or in other words produces electrical impulses, however signal generator can be used in many sections within engineers such as testing, repairing testing electronics and acoustic devices. There are also many types of signal generator, the types are used for different purposes and also based on its functions, the main types of signal generators are arbitrary waveform and function and devices.

Function device

The most common used signal generator is function device; this device produces wave-like forms. Many engineers use this type of device for repairing and designing electronics. This device contains a circuit which is able to produce repeating wave which is also known as sine wave.

The function device is generally is connected to an oscilloscope so the device is able to send signals which then is able to test a present circuit. The oscilloscopes job is to then evaluate the output signal. The function device has many types of signal generators with different models and types to use for different appliances or use (electrical device).

Arbitrary waveform device

Arbitrary waveform is similar and also can be different to the function device, the similarities is that is it also produces forms however the arbitrary waveform is known for producing more waves then the function device. Arbitrary waveform has the ability to also produce different kind of waves which includes triangular, squares and rectangles waves. This device is also known for being the most expensive device form the other devices.

"Before people found signal device, they use similar device to produce signal. When people build a new radio station, they will measure another radio's performance as their standard. This radio measurement is called as "golden radio".

This method is cheaper and has a lot of advantages but they have one main disadvantage. This golden radio's performance is unstable. This condition makes golden radio can't be used as reliable equipment. You need to choose modern signal device to get the most accurate, precise and specific test equipment." (

Digital signal generator

Fig 4A digital signal generator is a special and very different signal generators to other signal devices, digital signal generators is able to use sound cards. Sound cards are used in signal generators to give output signal. Digital signal generator also has the ability to produce:

White noise signal

Sine wave

Square wave

Trigon wave

Beat wave

Sweep sine wave

Signal which is designed by a windows WAV file.

Fig 1 shows an example of a digital signal generator. (