104Views7Replies

Author Options:

Rotational Charger? Answered

Any ideas how one could transform rotational movement into usable energy?  I want to attach a little radio device to a tire and have that device charge a little battery when the wheel rotates so that it can transmit information (i.e. rpm).  Was thinking of using a small Nordic radio and accelerometers to transmit data.  

Tags:charger

Comments

The forums are retiring in 2021 and are now closed for new topics and comments.
0
steveastrouk
steveastrouk

10 years ago

Put a magnet on the fixed part and a coil of wire on the rotating part, in line with the magnet.

0
lemonie
lemonie

Answer 10 years ago


Other way around?
You'd want your "stuff" on the stationary wouldn't you?

L

0
steveastrouk
steveastrouk

Answer 10 years ago

My way I think, he needs to power the rotating thing to broadcast back to the receiver ?

Steve

0
frollard
frollard

Answer 10 years ago

if he only needs RPM, he could use a hall effect or a coil and have the magnet on the rotor.

One could use the timing or analog voltage to calculate rpm/speed since faster= higher voltage.

0
steveastrouk
steveastrouk

Answer 10 years ago

True, I was reading this as on wheel sensing, you're right, its the other way round apparently.

0
lemonie
lemonie

Answer 10 years ago


You'd get a pulsed signal or otherwise-"frequencied", RPM wouln't be too hard from that?

I don't like the idea of "valuable-bits" strapped o a wheel with batteries.

L

0
orksecurity
orksecurity

10 years ago

The usual solution for bicycles is a magnet on the wheel and a reed switch which the magnet closes each time it goes past. Count closures per minute to get RPM. Cars, I believe, often measure this off the drive shaft rather than the wheel or hub.