Selsyns and Amplidynes

Subject is "pedal by wire".
The idea has been around for a long time, retro EVen...
http://en.wikipedia.org/wiki/Selsyn

...but it's never made prime time for pedal machines... yet...

Dr. Andreas Fuchs has been promoting the idea for pedal bikes for a decade. From here:
http://www.futurebike.ch/images/1_wsj_shorter_1.pdf

"The idea of the electronic bike, winner of the Transport category of The Wall Street Journal Europe Innovation awards, was entered by Dr. Andreas Fuchs. Dr. Fuchs, who works at the University of Applied Science in Berne, is also chief executive officer of Autork Ltd., a company that produces hardware and software for chainless humanpowered
vehicles. "The innovation consists of a pedaled generator that transforms human power into
electric power," Dr. Fuchs explains."

and

"Like the bike builders at the University of Applied Science in Berne, design consultants
Ecomotion Bike and the ExtraEnergy society in Germany, he is working to replace the
bike chain with technology that would transfer kinetic energy between the pedals and
the wheels using electronics. The pedals would drive a generator that ultimately powers
an electric motor."

(That futurebike.ch site is kinda fun btw by the Swiss HPV association)

But no news from any of these folks in several years now. Anyone know yet if the latest electrics/electronics might have made this approach any more viable yet?

The tech is at least able to swivel a gun turret, so I keep thinking that one day it'd be nice to chuck the mechanical chain/gears that couple pedal to wheel? Are selsyns too lossy or something? Some inherent flaw with the approach?
Tks
LOck

>>>Anyone know yet if the latest electrics/electronics might have made this approach any more viable yet?<<<

Could be...


http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=3423&hilit=


(edit to update image)

Thanks for that TD. Yah, sorta... Guess I was thinking more like parallel rather than series... So here Peter is basically pedaling a generator as battery charger, seems like. Easier to implement I guess. Haven't read on any pros/cons series versus parallel. Pedaling at stops would be amusing. Bit OT but I had a thought once to put a compound bow under a trike where pedaling at a stop would draw the bow. Never figured out the linkage though, for the switch from drawing to controlled release... Mechanical capacitor perhaps you can say. More sophisticated than a rubber band at least

Lkg fwd. for more updates from Peters efforts. Whether that first pass at an efficiency calc at 50% was real or might be improved on.

tks again
L

The efficiency of Peter's setup is not great, but the basic idea works. With high-tech parts, the efficiency could be much better, but I doubt it would ever be as good as a chain.

The beauty of it is you can pedal with the same cadence regardless of bike speed. On a faster e-bike, you usually run out of gearing at the top end. This would solve that problem, allowing human input at any speed.

If you used a drive chain and a generator with a differential between them, you could do something like a Toyota Prius. This way part of your pedal effort goes directly through the chain and has lower losses.

I've been thinking about serial setup for a while. Obviously there is a significant efficiency penalty to this configuration. One thing to remember though that iron losses in drive motor are invariant of the setup so the serial configuration additional loss is 2 x copper loss + 1 x iron loss + electronics loss.

What I do like about the setup is that in a trike configuration you can pedal continuously even if you stopped at the traffic light. Transmission ratio can be maintained automatically and continuously for minimal fatigue. And it really simplifies weatherproofing the hybrid velomobile body.

Thinking about the electronic suspension aspect of that bike - one can use mechanical load spring with electrical damper. Then damper-generated energy can be pumped back into the battery good for maybe another 1% range

I totally missed this thread earlier. Good to see my picture in a thread

I'm hoping someone makes good progress on a BMS/charger solution on this forum. The lead acid batteries are fine with hooking a generator through a diode to them, but I suspect lithium ion batteries will get upset. I thought about attaching an inverter to the generator output and then powering a battery charger, but I think the charger might get angry about the batteries being discharged at the same time as they are being charged. Any thoughts?

My goal with the serial hybrid was to make something that works and is easy to build. Currently it's ridiculously easy to build, easier than a regular ebike (if you are building from the ground up). Despite the inefficiency, it would be good for handicapped people and crazy looking Burning Man bikes.

Additionally I have used it to run appliances through an inverter when the power was out.

It actually should work fine with lithiums with a simple rectifier bridge as long as you do not exceed maximum charge current of the pack and the maximum pack voltage. You can monitor both with CA or wattmeter. BMS is desirable but there is pretty large safe area with partially discharged battery where super accurate individual cell monitoring is not absolutely needed. The critical area is really around fully discharged and fully charged states. I am working on a conventional parallel setup with regen that currently is not using BMS for regen charging of lithium packs (it may in the future). The only thing I have is a per-cell LVC plus CA for total pack voltage/current monitoring.

Sometime in the future though I'd like to build a dual seat (side by side) trike with serial electric transmission.