Fully disable PAS on Lectric?

[kylerlaird]

I want to disable PAS on my Lectric. I found a controller setting to make it throttle only, but PAS still has to be set to non-zero upon startup. Is there any way to make the controller disregard PAS altogether? (I'm trying to avoid getting another controller for it.)

 

[E-HP]

Does your controller always revert to 0 assist level on start up? Sometimes that is a setting (0 or recall last setting on start). You could just unplug the PAS sensor connector.

 

[kylerlaird]

Yes, it always starts at zero PAS and requires me to move it to another level before honoring the throttle input. I've already set it to throttle only so the cadence is ignored.

 

[amberwolf]

This question comes up now and then for various controllers. There hasn't been any built-in way to get around this for them yet.

You could build a single-pulse circuit with a 555 timer (powered from the system 5v or 12v) that upon power up gives a single button press to whatever button (+, etc) is used to advance the level to make the throttle work. It needs to be open-collector output so it doens't interfere with normal button operations, so if the button is activated by grounding it then you install a transistor driven by the output of the 555, with the emitter grounded and the collector wired to the button's signal trace.



FWIW, the reason controllers are often setup this way is for safety, so a problem with the throttle (physically stuck, broken ground, etc) won't just send the bike zooming off when it's turned on, since people may turn the bike on before they get on it. If they're already on it when they turn it on they may be more easily able to stop it in this event, but some people haven't even be able to hold onto the bike when this event happens and it goes zooming away. Indoors it usually goes up a wall and falls over, but outdoors if it's well-balanced it could go quite a ways before hitting someone or something or falling over.

 

[kylerlaird]

This question comes up now and then for various controllers. There hasn't been any built-in way to get around this for them yet.

Thank you for the explanation. I was thinking of adding a microcontroller anyway, so a button press was already on my mind but still feels suboptimal; it shouldn't be required.

I don't see any safety benefit in requiring a PAS button press. It'd be easy enough to require that the throttle be at idle before enabling the system. (I delivered a prototype last week and implemented an idle throttle check as part of the arming procedure.) It should be done anyway and there's little advantage to discovering a stuck throttle *after* hitting the "+" button.

Perhaps I'll just press the "+" button periodically when the throttle is at idle. That should work alright as long as the PAS level doesn't wrap.