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Function:

It's a wheel spoke mountable safety light for your bike that doesn't need batteries. Ever. It also has smart on/off function. Light turns on when you start moving and turns of about 5 seconds after you stop moving.


Features:

No batteries needed. Never end up in dark with your bike.

Smart on/off function. Light turns on when you start moving and turns of about 5 seconds after you stop moving.

Custom inscription/logo/colors.


Parts list

(1) Neodymium magnet 2x

Dimensions: Diameter from 10 to 12mm, thickness from 4 to 10mm.

Source: Old HDD, ebay

(2) Spoke mount left - 3d printed part

Source: Print it yourself. All 3D models freely available at thingiverse:

http://www.thingiverse.com/thing:907511 or buy here:

http://hotmess3d.com/3d-printed-gadgets/i_147_bike...

(3) Coil housing 2x - 3d printed part

(4) Spoke mount right - 3d printed part

(5) Universal magnet mount upper - 3d printed part

(6) M3 X 35 screw and a nut

(7) Universal magnet mount lower - 3d printed part

(8) Magnet housing screw - 3d printed part

(9) Locking nut - 3d printed part

(10) Adjustment screw - 3d printed part

(11) 5 mm white LED

Source: Any decent hardware store or ebay

(12) 1000µF, 16V capacitor.

Source: Hardware stores, in old electronics components, ebay

(13) 1 k Ohm, 1/4W resistor

Source: Any decent hardware store or ebay

(14) Diode bridge

Source: recycled electronics, ebay

How to make one:

https://www.instructables.com/id/AC-to-DC-converte...

You can use 4001, 4148... diodes, but for maximum performance use Schottky diodes (1N5818 or similar)

(15) 24V or 12V relay coil

Coil resistance should be aprox. from 250 to 1800 Ohms

Source: Old relays, ebay

(16) Main housing - 3d printed part

Step 1:

If you're using square relay adapter go to step 4.

If you're using a coil from an old 24V relay simply saw on the line marked with yellow on image 1. The only mistake you can make is to cut to deep ruining the coil. After the metal carrier falls apart you'll end up with what you need. Trim plastic flanges on both sides to make them round. Solder everything together based on scheme diagram (image 2) and you'll end up with a compact unit seen right on image 1. Coil orientation after assembly needs to be the same as left on image 1 (pre assembly).

Solder 1k resistor to positive side of 5mm LED as shown on image 3.

Step 2:

You need to drill a 6mm hole in to inner threaded part of main housing. There is already a 6mm indentation on the printed housing. Best way to do it is with a dremel, hot tip or a bore.

Insert LED with resistor in to drilled hole. Place coil-diode bridge-capacitor assembly in coil housing 1 and screw it in to main housing as shown on image 4.

Solder positive side of LED to positive side of capacitor and negative to negative.

Screw coil housing 2 in. Spoke mounted part is done. If you want to make it 100% rain resistant spray it with 1 rich coat of plastic acrylic paint primer and minimal 2 coats of acrylic lacquer.

Step 3:

Insert Neodymium magnet(s) on to magnet housing. You can stack anything from 4 to 12 mm of magnets in there. If you use more/stronger magnets then voltage induced in coil will be higher and led will shine stronger. This allows you to custom tune brightness. Coil housing has thread on inner and also outer side. After fitting the magnets simply secure by screwing adjustment screw in to magnet housing (image5).

Assemble universal magnet mount as shown on image 6.

Slide wheel safety LED on wheel spokes.

Attach magnet mount to bike frame. It's quite flexible so should fit on wide variety frame profiles and places.

Adjust everything so the coil passes the magnet with 1-2mm clearance (images 7,8,9).

You're done. Stay safe.

Step 4: Simplified Way of Installing Electronic Components

You have 3 different coil housing options to use depending on your coil size. Simplest to use is coil_housing_square with coil_housing_square_cover. This two files house a standard 24V, 10A relay coil such as: SRD-24VDC-SL-C. You don't have to "operate" the relay to get the coil out, you simply sand of one part of the relay and insert the whole relay. coil_housing_square has a support modeled on the internal side which you simply snap off or drill out after printing. Its the only model that has or needs any kind of support.

