you could probably have a voltage regulator and have it charge a relatively low capacity battery for longer use, but you would have to shake it for a long time before it would work, and that would be less cool. :) we all remember those "crank for 15 minutes get 30 seconds of useful light" flashlights.
Thanks for the vid. I'm trying to recreate something similar for a project. How many volts is required to power the flashlight for a minute and what input voltage would that require/ Is shaking the flash light for 30 seconds the same as inputing a 1.5 v battery? Also, will more wire turns result in greater output power? Thanks for any advice.
+Mint Thinny Typical white LEDs require 3 to 3.6 V to turn on. So a 1.5 V battery will not turn a white LED on. Shaking the flashlight for 30 s will store up energy, which can be used to turn on the LED. I don't know how much energy is produced in 30 s. It would depend on how fast you shake the flashlight. You could estimate the energy you produced by seeing how long the flashlight stayed on, assuming you knew the turn on voltage of the LED and the current the LED was drawing. For instance a Cree CLA1A-WKW-CXAYB153 white LED would probably be 3.6 V and 30 mA. So if you shook the flashlight for 30 s and it remained on for 5 minutes the energy you would have produced would be E = Pt = VIt = (3.6 V)(0.03 A)(300 s) = 32.4 J. Yes the more turns the more energy you would produce each time the magnet went through the coil.
Thanks! As an aside, can you explain how those crank flashlights work? Is a wire loop being rotated between magnets or is a totally different principle at work?
+Sean Jay It is the same principle, Faraday's law. Most likely a coil is turned relative to a magnet. Here is a video where I rotate a magnet inside a coil to produce a current in the coil. czcams.com/video/O5n6ubrbK5A/video.html
The voltage generated will scale with the number of turns and the total change in magnetic flux with respect to time inside your coil. So even with one turn and a small area you will get enough voltage if you can get enough change in magnetic flux. If your LED is not lighting, can you increase the number of turns?
Michael Melloch Thanks for the quick response and advice. I will do some experimenting with the number of turns. in the interim, is there an equation that related the number of turns to the voltage produced (I understand that there are more variables at play, but just trying to understand the mathematical relationship).
Tommy John Yes the equation is Faraday's law of electromagnetic induction, This video shows the experimental determination of Faraday's law, Electromagnetic Induction and Faraday's Law
I think the SMD LED is 0805 and not 0508! you can find some general info here: easycircuitlab.blogspot.se/2014/04/how-to-build-shake-tic-tac-led-torch.html The datasheet of the LED shouldtell you how much power it consumes usually it is in mA like 20 to 40 or so unless it is high power LED.
No, I would not rely on this one for a trip to the mountains. It is not very bright. It is more valuable as a demonstration of electromagnetic induction than as a flashlight.
so i want to turn the moon into a giant faraday flashlight, i want to bore directly through the moon's core and line that with the coil and drop magnets down the shaft to generate electricity and ship that electricity back with battery barges, anyone feel like tearing apart my idea?
+Blake Lewis Actually mechanical energy is being converted into electrical energy. When I shake the flashlight, I am applying a force through a distance, which is work. This mechanical work is being stored as energy in the capacitor in the flashlight.
robert Langdon brought me here
Thiago Lazarino same pinch
Inferno
So do I !!
Me too
Exactly
yesterday, I was watching the movie Inferno and decided to look for how this Faraday Lantern works. fantastic
Wonderfully clean straight ahead explanation. Thank you!!
Had the same one since 1998.still my go to light when batteries fail.
Always wondered how that flash light worked Thanks !!!!
Inferno…
Thank you for video and clear explanation.
New sub 👍
You are welcome!
Great explanation !
i don't why people haven't making new tech based on this thing,
it pretty simple and easy to understand
Oh hey, i've seen the concept of the shakelight being used in a 2016 indie horror game, tattletail!
you could probably have a voltage regulator and have it charge a relatively low capacity battery for longer use, but you would have to shake it for a long time before it would work, and that would be less cool. :) we all remember those "crank for 15 minutes get 30 seconds of useful light" flashlights.
Amazing guy
what are the ratings of the capacitor to hold the longest charge possible?
and do you use polarized(electrytic) capatitors or what type in particular?
I do not know. I did not build this flashlight, it was a gift, and I have not taken it apart.
How make this please. Any tutorial? Thank you
Thanks for the vid. I'm trying to recreate something similar for a project. How many volts is required to power the flashlight for a minute and what input voltage would that require/ Is shaking the flash light for 30 seconds the same as inputing a 1.5 v battery? Also, will more wire turns result in greater output power? Thanks for any advice.
+Mint Thinny Typical white LEDs require 3 to 3.6 V to turn on. So a 1.5 V battery will not turn a white LED on. Shaking the flashlight for 30 s will store up energy, which can be used to turn on the LED. I don't know how much energy is produced in 30 s. It would depend on how fast you shake the flashlight. You could estimate the energy you produced by seeing how long the flashlight stayed on, assuming you knew the turn on voltage of the LED and the current the LED was drawing. For instance a Cree CLA1A-WKW-CXAYB153 white LED would probably be 3.6 V and 30 mA. So if you shook the flashlight for 30 s and it remained on for 5 minutes the energy you would have produced would be E = Pt = VIt = (3.6 V)(0.03 A)(300 s) = 32.4 J. Yes the more turns the more energy you would produce each time the magnet went through the coil.
