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Hello, I can not handle a problem which is about AGC. Please help me about that. The conditions are; It is required to design and implement an AGC circuit with the following specifcations:

1=2E Amplitude of the input voltage may vary between 10 mVpp and 50 mVpp.

2=2E Amplitude of the output voltage should be in the range 0.9 Vpp and1.1 V pp for the input signals with amplitudes stated above.

3=2E Output impedance of the ampli=AFer should be smaller than 2 k=AD.

4=2E The circuit should be able to amplify the signals having frequencies

between 500 Hz and 10000 Hz.

The amplifer designed should be a single transistor amplifer in the common-emitter form for BJT amplifers or common-source form for the FET amplifers. However, it can be used extra transistors for making the

And the AGC should be composed of 2 parts adjustable gain part and feedback part.

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If you're waiting for us to do your homework for you, you're going to be waiting quite awhile. On the other hand, if you've had a good try at it and are just stuck on one or two things, your odds are better. Posting from a real email account (not Gmail or hotmail) will improve your odds further.

What have you actually done so far?

Cheers,

Phil Hobbs

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try posting to sci.electronics.homework

martin

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Hello, I can not handle a problem which is about AGC. Please help me about that. The conditions are; It is required to design and implement an AGC circuit with the following specifcations:

1=2E Amplitude of the input voltage may vary between 10 mVpp and 50 mVpp.

2=2E Amplitude of the output voltage should be in the range 0.9 Vpp and1.1 V pp for the input signals with amplitudes stated above.

3=2E Output impedance of the ampli=AFer should be smaller than 2 k=AD.

4=2E The circuit should be able to amplify the signals having frequencies

between 500 Hz and 10000 Hz.

The amplifer designed should be a single transistor amplifer in the common-emitter form for BJT amplifers or common-source form for the FET amplifers. However, it can be used extra transistors for making the

And the AGC should be composed of 2 parts adjustable gain part and feedback part.

• posted

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Hello, Thanks, but I can not send it to sci.electronics.homework Could you help me how can I send it? Thanks again.

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Hint #1: for low distortion, keep the AC voltage across the JFET used to control the gain as low as you reasonably can.

Hint #2: Have that JFET handle AC only, no DC, in order to offer a reasonably linear resistance.

Hint #3: With a high load impedance, silicon diodes conduct enough to offer significant rectification much below 0.7 volts.

Consider other topologies than you have so far. For example, consider using the FET and a resistor to form a voltage divider, which then feeds an amplifier stage. There are many ways you can solve this problem. Don't invest too heavily in just one at first. Step back from the problem and think of some different ways to do it, and then weigh the pros and cons of each.

More later, after you mull that over.

Cheers, Tom

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I love it!

Bob

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Just to make explicit what others did not...

"sci.electronics.homework" does not exist.

In these forums, people are very unwilling to do students' homework for them. Also, remember that your teacher may be here, too.

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Design consultancy is easy to obtain. It involves paying money though.

Graham

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