Hi,
I followed the YouTube 555 PWM. Simple Circuits :

to do on breadboard, I got wave some time, but can not adjust the output, the led‘s brightness doesn't change when turning the pot, and also can't get the result repeatedly?
what should do now?
Thanks
Adam

 

Check for a likely wiring error.

 

Check for a likely wiring error.

Thanks, I'll.
Can the pot control the frequency of PWM or the capacitor do? please ref.:
https://www.instructables.com/id/555-Timer-Universal-PWM-Controller/
Best

 

In that circuit the pot controls the duty cycle and the cap value determines the frequency.

 

Did you notice the connections from pin 2 to 6 (blue) and 4 to 8 (red) ?
Keith

 

In that circuit the pot controls the duty cycle and the cap value determines the frequency.

Thanks.
So, the possible reason the pot doesn't effect may be wiring error? also I saw some body used Electrolytic capacitor and some used Ceramic capacitors, big difference?
Best.

 

Did you notice the connections from pin 2 to 6 (blue) and 4 to 8 (red) ?
Keith

Thanks,
Yes, I did it. please see the picture of the wave attached.

 

Did you notice the connections from pin 2 to 6 (blue) and 4 to 8 (red) ?
Keith

Thanks.
does the Electrolytic capacitor and Ceramic capacitors matter?
Best

 

does the Electrolytic capacitor and Ceramic capacitors matter?

you're up and running. Make the component changes you wish note down your results of the waveform and have fun.

 

does the Electrolytic capacitor and Ceramic capacitors matter?

If you are using an electrolytic cap then the polarity must be correct. Polarity doesn't matter for a ceramic cap.
If the pot doesn't vary the brightness, make sure you have the polarity of the diodes correct.