07/20/2020 at 16:58 •
The impedance of the capacitors should be the same as the one of the coils in the motor at the desired frequency. The impedance is calculated as:With
Rcoil = Xc = 30Ohm
f = 50Hz
C = 106uF
As I use 2 capacitors in series, the best match is 2*220uF resulting in 110uF.
I measured the voltage at the both coils of the stepper with the oscilloscope and it showed that the value is okay (A picture of the wrong value is missing unfortunately, but believe me, it looks quite different ;-))
And the stepper is spinning with 60rpm.
07/20/2020 at 16:39 •
Fortunately this was an easy task: replace the 9,82kOhm resistor with 4,7kOhm. (I did not remove the original resistor, just put in a new one and moved the connection)
06/12/2020 at 13:38 •
While waiting for the PCBs, I worked on the clock source. As the PCB did not change from my prototype, I only had to create a small part in tinkercad.
Perfect ;-) - Now a little sanding and cleaning (and optionally some acetone-polishing (ABS print)) is missing.
With this design, the pulse will be 1/2 turn HIGH and 1/2 LOW. With one turn per second it will generate one falling edge for the CD4040 every second.
06/06/2020 at 12:15 •
- nothing more to say