555 PWM of DC Motor with no load

Thread Starter


Joined Sep 8, 2008
Hey all,

How much difference is there for loaded and unloaded DC motors for a equivalent PWM driving circuit?

I was experimenting with PWM control of a cheap hobby DC motor via duty cycle modulation with the 555. I got the motor to change speeds but the difference was very subtle. I tried a few differenct RC combos for the 555 but still didn't notice too much of a difference?


Joined Dec 20, 2007
You forgot to attach your schematic so we do not know how you control the PWM of your 555.
If the PWM is done properly with two diodes then it goes from 5% so the motor is extremely slow or is stopped to 95% which is full speed.