I have the circuit below based on a simple 555 timer generating a PWM signal to dim an LED. The LED is lit but the brightness doesn't change as you would expect by adjusting the pot. Changing the potentiometer has no effect on the LED.
Another thing I noticed, I cannot see the PWM waveform on the scope it just looks like a stable voltage. This circuit works fine in real life on a breadboard. Is there something obvious I'm missing? Thanks.
I copied the schematic from this article: https://www.electronicshub.org/555-timer-pwm/
First of all… thank you for bringing this great circuit to my attention!!
So, In order to really see what was happening with this circuit I had to do a few things
I’ve used the mobile version as it is in my hand at the moment and I’ve constructed the circuit as per the schematic and made it a little bit neater
To give more resolution to the simulation, I changed the sim frequency to 2000hz with a timestep of 10us
Also, to really get some resolution in the scope I changed the 10nf cap to 1uf just to slow everything down
On the scope you can see how the pulse widths are changing as I have adjusted the pot :)
I shall check on PC version in the morning for a sanity check