Movement detection switch wanted for bike (electrical)

[snorri]

[QUOTE 3928503, member: 9609"] the on off mechanism is inside the cycle computer [/QUOTE]
I can't imagine which type of cycle computer would include an on-off mechanism.

 

[snorri]

[QUOTE 3928556, member: 9609"]the one I have seems to sense the wheel moving and switches the timer on, then when the wheel stops rotating for a few seconds it switches the timer to off - very reliable. but it is all done deep within the circuit board and I have no idea how to utilise it.[/QUOTE]
What you describe is not a mechanism but a bit of fairly simple electronic circuitry, however few amateurs would have the expertise to locate and isolate that circuitry from within a cycle computer, it would make no sense to attempt to do such a thing.

 

[Fnaar]

I'll ask Miss Goodbody how her "pleasure bike" works. She might be able to help. I think the Vicar rigged it up for her.

 

[LonesomeWanderer]

What you're describing is a basic monostable circuit or 'missing pulse detector' which is relatively easy to put together with a 555 timer. It won't be anywhere near as compact as an off-the-shelf cycle computer though.....

 

[classic33]

On a cycle computer isn't the switch mounted on the forks, with what the switch is operating on the handlebars?

 

[vernon]

What you're describing is a basic monostable circuit or 'missing pulse detector' which is relatively easy to put together with a 555 timer. It won't be anywhere near as compact as an off-the-shelf cycle computer though.....

He doesn't want a cycle computer.

As I read it, I might be wrong here, User9609 wants a switch/relay that latches on from the first pulse from a cyclecomputer sensing unit and uses the relay to switch on/supply current to an unspecified device at 0.5A and 5V.

As Adrian suggested a simpler solution might be to buy a hub dynamo. The output can be transformed into the voltage and current needed by something like an e-werk device. No trickery anr fiddling needed. The current stops once the wheel stops rotating.

 

[LonesomeWanderer]

He doesn't want a cycle computer.

As I read it, I might be wrong here, User9609 wants a switch/relay that latches on from the first pulse from a cyclecomputer sensing unit and uses the relay to switch on/supply current to an unspecified device at 0.5A and 5V.

As Adrian suggested a simpler solution might be to buy a hub dynamo. The output can be transformed into the voltage and current needed by something like an e-werk device. No trickery anr fiddling needed. The current stops once the wheel stops rotating.

Sorry, I was just mentioning the computer for size-comparison. The main thing he needs is a monostable circuit of some kind to take the pulse from the reed switch/wheel sensor and keep the circuit open (or a dynamo).

 

[mybike]

OK, a purely mechanical idea here. We used to use slugged relays in ancient days in the GPO. They'd be slow to operated or slow to release due to a chunk of metal adjacent to the coil. You could do something similar with a reed relay, tripped by the rotating magnet on the wheel, possibly a magnet at a distance on the fork that would just hold the relay on for a period after the magnet passed. It would take a certain amount of 'playing' to get the distance right.

 

[classic33]

Any use?

http://www.instructables.com/id/Magnetic-speed-sensor/
http://www.instructables.com/id/rare-earth-magnet-magnetic-induction-loop-trickste/
http://www.instructables.com/id/DIY-contactless-magnetic-bike-rim-dynamo/