Roff
Well-Known Member
Below is a scheme that uses a preamp.I simulated it by Pspice. The waveform is not a standard AM wave at time domin!
SO I have done it wrong.
Please HELPPPPP.
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Below is a scheme that uses a preamp.I simulated it by Pspice. The waveform is not a standard AM wave at time domin!
SO I have done it wrong.
Please HELPPPPP.
Below is a scheme that uses a preamp.
I understand what you are trying to do. I'm sure you realize that, with a 12V supply, you will never get more than 12V p-p output.Ron,
I guess your current modifiction just amplifies the INPUT signal, not the carrier or DC offset (which creates the carrier or modulation index), Am I right? If so, Please keep in mind that I want to amplify the WHOLE signal (ones which goes into modulator input and consists of both DC offset and the input signal (that's why I tried to increase the gain of those 2 opamps by putting Rf and Rin to them. Make sense?
Sorry for my poor english language
I understand what you are trying to do. I'm sure you realize that, with a 12V supply, you will never get more than 12V p-p output.
Do you understand this?I'm sure you realize that, with a 12V supply, you will never get more than 12V p-p output.
Look at this. I didn't feel like making the schematic "pretty". This is what I simulated.why did I had ampelification when put an apamp at the output of the opmp?
Ron, Can I amplify the input signal by those 2 opamps which are connected to inputs of the modulator? I want t use a smaller input signal, Or I have to go for your second modification?
Look at this. I didn't feel like making the schematic "pretty". This is what I simulated.
I don't understand what your "power amplifier" input requirements are. Can you explain?
Car amplifiers are 25 Whats to 30 Whats which is only 2 Watts into an 8 ohm speaker. Some car amplifiers use two bridged amplifiers for 14 Watts into a 4 ohm speaker..
So whats the solution please?You don't have a 4 ohm speaker. You have a high impedance piezo transducer don't you? Then a car amplifier will not make it loud.
Here are results of simulation of the last circuit I posted, with the audio gain pot set at minimum, half scale, and full scale.
Your car amp probably won't have the bandwidth to handle your carrier frequency.