Check image 10 for following steps:

1. Relay before sanding.

2. Sand off the relay until you reach coil core. You will end up with relay about 12-13mm thick.

3. Solder the rectifier to the coil.

4. Insert the coil+rectifier to the new square coil adapter.

5. Insert the led diode with soldered resistor in the main housing then screw in the square coil adapter.

6. Solder the positive leads of diode and rectifier to positive capacitor side and negative leads of capacitor and rectifier to capacitor negative.

7. Tuck in all the wires. Screw in the new square coil adapter cover on and you are done.

<p>Just ordered a kit. One of the best instructables I've seen. Well thought out, clearly explained, modular and hackable. Nicely done.</p>
<p>I would do it in reverse - not the spokes to light but the rear light to be a red LED powered by dynamo/magnet on the spoke(s) .</p><p>Also replacing the rectifier is a great idea and the resistor is not needed you might not make too much current to burn the LED - if you do - then put more LEDs in parallel.</p><p>Also Joule Thief circuit might be e good idea and super-capacitor / ultra-capacitor.</p><p>Great - good work.</p>
<p>NO. The LED's are &quot;voltage&quot;- sensitive, that is: a standard (red) led has a forward voltage of ~ 2,1volt, and can manage ~20milliamps max. So, if you put higher voltage to the ledneed to &quot;eat up&quot; the owervoltage e.g. : if you put 6Volt on the led you need to eat up 6V-2,2V=3,8V and with 20mA that will be R=U/I =&gt; 3,8V/0,02A =&gt; ~ 190R. Therefore, it doesn't help if you put led's in parallel, the only thing you achvive with that is you have to eat up more Amps. But putting led's in serial you again have a problem, you get them to light with 2,2V+2,2V=4,8V?? Pleeeeease.... use a resistor</p>
<p>The idea is to increase visibility by having a rotating light source.</p>
<p>You may buy a rectifer bridge for ~20cents, to avoid &quot;miss-soldering&quot; (cold bridge etc.). The disadvantage with a full-bridge rect. is that you lose 0.7V ower the rect. diod. The advantage with a full rect. bridge is that you get a smoother DCV (flickering) at lower speeds.</p>
<p>you oughta make those an sell em that's a good idea</p>
<p>The idea is good &amp; doable. But go and check www.teksel.net. After <br>checking that, please continue from there giving us 'ables to build such<br> of our own?</p>
<p>Why do you use rectifiers, caused too much loss? You must switch instead two led diodes antiparallel.</p><p>Greatings, </p><p>Andor</p>
<p>Looking at the multicolor LED in <a href="https://www.instructables.com/member/ianmcmill" rel="nofollow">ianmcmill</a>'s video, how about having a red LED turn on when slowing down or stopping (staying on for more than few seconds) while the white LED turns on as you speed along ?</p>
<p>First thank you for the great tutorial. I tried to do it on my own but it didnt work out. I bought a 24V relay, 220 ohm (FIN 40.52.8 24V) and some neodymium magnets (N48, 15x5mm). But the coil only works when the magnet TOUCHES the coil. @ianmcmill which relay coil did you use exactly? Thanks for the help.</p>
<p>Check Step 4. I used: SRD-24VDC-SL-C. I recently designed additional coil housing which makes it really easy to install and is back compatible with the rest of the design. You can use the whole relay without having to remove the coil. Or just remove the coil and use old 3d files.</p>
<p>I designed 2 new components which simplify installing electronic components a lot. Check step 4 for details.</p>
<p>I had few request for full kits so here they are: </p><p><a href="http://hotmess3d.com/3d-printed-unique-gifts/i_148_bike-induction-safety-light-full-kit" rel="nofollow">http://hotmess3d.com/3d-printed-unique-gifts/i_148...</a></p>
<p>I made one! Check it out on 4k! Albeit it does not fit my spokes. I have a mountain bike and main housing does not fit the spokes. I fixed one side on a spoke using the spoke mount and the other side using a zip tie. Should be enough. Nevertheless, turning the pedals while the bike hangs on the wall, the wheel really wobbles like hell :) Need a second one as a balance weight. Trying to construct one on my own in Fusion.</p><p>Nice project tom4zs.</p><p><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/9waQELmzgBY" width="500"></iframe></p><p>Electronic parts used:</p><p>Capacitor: 1000uF 16V<br>Coil: 12V Omron relay coil - 250ohm<br>LED: REG automatic rainbow LED. 3.8V 30mA<br>Resistor: 460ohm 1/4w<br>Rectifier bridge diode: 4x 1N4148</p>
