Urgent Help with AM Modulator Circuit - Resistor Value Assistance Needed

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In summary, The conversation discusses the need for urgent help with creating an AM modulator circuit for an upcoming exhibition at a university. The speaker is a level 2 student and has been given a circuit diagram from their seniors, but lacks the necessary knowledge to calculate missing resistor values. They mention the use of a 1 megahertz oscilator and suggest using a 4093 or 40106 Smittrigger as a quick substitute. The speaker also suggests using a 4051 to make multiple calls through one line. Amplitude modulation is explained as a method of communication and the use of a receiver to filter the 1 megahertz signal to retrieve the original sound.
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aruna1
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urgent help with AM modulator

hello friends;
we have an exhibition in my university.my seniors asked me to make a AM modulator circuit to demonstrate AM modulation.They also provided me a circuit diagram of a AM modulator(level 4 lab sheet),But in that diagram some resistor values are not mentioned.I don't know how to calculate them because AM modulation is will be taught in next year and I have no idea about AM modulation.(I'm a level 2 student)


I'm attaching the diagram I have,Can some one take a look at it and help me to find missing values

PS
I have only today to make this circuit so quick help would be great
 

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You need a 1 megahertz oscilator. The most important part is the RC-time.
A quick stand in can also be a 4093 or a 40106 Smittrigger. An inverter makes a 0 to 1 and a one to zero. The smittrigger does this in a very special way. It has hysteresis.
I think a smitttrigger (v=5 volt) goes off at 2,32 volt and goes on at 2,3.
At the input of the smittrigger comes a triangle voltage betwee these to vaulues. at the output comes a full swing of nearly 5 volt.

A very nice way could be a 4051, which can bring a input to one of eight channels.
It is not the requested A type full multiplexer, but it can bring a B type Amplitude modulation...
 
  • #3


ok didnt understand a bit
 
  • #4


Amplitude modulation is a way of communication. An oscilator of a certain frequency, in your case a 1 megahertz block switches form zero volt to 5 volt one million times a second.

A function with a frequency slower than this block (50 hertz<sound?<10.000 hertz) is to be communicated. If you sample the wave with the oscilator you get a function of changing amplitude. This signal can be transmitted. At the other side there is a receiver which can tune to 1 mehahertz. The receiver connects the samples with little lines (as you do when you draw graphs) physically this means filtering the 1 megahertz out of the signal and the receiver has the original sound.

For telefone things it is also usefull to have different calls through one line. The 4051 can make eight different call's through one line.
 

1. What is an AM modulator?

An AM (Amplitude Modulation) modulator is an electronic circuit that is used to add information to a carrier wave in order to transmit signals. It works by varying the amplitude of the carrier wave to carry the information.

2. How does an AM modulator work?

An AM modulator works by taking a high frequency carrier wave and combining it with a lower frequency signal (such as audio or video) to produce a modulated wave. The modulated wave is then transmitted through a medium such as air or a cable.

3. What is the purpose of an AM modulator?

The purpose of an AM modulator is to transmit information (such as audio or video) over long distances through a carrier wave. This allows for efficient and reliable communication between two points.

4. What are the components of an AM modulator?

An AM modulator typically consists of a carrier wave source, a modulating signal source, a mixer, and an amplifier. The carrier wave and modulating signals are combined in the mixer, and the resulting modulated signal is amplified before being transmitted.

5. Are there any common issues with AM modulators?

Yes, there are several common issues that can occur with AM modulators, such as distortion of the modulated signal, interference from other signals, and improper tuning of the carrier wave. It is important to properly calibrate and maintain the equipment to avoid these issues.

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