A motion sensor switch for a light on a wheel?

[pretzelz]

Hi everyone,

I have a little keyring LED torch with a push on and off switch. I have taken the case off and removed the switch. Now I want to replace it with an appropriate motion sensor switch that will detect when the torch is experiencing movement, and switch it on.

My aim is to mount this small flat torch on a bicycle wheel. So essentially I want it to turn itself on when the wheel is rotated and create a spiral of light.

I am based in the UK, and have looked on various websites, including Maplins, for an appropriate type of motion sensor switch that I can solder on in the place of the old switch. However I need your help, because most of the switches I come across are Tilt switches, which might work fine as the wheel is spinning, but when the wheel is stopped, if it stops at a certain angle, the tilt switch sensor may remain on.

Perhaps you could point me in the direction of the right type of switch and a source for it? Other than say, ripping one out of this similar item:

http://cgi.ebay.co.uk/2-Car-Wheel-T...tyres_trims_Valve_Caps_ET&hash=item3a5c3e15df

-By the way, I have my own DIY reasons for wanting to do this myself rather than just buy a valve light cap as seen in the above link.

Many thanks!

 

[Taylortwocities]

Troll alarm, maybe?

Good grief


Edit:

on second thoughts..


buy an iPhone and develop an APP that works with the phones movement sensor.
Build a bluetooth interface for your torch,
strap your iPhone to the wheel

Voila! Broken iPhone - fantastic

I'm going to run a hot bath and slash my wrists.

 

[ColJack]

i'm thinking spring, small weight and a microswitch..

alternatively, 2 mercury switches linked by a wire and wired in series, on opposite sides of the wheel..
the centrifugal force of the wheel spinning will force the mercury outwards and make both switchs, but when stopped, regardless of the angle only 1 will be on..

 

[pretzelz]

Thanks, although that sounds a little complicated.

I was really hoping just to find out the name of the type of motion sensor they might use in that cheap LED value cap so I can buy it and solder it to my keyring LED torch. If we sell tilt switches etc for less than a pound, there must be surely a variation that would work.

 

[viewer]

What about a pedometer? They are basically a swinging arm plus electronics in a box. You should be able to take a feed from the arm sensor through a transistor to a relay for the lights

 

[TicklyT]

tilt switch controlling something like a 555 timer, set up to switch off if the tilt switch stops toggling?

pendulum triggering hall effect sensor?

'Slipping clutch' on hub operating a microswitch?

Dynohub wheel?

Centrifugal switch?

 

[1john]

three or four tilt switches arranged in a spoke formation with connections inwards and wired in series? I presume they are mercury ones that you get? that way the pull from the wheel spinning would activate them all and when stationary there has got to be one that breaks the circuit that will end up upside down?

 

[holmslaw]

..

 

[ericmark]

Many single phase motors have built in a centrifugal switch. As to home made simple insulator on spoke with spring out of a pen etc.
There are kids toys which have batteries switch and lights already built in. My grand children spin them on string around their heads.
Spinning tops also often have this arrangement and likely a tad cheaper than Iphone

 

[timtheenchanter]

spinning tops/yo yos with flashing lights in them, butcher it, there you go centrifugal spring switch.

I need to ask, what are the reasons for not going for a ready made approach??

and just one more point, unbless the light source moves in and out from the center of the wheel, you will get just a circle of light, nor a spiral if that is the effect you were after.

watch the overall weigh as well, could afftect your wheel balance quite a bit...