hissingnoise
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Modifying the Electronic Controls of a Pedal-assist Bicycle. . .
A friend has been attempting some modification of one of these 'battery-powered' bikes!
He got it as a mobile exercise 'thing' and now finds that he is often miles from home by the time his exercise regimen has lost its dubious appeal,
and he figured that by bypassing the magnetic sensor on the pedal assembly, he could switch between 'pedal-assist' and powered biking at will thus
motoring home when he'd had enough of leg-waving.
So, thinking the black box beneath the battery was some kind of electro-mechanical regulator, he exposed its innards, only to be confronted by a
fairly complex piece of circuitry of a kind he knows nothing about.
He asked me to find some info that might help with his 'project', but so far I've drawn a blank. . .
Does anyone here know anything about these contraptions?
Oh, and as caveat I should add that what he is attempting is technically illegal as these bikes are normally exempt from regulations.
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not_important
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Tough question to answer. A little research showed that there are two main classes of sensors, one responds to speed/rotation rate only while the
other senses applied torque. Some models also monitor the selected gear ratio. Some include the motor controller logic as well, being based around a
device like the Freescale 56F8xxx production with multi-channel PWM for driving a brushless polyphase AC motor and multi channel ADC.
My suggestion is that your friend do a better job planning their routes so they do not get so far from home as to make the return pedaling all that
bothersome.
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hissingnoise
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Thanks n.i.---route-planning was my suggestion, too, but he brings a camera with him and when he spots a possible shot in the distance route-planning
goes out the window. . .
I'm using better search-terms now (info dribbling in) but as you say; it ain't easy.
Hooking sensor and magnets to a small, battery-driven motor with a switch could be a last recourse, but bypassing the sensor would still be the ideal.
. .
[edit]
The other thing that occurred to me was that he could possibly, by switching, bypass the controller altogether and power the motor straight from the
battery, but when the motor would strain uphill he'd need to dismount and walk.
And that's assuming that full battery-current/voltage wouldn't overload the motor.
[Edited on 19-11-2009 by hissingnoise]
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densest
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Mood: recovering
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A detailed photograph (tiff/pnm only, jpeg would be unusable because of lost detail) of the controller board and sensor assembly
might let us reverse engineer enough to give suggestions. The pictures would only be useful if all the text on the chips was readable. Repeat after
me, no compression, no jpegs...
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