elte
Nov 25, 2015 02:23 AM
(This post was last modified: Nov 25, 2015 03:09 AM by elte.)
If one doesn't mind carrying a small battery, heated clothing can cut energy bills by great margins. A person who gets cold easily can even benefit greatly.
The key is high temperature magnet wire. I used the the type rated for up to 200°C. Another thing of key importance is to bend the wire back at the half-length point, and then twist the wires together into twisted pairs. Then that twisted pair can be twisted in half again to reduce the length worked with to 1/4 the original length. A thing the twisting does is take small gauge wire and give it some with-wise bulk so it is easier to handle. Also, the second twist pass removes the tendency of the twisted pair to twist back on itself into a twisted tangled mess. Lastly, the twisting cancels out radiated electromagnetic waves from the wires, or if operated off of pure DC from a battery, cancels out a plain magnetic field. Canceling radiated fields is a main reason I did it with twisted wires.
I began each heater element with 50 feet of 30awg (gauge) wire. After the two passes of twisting, I had a wire about 12.5 feet long. Connecting two of those in series to 24vac produces about 6 or 7 watts of heat in each, ca.13w for both. I use four total for something like 27w. I have a DPDT switch that can place each pair that are in series themselves in series for a total of 4 in series. That cuts the power in half, total, down to 13w, about 3w each. So, I can set them either to 13w or 27w, or something close to those figures.
So, I didn't use a battery and just use my heated pads in one basic spot connected by 24awg speaker wire to a 24vac, 60hz, 100va transformer. The circuit is protected by polyswitch fuses to protect against short circuit failure modes. The container for the pads are 1lb split pea bags, reused. Those bags are what the wires are stuffed into. They are spread out in the bag and made flat for inserting under clothing, but preferably on the outside of underclothes. So they should be between the bottom layer and additional layers of clothes over that.
The key is high temperature magnet wire. I used the the type rated for up to 200°C. Another thing of key importance is to bend the wire back at the half-length point, and then twist the wires together into twisted pairs. Then that twisted pair can be twisted in half again to reduce the length worked with to 1/4 the original length. A thing the twisting does is take small gauge wire and give it some with-wise bulk so it is easier to handle. Also, the second twist pass removes the tendency of the twisted pair to twist back on itself into a twisted tangled mess. Lastly, the twisting cancels out radiated electromagnetic waves from the wires, or if operated off of pure DC from a battery, cancels out a plain magnetic field. Canceling radiated fields is a main reason I did it with twisted wires.
I began each heater element with 50 feet of 30awg (gauge) wire. After the two passes of twisting, I had a wire about 12.5 feet long. Connecting two of those in series to 24vac produces about 6 or 7 watts of heat in each, ca.13w for both. I use four total for something like 27w. I have a DPDT switch that can place each pair that are in series themselves in series for a total of 4 in series. That cuts the power in half, total, down to 13w, about 3w each. So, I can set them either to 13w or 27w, or something close to those figures.
So, I didn't use a battery and just use my heated pads in one basic spot connected by 24awg speaker wire to a 24vac, 60hz, 100va transformer. The circuit is protected by polyswitch fuses to protect against short circuit failure modes. The container for the pads are 1lb split pea bags, reused. Those bags are what the wires are stuffed into. They are spread out in the bag and made flat for inserting under clothing, but preferably on the outside of underclothes. So they should be between the bottom layer and additional layers of clothes over that.
