Simple Squeeze Led Flashlight
Intro: Simple Squeeze Led Flashlight
Nearly 200 years ago Michael Faraday has discovered electromagnetic induction. A changing magnetic field produces an electric field in a coil. Today, there is a simple way to gain electricity from a relay and a strong magnet. I call this kinetic generator the RattleGen because, by pressing the lever of the relay quickly (the only moving part!) it makes a rattling noise. This electro generator is nearly solid state and produces enough energy to power a LED. Compared to 100 years of dyna flashlight based on a rotating generator, the RattleGen squeezer is nearly indestructible because of the few mechanical parts. This Ibble is part of an ongoing investigation for smallscale, batteryless energy harvesting.
27 Comments
Raqeeb123 6 years ago
Yonatan24 8 years ago
If you shake the flashlight really fast, Can't it exceed the maximum voltage of the capacitor?
Berto Aussems 8 years ago
The Maximum voltage of the capacitor is 16V. No way to exeed that voltage by fast squeezing. The only thing that happens is that the LED is going to light brighter. The voltage of the capacitor stays around 2.5 volt.
Wiramada 10 years ago
If I create this, I still must put a little battery (CMOS ~ I think it's better for recharged) and IC that can run a little tiny dynamo repeated around 1 minute (we can find that inside a cell phone)
Already try with Omron 12V but I just got 0.25V... Maybe must using Joule Thief to get enough power..?
~ 1 Vote for you :)
Berto Aussems 10 years ago
Thanks for voting for me! The most important part for gaining energy is the relay. Use a 24V relay with minimal 1200 ohm coil resistance. The magnet I use is a ringmagnet 10x6mm with a hole of 4mm, power N48 with a holding power of 3kg. A joule thief and a voltage step-up converter like the ZXSC380 pull's min.10 mA. I connected both; they use to much current and make's the LED flashing.
masynmachien 10 years ago
Thanks for this follow up on your RattleGen.
I really must try it in a workshop with kids one day.
For a workshop I would need about 20 relay I'm sure that will work, and scavenging that manny is not really practical.
So I would have to try an buy them cheap. The cheapest car relays are only around 1 euro and that is right into the ally of my kind of workshops, but I'm not sure if those would be suitable. Any recommendation on which ones to buy and where?
scarabdrowner 10 years ago
I would suggest adding a switch as well, to break the circuit when it's not needed, and to keep the capacitor charged up for quicker use the next time.
tomorrowsman 10 years ago
So out of my league, but would love to build one...could you provide a parts and tools list?
Berto Aussems 10 years ago
Good that you remember me at this point. I place the list in the Instructable. Because the few parts and tools needed, you get it here. Parts: 1 small relay 24V (watch if the contactlever is useful), 1 magnet 8mm diameter 4mm thick, 4 diode's 1N4148 or 1N914, 1 LED, 1 resistor 47 ohm, 1 capacitor 1000 microfarad 16V and a piece of printboard. Tools: Soldering iron, thin solderwire, a wirecutter, an iron saw, mounting wire. That's it. Some relay's you can only open with a saw. Others you can take off the transparant cover. Look for a relay with a minimum of 1200 windings; 1800 is better. Success with building one!
clichej1 10 years ago
You could make it bigger and mount the magnet on a spring so that it oscillates more for each push.
Berto Aussems 10 years ago
It is a step forward, when pushing results in more repetitious movements of the lever. Using mechanical oscillation or resonation to produce more pulses enhances de efficiency of the RattleGen. Clichej1, I like to tinker with spring's, this wonderfull objects. Maybe a new concept shows up. We keep in touch!
clichej1 10 years ago
Makes me remember some old ideas for converting omni-directional movements into electricity with magnets and coils like the concept of a shake flashlight but without the shaking. But i do not see how they could be useful on a bike since they would mostly rely on motion changes instead of direct wheel rotation.
Should experiment on those ideas when i get up to date in my current projects.
newbeatle 10 years ago
so nice..... maybe can be upgraded but the basic idea is so good !!!
dacarls 10 years ago
So- How can I build a bigger little generator say- by making a circle of your wonderful simple little generators into a magneto type generator? This could then be cranked by hand to spin the magnets inside a circle of wire coils- or hung up with a flywheel-pulley- string and weight to run your LEDs for- what 10 minutes at a time?
rainger 10 years ago
Dacarls - Great minds think alike! Check out http://deciwatt.org/
I've asked about being a tester, but they've moved forward and are expected to sell these in mid-2014. I might need to get one.
Still, I think you and I could each make a close resemblance right? That's what I'm planning to do! =)
alzie 10 years ago
There are 2 types -
pancake - stamped steel, cheap, higher losses.
hybrid - laminated core, ball bearings, more expensive, low losses.
Neither are terribly expensive.
These can be turned by your weight / pulley method.
Try the 24 V variety, as
theyll generate useful voltage with less rpm.
spikec 10 years ago
alcurb 10 years ago
I think I will make one. Here's my list of optimizations:
High efficiency ultra bright LED
Germanium signal diodes. They have an extremely low forward voltage drop so you can harvest more energy.
Low voltage Super cap.
Add a Joule Thief between the LED and the capacitor. Don't know if this will work or make it less efficient, but it is worth a try.
A small solar cell with adequate voltage to pre-charge the capacitor somewhat for a quicker start.
Berto Aussems 10 years ago
Ralphxyz 10 years ago