Voltage from rotation

Calmore

Jan 19, 2015
28
Joined
Jan 19, 2015
Messages
28
Think about how the coils/magnets are arranged in a motor. Not quite the same thing but designed to ensure maximum output for a given input.
 

wdariusw

Nov 10, 2014
149
Joined
Nov 10, 2014
Messages
149
Measured today magnet strenght. Gaussmeter shows 55mT , very low value I think....
 

wdariusw

Nov 10, 2014
149
Joined
Nov 10, 2014
Messages
149
Hi friends ! Working now with power management circuit for my generator (until waiting plastic holders for perfect coil-magnets positioning). I will use Texas Instrument bq25504 chip, low power atmega328P (or MSP430G2) and RF module. Now trying understant all bq25504 working principles. Want to ask - solar cell MPP point is about 80% open circuit voltage. Here i'm using electromagnetic generator, and can't find anything about maximum power point.. Piezo and TEG have IV like this :
article-2013sepetember-harvesting-energy-from-biological-fig5.jpg

So maximum power is at 50% Voc voltage. Maybe electromagnetic generator have the same characteristic? Of course, when i will make whole generator, then i will measure that curve by myself, but now i only want to know what is expected result. Thanks ! :)
 

MCombatti

Feb 13, 2015
6
Joined
Feb 13, 2015
Messages
6
Make a crystal cell to manage the circuit. They're cheap and you can make it any size, and with a small processing unit the crystal cell would last longer than the average human lifespan... or two... or three :)


[Mod Edit .... This is really bad info]
 
Last edited by a moderator:

Gryd3

Jun 25, 2014
4,098
Joined
Jun 25, 2014
Messages
4,098
Make a crystal cell to manage the circuit. They're cheap and you can make it any size, and with a small processing unit the crystal cell would last longer than the average human lifespan... or two... or three :)
Interesting... I saw one of these...
I don't believe it, but I still like seeing how creative trolls are becoming.
 

wdariusw

Nov 10, 2014
149
Joined
Nov 10, 2014
Messages
149
Make a crystal cell to manage the circuit. They're cheap and you can make it any size, and with a small processing unit the crystal cell would last longer than the average human lifespan... or two... or three :)
Can you post link about that crystal cells?
 

Gryd3

Jun 25, 2014
4,098
Joined
Jun 25, 2014
Messages
4,098
Can you post link about that crystal cells?
It's not worth looking up. Copper tube, some powder contents being melted over a hotplate inside the copper tube and a screw... Supposed to provide electricity for years.
You are welcome to look, but I smell a troll. It smells like anti-physics baking powder.
 

wdariusw

Nov 10, 2014
149
Joined
Nov 10, 2014
Messages
149
Need additional thought friends ! What is the best way to detect correct rotation of magnets ? I had idea to use reel switches, but i think i will be disappointed with that, because magnetic field is strong enough, and do position like this is almost impossible:

I do not have reels switches yet. But i think contacts will short about 1cm all around the magnets without any gap...
Another solution - hall effect sensor like this one http://www.ti.com/lit/wp/slyy058/slyy058.pdf . But it is active element, that consumes current...more than mcu...And here need 2 hall sensors as well... Or not ? Any ideas please !
 

Gryd3

Jun 25, 2014
4,098
Joined
Jun 25, 2014
Messages
4,098
Need additional thought friends ! What is the best way to detect correct rotation of magnets ? I had idea to use reel switches, but i think i will be disappointed with that, because magnetic field is strong enough, and do position like this is almost impossible:

I do not have reels switches yet. But i think contacts will short about 1cm all around the magnets without any gap...
Another solution - hall effect sensor like this one http://www.ti.com/lit/wp/slyy058/slyy058.pdf . But it is active element, that consumes current...more than mcu...And here need 2 hall sensors as well... Or not ? Any ideas please !
Can you elaborate on the 'correct' rotation you are trying to detect?
Are you after position or speed?
 

wdariusw

Nov 10, 2014
149
Joined
Nov 10, 2014
Messages
149
Sorry, my mistake...REED switch...Gryd3, here i only need to know or it is clockwise or anticlockwise.
 

Gryd3

Jun 25, 2014
4,098
Joined
Jun 25, 2014
Messages
4,098
Sorry, my mistake...REED switch...Gryd3, here i only need to know or it is clockwise or anticlockwise.
Reed switch, but only if there is enough of a magnetic gap between the magnets to let it turn off. How about a mechanical solution that only allows it to turn one way?
Similar to the rear sprocket on a bicycle?
 

wdariusw

Nov 10, 2014
149
Joined
Nov 10, 2014
Messages
149
Can't imagine simple mechanical solution, that fit here. Cyclist can pedal backwards, sometimes it is needed to do that..
 

wdariusw

Nov 10, 2014
149
Joined
Nov 10, 2014
Messages
149
Here i'm again ! :) So, little news from me. Have reed switches, and there are gap beween magnetic fields, so i think reed switches here will work as i want. Another new - made holder for coils.

Now positioning is perfect. 5 coils with 400 turns (without cores) . It generates about 700-800mV @1 rotation per second. Now making pcb with two options - with diode bridge, and with voltage multiplier. Will see how i will manage it...:)
 
Top