Picture of The Electric Heated Sweater

Hey Guys welcome to our Entry for the Sew Contest Ins. We made an Electric Heated Sweater that uses a 9v battery to heat up your sweater. It works great yall should give it a shot. Just make sure to follow the instructions and you use a sweater that you dont really love! cuz you wont be able to wash this sweater EVER AGAIN!

 Important safety point: only use this is a  pure-wool sweater, or one with proven heat resistance.  Many synthetic fibres melt at surprisingly low temperatures

Visit our website at www.hm-innovations.com for additional videos and projects. We hope you enjoy what we did :) 

Step 1: Getting your 20 Gauge Wire

Picture of Getting your 20 Gauge Wire
You have to meassure your 20 gauge ENAMEL copper wire to your desired lenght. Usually about 5-6 feet. This really depends on the size of your sweater :P
Could you dry clean it????
joehudy4 years ago
you r basikly just short curcitingt the battry so ovcorce its going to heet up.wold using a camra circut work ?
Well, Using a camera circuit output's a very high voltage to recharge the capacitor for the flash circuitry. The circuit does not output enough Amperage to heat up a copper wire enough for it to do significant heating.

Short circuiting the battery? Not really, because the battery has something to output to, and takes longer for it to actually get to the battery, it will heat up, but not because it is short circuiting. It would heat up slightly (or even more than slightly) because of the discharge of electrons that were stored in the battery.

bobtannica4 years ago
I decided to experiment with this before I tried "sewing" it in the clothing. I took a 3 foot piece of 22 gauge enamel coated magnet wire. (It's what i could find) I soldered on a 9 volt battery connector making a simple loop. I used no switch for the experiment. When I connected the battery, the only thing that got hot was the battery. Any thoughts as to what I did wrong? It's a great instructable and I hope to be able to make use of it but really need some help, please. Thanks.
HM-Innovations (author)  bobtannica4 years ago
That happened to us too several times, we took the idea from a website a long time ago and the first few times we were unable to figure it out. We know you have to use very THIN, magnetic wire maybe? it works with the same principle as a heated blanket but with much less power. If the battery is getting hot, dont risk it it could explode. Maybe add two batteries ? I wish i could be of more help I'm sorry

When you say add two batteries...do you mean in series or in parallel? Oh... the wire I used was 22 gauge which is actually thinner that the 20 gauge you used. Could it maybe be that there wasn't enough resistance for it to heat the wire and therefore the battery got hot?
HM-Innovations (author)  bobtannica4 years ago
I think that might be the problem... I wonder if adding a diode at the end of both terminals work?
for one thing, the resistance is actually greater in a thinner wire, which could "burn out" more easily (try the same test with steel wool.) The diodes may work, but it seems unlikely. sorry to burst your bubble!
emanb29 thanks for your contribution but I am unclear as to the solution here. I know what you mean about steel wool. When hooked to a battery. It actually burns. Ruben suggested putting two batteries but I don't see how that would fix the problem of the battery heating up. Is the problem that the smaller gauge wire increased the resistance and the battery heating up was in response to needing more "push" to get the electrons from one terminal to the other and adding a second battery will give that increase? Any helpful suggestions would be appreciated as I am very interested in this idea!
Possibly, I should say some sort of insulated thick (16g or so) wire should heat w/o heating the battery. High-insulation wire is used in stoves, so possibly if you pass less current through teflon insulated wire it wouldnt be TOO warm. "Microwire" supposedly works but I don't know where to get it.

emanb29 emanb294 years ago
After much research on this project, I discovered the reason for my failure through use of ohm's law. Using 18 feet of this wire (enough to make a lattice over the back) My 9v would need to supply over 48 amps, about 43 more than the battery could according to the datasheet
V1x0r4 years ago
Might i suggest a dc-dc boost converter instead of a 9v battery. if you need more power for longer than set up more batteries in a parallel. (NOT SERIES!!). you use the fuji joule thief circuit (pirate labs method is better than josepinos...josepino gets very close...but removing a few more things from the circuit increases wavelength output).

If you get a standard 4AA battery holder and modify it so that the batteries are in parallel and NOT series (so input is still 1.5v) you will output about 20-60v...depending on which method you use. some people get more than that too. and the battiers last longer than your current method.

now, why not go through a little more and make the unit detacheable? take a thin cloth and attach the wiring to that, put some velcro on it and attach on the inside of the sweater. now you have a patch and you can use on multiple clothes.

anyways, hopefully this is helpful for you guys. cool idea too.


enjoy peeps!!

check out overunity"dot"com and look under joule thief
get your basic design from http://josepino.com/circuits/fluorescent_light and modify using overunity.

hope you guys enjoy!!!

HM-Innovations (author)  V1x0r4 years ago
Very Awesome Idea! Thanks for the input
bobtannica5 years ago
I was wondering if you could substitute a charger that puts out 6v at 500mA for the battery?
wazupwiop5 years ago
I am no electrician, but this seems a little dangerous.  Firstly, the people who would need this are diabetics and there is a disease where the body cannot control its own temperature.  This means that it would probably get too hot a burn them because they are less sensitive to heat.  Secondly, the plastic is going to get hot and melt.  Have you ever used a soldering iron and seen it?  Overall, it is pretty cool, just not safe.  I, personally, would make a circuit with a few resistors to control how much heat you wanted
you dont need a resistor if you use the right size battery. if you check the resistance of the wire used then you can figure out the current. if that is too high, then use a resistor. if not, there is no need
Also cold weather motorcyclists (i.e. me) would find this useful (and I do).
If you wanted it to be rather strange, you could attach a small wind turbine to the front of the jumper, so when it is cold and windy, it heats up, otherwise it stays off!
knektek5 years ago
only 20 mins of use here. if you use rech 4 X D size cells, about 1 - 2 hrs of use.
Doctor What5 years ago
 Fire hazard?
HM-Innovations (author)  Doctor What5 years ago
possibly if youre not smart about it and leave it on all night and day. Anything electric can be fire hazard in the wrong hands :P
Make sure you use a heat resistant material jumper (not nylon for example).

Might be worth looking into a small thermostat to cut it out at a set temperature.
HM-Innovations (author)  el greeno5 years ago
I thought about installing a resistor that shuts off depending on heat, but i dont know if they exist at all
Fuse wire?
How about just a variable resistor and just let the person dial it up slowly?
Kiteman5 years ago
Important safety point: only use this is a  pure-wool sweater, or one with proven heat resistance.  Many synthetic fibres melt at surprisingly low temperatures.
HM-Innovations (author)  Kiteman5 years ago
Thanks I should have added that earlier
Cool - word-for-word!