I'm new here. Only not really. I built a very nice ebike with the help of smart folks here a few years ago. Rode it to work daily for almost a year. It failed and dumped continuous full-power to the rear wheel on a start from a traffic light. Rush hour. Front wheel came off the ground, no matter how much I stood up and leaned forward I couldn't bring it back down. Woke up in the street with a crowd of people staring down at me and ambulance attendees arriving. I recovered from the concussion in a couple days. At least I was wearing a helmet.
It was a prototype. I threw it together. It was my fault. It had no kill switch. Worse, it had a microprocessor in charge of everything with no emergency overrides. I'm a programmer, I should know better. Most likely the Cycle Analyst crashed while the system was at full throttle. It stayed at full throttle with no brains to impose limits. So I stopped riding it to work.
Now it's time to re-engineer the toy and make it work again. Safely. So I need some ideas for a kill switch or other similar safety mechanisms. Never trust a computer to impose limits when safety is at stake.
The machine:
* 26" moutain bike
* Crystalyte 408 rear wheel.
* 72-volt controller
* Cycle Analyst (early version)
* 72-volt battery comprised of 64 - A123 cells
Bike has a solid top/cruise speed of 40 mph. Okay, that's probably a bit crazy, but it's soooo much fun!
I'm thinking of simply adding a cutoff switch on the battery pack, stubbed out to the handlebars. But it would be nice if enough power remained to keep the Cycle Analyst functioning -- assuming it hasn't crashed. Yes, I know that's a bit messier. Every motorcycle I ever owned had a cutoff switch on the handlebars. Seems like a natural. (Or simply dumb not to have it.)
In addition it would be nice if the power cutoff extended to the last 1/8th inch of throttle travel ... just to be sure the harried rider doesn't have to think too much in an emergency.
If this has already been discussed (a dozen times perhaps) please point me in the right direction. It's been a while since I've been back here.
Mahalo!
Richard
It was a prototype. I threw it together. It was my fault. It had no kill switch. Worse, it had a microprocessor in charge of everything with no emergency overrides. I'm a programmer, I should know better. Most likely the Cycle Analyst crashed while the system was at full throttle. It stayed at full throttle with no brains to impose limits. So I stopped riding it to work.
Now it's time to re-engineer the toy and make it work again. Safely. So I need some ideas for a kill switch or other similar safety mechanisms. Never trust a computer to impose limits when safety is at stake.
The machine:
* 26" moutain bike
* Crystalyte 408 rear wheel.
* 72-volt controller
* Cycle Analyst (early version)
* 72-volt battery comprised of 64 - A123 cells
Bike has a solid top/cruise speed of 40 mph. Okay, that's probably a bit crazy, but it's soooo much fun!
I'm thinking of simply adding a cutoff switch on the battery pack, stubbed out to the handlebars. But it would be nice if enough power remained to keep the Cycle Analyst functioning -- assuming it hasn't crashed. Yes, I know that's a bit messier. Every motorcycle I ever owned had a cutoff switch on the handlebars. Seems like a natural. (Or simply dumb not to have it.)
In addition it would be nice if the power cutoff extended to the last 1/8th inch of throttle travel ... just to be sure the harried rider doesn't have to think too much in an emergency.
If this has already been discussed (a dozen times perhaps) please point me in the right direction. It's been a while since I've been back here.
Mahalo!
Richard