I made a EL wire persistence-of-vision circuit for my bike, it's supposed to show Pacman on my bike wheel using yellow EL wire
I have everything perfect, triac to switch on and off the EL wire, hall-effect sensor to sense my wheel's speed, everything does work, I can run test code that turns on the EL wire when the magnet is N.
I have one problem... When I run my Pacman pattern code, it doesn't seem to show up as expected... At low speeds, it seems like it works, but at higher speeds, it just doesn't seem to show the Pacman shape. I'm starting to suspect that maybe EL wire is unsuitable for this application due to a slow reaction time. Can somebody confirm this?
How fast can you switch on and off a EL wire? Does it have to do with the fact that it uses AC? Does it have to do with the properties of a TRIAC instead?
Where are you switching the EL wire supply, is it on the input end to the power supply or the output end?
However if it is working at low speeds then something isn't up to speed but it could be the hall effect sensor, what does the data sheet say?
I don't suspect the hall effect sensor since SpokePOV used the same thing, but I didn't realize it could be my problem, thanks for pointing that out.
I just checked, the sensor has a maximum switching frequency of 10 KHz, that should be plenty. I'm not sure about how other parameters might affect that
If it's lag that causes the issue, I should still see my Pacman pattern, just offset slightly, right?
If it's lag that causes the issue, I should still see my Pacman pattern, just offset slightly, right?
No it would not be a lag if the hall can't switch that fast. It could be the on off ratio of the hall. It is ok saying 10 KHz but that assumes a field for half this time. What is the pulse width you are getting from it? Try putting two magnets side by side to see if that improves the top speed.
You could try just free running it to see if you are switching fast enough.