<p>Looking good. 2 simple upgrades to increase led brightness: Drop an extra magnet in magnet housing and use <b style="">Schottky diodes for diode bridge.</b></p>
<p>I wondered if SMD rectifier diodes work as well. Reduces build volume.</p><p>I use 4x 12x3mm N50 neodynum magnets. Each can lift 3.5kg.</p>
<p>An extra 0.5 volt from using 0.2 voltage drop diodes should make a decent improvement in brightness. 4001, 4148.. drop 0.7 volts.</p>
<p>Oh now I understand. Thanks. So I have looked aroudn reichelt.de and they offer a large variety of schottky diodes. One like this: </p><p>http://www.reichelt.de/BA-BAY-BB-Dioden/BAT-48/3/index.html?&amp;ACTION=3&amp;LA=5&amp;ARTICLE=4855&amp;GROUPID=2988&amp;artnr=BAT+48</p><p>This one has a UF (forward voltage) of 0.25V; an IFSM (max current) of 7.5A. How much current is produced approxiamtely by our circuit? </p><p>There is an even smaller diode (-0.7mm in length) with an UF of 0.24V but it's IFSM is only 0.6A.</p><p>http://www.reichelt.de/BA-BAY-BB-Dioden/BAT-85/3/index.html?&amp;ACTION=3&amp;LA=5&amp;ARTICLE=4857&amp;GROUPID=2988&amp;artnr=BAT+85</p>
<p>The smaller the better. I did some testing for another project where i used 24v 5 pin relay coil with 1660 ohms resistance mounted on bike frame and 4 magnets mounted in 90 degrees interval on wheel spokes. At 25 km/h it produced Steady 1.7mA thrue 3mm blue led. Even with improved voltage from using schottky its safe to say you can use for example 1N60P rated for 45V; 30mA or 1N5818 which is rated for 1A; 30V or anything appropriate in between. I don't really know benefits and drawbacks of using either extreme. </p>
<p>This is awesome! I made one and it works great. Can anyone explain the selection of the optimal relay coil? There are a lot of different coils out there. Is the voltage rating of the coil important or just the resistance? Does it have to be a relay coil or would any inductor work? Which type of coil produces the most power for a given magnet and magnet distance (geometry)? What is the lightest weight coil or coil-geometry that will generate the most power? Thanks.</p>
<p>Quite few people requested full kit for this project so I'm actually testing coils at the moment to source a cheap and efficient one. Those 24V power relay ones are to expensive. Ill get back to when i figure something out.</p>
<p>I have tried 2 relays. </p><p>The first and second picture shows an Omron 24V relay. The coil is 20mm high and has a diameter of 10mm. Resistance is 1100 ohm. The pins where the wires connect are very fragile. I already killed 3 relays in the process. On eBay I bought 7 for around 9&euro;.</p><p>The third picture shows a car relay. I guess it's 24V. It is 16mm high and has a diameter of 15mm. So this doesn't fit.</p>
<p>Which one do you want to use first? Ill add a housing for it to thingiverse files.</p>
<p>Hey. I have tried a 12V relay. It's resistance is 250ohm. I managed to solder everything together and it worked. I used a 3.8V 30mA rainbow LED and manually passed a magnet along the coil. It lit up and showed the first 2 colors. Albeit very dim, it worked. Then I wanted to insert it into the housing and realized I had to desolder again so I could build everything together. And tehn I realized that I soldered the LED to close to the capacitor, so that when I screwed in the 2nd housing containing the coil, the LED head interefed with the thread of the coil housing.</p><p>Anyways 12V coil works but I could not test it on my bike and see if it generates more light.</p>
<p>Heh yea there is no other way to put it together then as described in Step 2.</p>
<p>The pins on the Omron coil are pretty fragile. The car relay coil is to wide, so this would need a wider housing and therefore a new main housing. I don't know. </p>
<p>I added an extra file for longer coils. <a href="http://www.thingiverse.com/thing:907511" rel="nofollow">http://www.thingiverse.com/thing:907511 </a> </p><p>File: coil_housing-long (repaired).stl. Inner diameter is the same as original (14mm). Storage length increased from 17.5mm to 22.5mm.</p>
