I am new to oscilloscopes
I just bought a Hantek DSO2D15 to try and resolve an issue with a laser driver board. The laser driver is controlled via a 24V PWM fan control supply from an Ender 3 Pro. My first step was looking at the PWM supply.
The PWM seem to be working correctly, in that, adjusting the fan speed changes the size of the pulse.
The problem is between the pulses instead of going to 0V a sinusoidal shape wave of primarily negative voltage occurs. See Photo 1.
What is causing this?
If I connect the oscilloscope in reverse I actually get the correct shape with no sinusoidal shape wave between pulses. See Photo 2.
Why the difference when connected in reverse?
Any help will be appreciated
Alan Vernon
Why the difference when connected in reverse?
Any help will be appreciated
Alan Vernon