- Joined Dec 27, 2019
Hey, I am also building this circuit, but it in my circuit, Hex inverter is not inverting my PWM signal.Hi everyone,
This is my first time posting, so I hope I didn't post in the wrong section.
My friend and I have been working on a university project, where we simply choose what we want to build, and present a valid schematic from the internet to our assistants.
I found a circuit from the youtuber GreatScott, and ordered all the parts (I've put it in the attachment). We have changed the circuit, by adding 220nF capacitors at the inputs of the comparator, in order to eliminate the DC offset of the triangle wave and the amplified input wave. We have also put a potentiometer at the output of the LM386 as a voltage divider, in order to have a primitive volume control.
We connected all the components on breadboards, and put an 8ohm speaker at the output. The circuit worked fine when we used a function generator as the input, which was set to a 1kHz sine wave with around 500mV peak to peak. However, once we connected the input to one channel of an audio jack, which was connected to a PC (and a smartphone later on), as we slowly raised the volume, we could hear the sound, fairly distorted, for maybe half a second. Afterwards the 15V supply voltage from our lab bench power supply went into CC mode at 300mA output and the voltage dropped to around 5V. Increasing the current definetly doesn't help.
Once we lower the volume, everything goes back to normal with no output at the speaker, and as soon as we raise the volume, the same thing happens.
I have run out of ideas as to what could be the problem, so I would love to hear any advice.
I'm sorry for bothering, and I thank everyone in advance!
Moderator edit; New thread created from old thread.