Thanks for your reply. Your answer is a great help.
Would this work in reverse? Like have a piece of copper going through a magnet with a hole in it?
Yes there are a number of ways you can cause the changing magnetic flux--a linear movement of the magnet or coil, rotating the magnet or coil, etc.
Ah, the diode bridge. I should have thought a little before I looked the answer up. Thank you.
good work
Thanks!
thats so cool!11
It is, thanks!
what is the most simplist design of a capacitor and a diode in the case of replecating a farraday flashlight like this
I don't know if there is a way to make it simpler than the circuit I show in this video.
could you explain how the capacitor is designed? thanks alot this is very helpful
easycircuitlab.blogspot.se/2014/04/how-to-build-shake-tic-tac-led-torch.html
igrewold Thanks for posting this.
How can you increase the power generated per pass?
Probably more windings and stronger magnets
Cool.
Damn this is cool. Exam on Faraday's law and inductance in about 3 hours... thanks for the distraction :D
+Sean Jay You are welcome and good luck on your exam!
Thanks!
As an aside, can you explain how those crank flashlights work? Is a wire loop being rotated between magnets or is a totally different principle at work?
+Sean Jay It is the same principle, Faraday's law. Most likely a coil is turned relative to a magnet. Here is a video where I rotate a magnet inside a coil to produce a current in the coil.
czcams.com/video/O5n6ubrbK5A/video.html
Is that a Full-wave rectifier?
+Azfar McHaziq Yes
Thats super cool but do you know where and how i could buy/get one?
www.amazon.com/Shake-Light-40-Rechargeable-Flashlight/dp/B00HS5M706/ref=sr_1_5?crid=1NC4X6GYLFCQH&keywords=faraday+flashlight&qid=1676144259&sprefix=faraday+flash%2Caps%2C144&sr=8-5
its like magic
Science is!
How many turns are their
I do not know. It appears to be fine wire so probably a few thousand.
Where to buy it?
www.amazon.com/EcoCentricNow-LLC-Shake-Rechargeable-Flashlight/dp/B00HS5M706/ref=sr_1_2?crid=2BHRB10P7PG7F&keywords=faraday+flashlight&qid=1556997772&s=hi&sprefix=faraday+las%2Cdigital-text%2C179&sr=1-2
What is the capacitor details
I do not know. I would have to take the flashlight apart.
Please some tell the value of capacitor
What about torches for Monday, Tuesday, Wednesday and Thursday ??
2022 Robert Langdon also brought me here
Great video. Do you know how small you can make a Faraday coil and still get a current? I am trying to light an 0508 SMD LED with a very small coil.
The voltage generated will scale with the number of turns and the total change in magnetic flux with respect to time inside your coil. So even with one turn and a small area you will get enough voltage if you can get enough change in magnetic flux. If your LED is not lighting, can you increase the number of turns?
Michael Melloch Thanks for the quick response and advice. I will do some experimenting with the number of turns. in the interim, is there an equation that related the number of turns to the voltage produced (I understand that there are more variables at play, but just trying to understand the mathematical relationship).
Tommy John Yes the equation is Faraday's law of electromagnetic induction, This video shows the experimental determination of Faraday's law, Electromagnetic Induction and Faraday's Law
I think the SMD LED is 0805 and not 0508! you can find some general info here:
easycircuitlab.blogspot.se/2014/04/how-to-build-shake-tic-tac-led-torch.html
The datasheet of the LED shouldtell you how much power it consumes usually it is in mA like 20 to 40 or so unless it is high power LED.
I knew it had a rectification circuit
Is this flashlight effective?
It is not very bright. But I have had it for a long time (8 years?) so I would imagine the LEDs are brighter in the ones you could buy today.
So would you bring it with you on a journey to the mountains?
Late reply, but I recommend crank powered much more than this
No, I would not rely on this one for a trip to the mountains. It is not very bright. It is more valuable as a demonstration of electromagnetic induction than as a flashlight.
Oh ok thanks
Reading inferno brought me here hahaha
it has 3 button batteries, one of the best fakes ever
Inferno brought me here
so i want to turn the moon into a giant faraday flashlight, i want to bore directly through the moon's core and line that with the coil and drop magnets down the shaft to generate electricity and ship that electricity back with battery barges, anyone feel like tearing apart my idea?
THE GUMMY FLASHLIGHT IS REAL
YESSSSSSSSSSSSSSSSSss
Surisped nobodys here becomes of rooms
Free energy
+Blake Lewis Actually mechanical energy is being converted into electrical energy. When I shake the flashlight, I am applying a force through a distance, which is work. This mechanical work is being stored as energy in the capacitor in the flashlight.
Understood
Anybody else here have this for an assignment? 🙋♂
Muth wali flashlight
so many mouth sounds
ew