Yes, the TV will show the funny effects, AM radio will not work at all, FM radio will produce HISS, and the airplane pilot will be not able to communicate undistorted with the airport for landing...
airplane pilot will be not able to communicate undistorted with the airport for landing...
Hahahaha... Ladies and Gentleman..HISSSSSSS.. This is your cap...HISSSSs.. Thank you for...HISSSSSS..
You know what. I'm done amp wise and I have time to screw around. So no harm done even If i fail at attempting this. I want to take a proper shot in terms of designing a proper reference waveform.
What is a good Op-amp to use? I used TL072 before for creating the triangular carrier and sadly my triangular waveform looked like a sine-wave and i was told to abandon my idea and use PWM IC's (like the TL494).
Is my logic correct?
http://img403.imageshack.us/img403/6784/crap10.png
What is a good Op-amp to use? I used TL072 before for creating the triangular carrier and sadly my triangular waveform looked like a sine-wave and i was told to abandon my idea and use PWM IC's (like the TL494).
Is my logic correct?
http://img403.imageshack.us/img403/6784/crap10.png
Generally, the logic is correct. If you do not plan to use any feedback, then you can use any comparator. If the FB needed, then it is needed to use the fast comparator, LT1016 for example, or your old LM361...
Generally, the logic is correct. If you do not plan to use any feedback, then you can use any comparator. If the FB needed, then it is needed to use the fast comparator, LT1016 for example, or your old LM361...
and op-amp?
Ok more questions are popping up for me now.
By feeding back the error amplifier output, how does it make this amplifier circuit a closed Loop system?
The feedback in closed loop systems are taken from the switching (pre-filter) or output filter (post-filter).
Only the error produced within the TL494 is compensated. However any errors further onwards are not compensated.
By feeding back the error amplifier output, how does it make this amplifier circuit a closed Loop system?
The feedback in closed loop systems are taken from the switching (pre-filter) or output filter (post-filter).
Only the error produced within the TL494 is compensated. However any errors further onwards are not compensated.
Look at that crappy drawing I did with MSpaint as to my Logic. I am asking what's a good Op-amp to use, that is also cheap to buy. Otherwise I will see if I can get some samples off texas Instruments.
Yes I did use TL072 for both Op-amp and comparator to produce Triangular Waveform last time.
But this time I would like to Use a proper High speed comparator and also a good op-amp (High Slew Rate and Gain Bandwidth Product).
Yes, the errors of the output stage and power supply fluctuations are not compensated in this project...
I was thinking of TLV2302. It's a handy IC that I can get a free sample of. It has 1 Op-amp and 1 comparator already in it. Or TL2304 which has 2 op-amps and 2 comparators.
Making it efficient to do triangular wave carrier and PWM comparator all in One IC.
Just it's response time and other factors are not great in terms of a class D amplifier, hence my hesitation to go out and order some free samples of it.
Making it efficient to do triangular wave carrier and PWM comparator all in One IC.
Just it's response time and other factors are not great in terms of a class D amplifier, hence my hesitation to go out and order some free samples of it.
By increasing the gain of the error amplifier. I increase the sensitivity of the error amplifier.
So for a gain of 10, my sensitivity is 0.3 (Since my Sawtooth is between 0-3V). Whereas for a gain of 20, my sensitivity is 0.15?
So clipping occurs much faster at a gain of 20, then with a gain of 10?
So loudness will increase but the disadvantage is clipping will occur faster and give you distorted music as a result.
Although in my case I'd say 10 is a little too much.. Something just a little bit less should do it, because at a gain of 10, the music (Some music not all) causes clipping just before the volume pot is cranked to max. And I mean just a little bit more turn and I have cranked it to max. That's how close it is to max when clipping occurs.
So for a gain of 10, my sensitivity is 0.3 (Since my Sawtooth is between 0-3V). Whereas for a gain of 20, my sensitivity is 0.15?
So clipping occurs much faster at a gain of 20, then with a gain of 10?
So loudness will increase but the disadvantage is clipping will occur faster and give you distorted music as a result.
Although in my case I'd say 10 is a little too much.. Something just a little bit less should do it, because at a gain of 10, the music (Some music not all) causes clipping just before the volume pot is cranked to max. And I mean just a little bit more turn and I have cranked it to max. That's how close it is to max when clipping occurs.
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Actually I've only heard the clipping, not seen it in a scope. When clipping does occur and I scope the output, instead of a proper sine wave, I should expect a chopped sine wave right?
Because so far all I've seen out of the output is a sine wave (normal one) that becomes disbalanced once modulation occurs.
Because so far all I've seen out of the output is a sine wave (normal one) that becomes disbalanced once modulation occurs.
Please, do not mixup the residual sinewave (200Khz) and the input music wave... Simply put the 1Khz sine wave to the input of your amp and look with the scope at the output with max volume...
I think, at max volume the amp is clipping, so there is nothing funny, because clipped sine wave contains a lot of harmonics too
Can you post some FFT pictures here? Just interesting...
I think, at max volume the amp is clipping, so there is nothing funny, because clipped sine wave contains a lot of harmonics too
Can you post some FFT pictures here? Just interesting...
Of course, once I understand how to operate this relic of a harmonic analyzer they have provided me with.
Yes, the gain seems correctly...
The gain of the TL494 error amp is 10, and the gain of the end stage is approx Vout/Vtriangle. So your Vout is 20V, Vtriangle (sawtooth) is 3-4V, so end stage gain is 20/4 = 5, and overall gain is approx 10*5 = 50...
Also, the volume pot sets the gain too, so your result gain (30 approx, as you said) can be affected by this.
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