DIY 12v Heated Vest
February 2nd, 2007 at 10:08 pm (general posts)
I started on the heated vest…
Using this site as my main guide the first step was to buy;
30 gauge, multi strand teflon coated copper (100′)
from RAE Industrial Electronics
Halifax, Nova Scotia
www.rae.ca
$24.86
A truly thorough person would have calculated the length of wire using Ohm’s law but I just used the first reference to a length that was reported to provide good heat. It’s 30 feet. In trying to calculate things the question arises of “how many watts” does one want. How would I know? I don’t measure a comfortable heat in watts but in degrees.Remember also that some of the sites use 12v in the calculation, when in fact a motorcycle produces closer to 13.5v when running. In any event if it’s too hot I’ll add a small controller. Value Village provided a $3.90 fleece vest that I trimmed down to fit inside my MEC fleece jacket.
I hot glued the wire as I was going to hold it in place. Maybe the glue will melt when the vest is powered up… not sure. As a safety measure I taped it down at strategic locations with adhesive metal foil tape. I assume if the adhesive directly under the wire softens the rest of the tape patch will stay adhered to the fleece.
The vest was glued into the fleece jacket with hot melt glue. I left the wire ends dangling and stripped and as a test connected my portable 12v power supply (a booster pack). It sparked at the second connection and the wires almost immediately became warm, not hot but warm. The heat permeated the fleece in a couple of minutes.
I had a test subject wear it (thanks Peter!) and hooked it up again and it heated up. My concern is that the wires will break while putting it on and off but that’s probably unfounded as the wire is very strong and I left lots of free play in the loops. I need to add some more glue between the vest and the jacket.
Next step is to solder or crimp some heavier gauge wire and a connector of some sort to the wire ends and to fasten that part very securely with glue or wires ties and Goop or something. I should have this done today and will try plugging into my car 12v accessory outlet. Hopefully with the 13 or so volts from the running car it will be warmer - I’m sure it will be.
UPDATE on February 4
The vest is all glued in place and wired and tested and it works great! I tried it in the car with engine running and it’s like an electric blanket at a low setting, which is perfect. I’m curious how it will be on the bike. If it needs an adjustment capability I will order one of these tiny kits.
Here’s the connector I used - $3 at Canadian Tire - I soldered the connections and used heat shrink tubing wherever possible, keeping in mind the objective to make the joints as stable as possible - i.e. no flexing. Note that after this photo was taken I re-did these connections with properly sized shrink tubing.