<p>Cheaper relay coil that is right dimensions and performs well: <a href="http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Mini+Relay+SPDT+5+Pins+24VDC+10A&_sop=15" rel="nofollow" style="">http://www.ebay.com/sch/i.html?_from=R40&amp;_sacat=0&amp;...</a> </p>
<p>Do 24V relays work better than 5V relays? Also how important is the 1000uF on the capacitor? Would 100uF work just as well?</p>
<p>Too bad they ship from Thailand. I want it now :D</p>
<p>In step 2 you have to drill a hole for the LED. Why didn't you print the hole? Is there some reason why it is better to drill it then to print it?</p>
<p>Because i wanted LED to as exposed as possible. If you FDM print with a hole you get an extra 1mm or so of material wrapping the LED. Holle takes 1 minute to make with dremel or you can add a deeper hole and just print.</p>
<p>Another idea: How about making the massive part of the main housing hollow?</p>
<p>Ah very clever! Really nice. Printing software needs more options to configure specific parts of a model with different settings for slicing. Thanks!</p>
<p>There is nothing new or unique about this circuit. They've been around for over 60 years. You could get a design patent on your housing, nothing more.</p>
<p>Yes components are cheap, simple and have been used in similar configurations for ages. What I like and wanted to share was the beauty of how well they are put to use in this project. There is also the fun of making something custom+useful with 3d printing.</p>
<p>The circuit might not be new, but its new use might be unique enough for a patent. Maybe.</p><p><a href="http://howconceptual.com/patent-new-use-of-old-idea/" rel="nofollow">http://howconceptual.com/patent-new-use-of-old-ide...</a></p><p>I do love this idea BTW.</p>
<p>Another cool idea would be to use a strip of acrylic glass and insert the LED at one end to have the edge illuminated. This way the main housing could be saved from printing.</p>
<p>That would look awesome yep. You just need to figure out how to attach the parts that house coil and capacitor. I designed 3d printed version with thread so you simply screw them in.</p>
<p>I wonder about the relay. Where can I get this from?</p><p>Awesome project!</p>
<p>I had few relays laying around, but if you need to buy one i did a quick ebay search: <a href="http://www.ebay.com/itm/National-HC-RELAY-type-HC-4-DC24V-4PDT-4-Form-C-5A250VAC-MATSUSHITA-ELECTRIC-x1-/261939872682?pt=LH_DefaultDomain_0&hash=item3cfcd543aa" rel="nofollow">http://www.ebay.com/itm/National-HC-RELAY-type-HC-...</a></p><p>Looking in to other cheaper and more suitable coil sources. But that's it atm.</p>
<p>Thanks! I do not have any knowledge about circuits except for soldering by instructions so I have another question. I am using a RGB automatic rainbow LED. 3.8V 30mA. I wanted to calculate the resistor and found some online scripts to do so. Yet if I try to replicate your result of a 1kOhm resistor I fail.</p><p><a href="http://led.linear1.org/1led.wiz" rel="nofollow">http://led.linear1.org/1led.wiz</a></p><p>3.8V LED; 30mA; Source voltage 16V (from the capacitor???)<br>= 680 ohm 1/2watt</p><p>Does this has something to do the with wattage ??</p>
<p>Source voltage will never be 16 V its just max. the capacitor can take. I used 1k resistor to reduce current drawn making led shine longer less bright though. Anyway led is always on and uses all the current generated so voltage will never get higher than lets say 3.8V (depends on resistor you use and). You can use any resistor from 47ohm to 1kohm making your led shine shorter but brighter or longer but less bright.</p>
<p>Thank you.</p>
<p>Or could I use a coil from a transformer from an old power supply?</p>
<p>This was the thing which i always desired to make since 2 years.i really congratulate to him who made it.</p>
<p>Nice. Just a note, you only need a single rectifier (albeit in the correct orientation).</p><p>That'll save you 0.7 Volts :-)</p>
<p>I will test that, thank you.</p>
I've just tried the single rectifier and I'm wrong, sorry :-(<br><br>The polarity coming from the coil changes as the magnet passes,<br>
<p>Now that i think of it i think i tried half wave rectifier to somewhere along the way with poor results.</p>

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