EEVblog® Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: CM800 on November 16, 2016, 10:35:06 pm
-
Hi All,
I was wondering if you guys would give a quick look at this, see if there is any obvious faults?
(http://puu.sh/skCuz/e0dcff2846.png)
(http://puu.sh/skCvj/21803c01d3.png)
Also, is it possible you could put 5V on the output resistor rather then 12V, I wasn't sure if it should be going below VCC, but since my logic on the board this module would go to is 5V, I'd rather this be too.
I planned for this to output PWM @ 20kHz to drive small a little HV flyback transformer to give an HV arc output (Plasma Speaker)
-
Between pin 2 & 3 need feedback resistor and pin 1 need 0V
5V is ok depends what MOSFET you have
-
Between pin 2 & 3 need feedback resistor and pin 1 need 0V
5V is ok depends what MOSFET you have
here is the original circuit I was working off
(http://geekcircuits.com/wp-content/uploads/2010/07/Tl494-with-filtered-FB2.png)
I'm forgoing the feedback in this case.
It may work, but the audio quality may as well be horrible. I suggest some higher performance modulator designed specifically for hifi class D applications, such as these IR digital amp ASICs or TI ones (even come with power stage or a real gate driver that can drive massive MOSFETs).
I agree and somewhat expect that, though to be honest it's going into a transformer and the audio will come from the arc expanding and contracting, like so:
https://www.youtube.com/watch?v=cEeWtBAE5LY (https://www.youtube.com/watch?v=cEeWtBAE5LY)
I couldn't find any good modulators without the power stage. (I want to be able to put mains DC in)
-
Hi All,
I was wondering if you guys would give a quick look at this, see if there is any obvious faults?
(http://puu.sh/skCuz/e0dcff2846.png)
(http://puu.sh/skCvj/21803c01d3.png)
Also, is it possible you could put 5V on the output resistor rather then 12V, I wasn't sure if it should be going below VCC, but since my logic on the board this module would go to is 5V, I'd rather this be too.
I planned for this to output PWM @ 20kHz to drive small a little HV flyback transformer to give an HV arc output (Plasma Speaker)
This has been discussed over at diyaudio,
http://www.diyaudio.com/forums/class-d/148287-doing-class-d-amp-project-using-tl494.html (http://www.diyaudio.com/forums/class-d/148287-doing-class-d-amp-project-using-tl494.html)
TL494 is a bad choice, for example it uses sawtooth instead of a triangle wave. A simple class D amplifier with quite good performance can be built around just a fast comparator. Do some research on the UcD concept. It's a phase shift oscillator that amplifies audio and damps output filter resonance to flat response regardless of speaker impedance in the process...