EM Textile (Heating Pad or Electric Blanket with EM Frequencies)

This EM tech is a fairly new idea, using existing technologies to put together something affordable and easy to assemble for laymen. This does not utilize 'harmonics' the way some EM techs do (such as plasma tubes) but only the frequencies specifically sent from your signal generator. This is a 'contact' tech (directly touches your body). This is applied for longer duration than plasma-type techs (hours vs. minutes). This is a 'body conductance' tech (assumed to reach your entire body no matter where contact is located).

Credits:
Brilliant idea: Carmi Hazen (see his books)
Posted on discussion list of: Ken Uzzell (see Yahoo Groups, FreX)
Details for electronic assembly by: Bil Green (many thanks Bil!!)
This write-up (send any errors or additions to): PJ Gaenir at DIY-EM

Information on this page:

1. Supplies: list of items, details, pictures, examples, pricing.
2. Assembly: step by step assembly instructions.
3. Accessibility: narrated youtube slideshow video (coming eventually).

Supplies pricing: ranges from around $65 to $100 US as of Sep2013. Dependencies include whether you have any components on hand (such as for box/cover and cables), whether you can buy things locally (vs. online with shipping), and your choice of components (e.g. length of cables or type of wired textile).

1. Amplifier: 20 watts, must be "RMS"

Example:  30 watt [15x2] Pyle PFA100 Hi-Fi Stereo Amplifier (with 110V AC to 12V DC, 2A adapter){Very small 8W “RMS” per Channel) (found for ~$27 US + s/h in Sep 2013 USA)
Amazon Product Example

I selected this model because it has an output of around 8 RMS watts per channel (higher wattage is OK) and the proper input and output connectors for this project. Yes, I know they claim 15 watts per channel, but that’s not possible with a 12V, 2A power supply which provides only 24W maximum. May be available at some stores that sell electronic equipment.
-- Bil Green

2. Transformer: 70 volts, 5 watts, must be "Line-Matching"

Example: 8 ohm to 70 volts 5 watts line-matching transformer
(found for ~$8 US + s/h in Sep 2013 USA)
eBay Product Example

Buy the 5 watt one so you can use a smaller AC outlet box to mount it. The 10 watt one will work though.   Not available at hardware stores.
-- Bil Green

3. Outlet: standard size, double, 3-prong AC outlet

Example: Leviton T5320-W 15 Amp, 125 Volt, Tamper Resistant, Duplex Receptacle, Residential Grade, Grounding, White (found for ~$4 US + s/h in Sep 2013 USA)
Amazon Product Example



4. Wired Textile - Heating Pad or Electric Blanket with only on/off or non-digital control switch

Example: Conair heating pad model AGF-1HP-1 or HP01RBRR (found for ~15-17 US in Sep 2013 USA)
Amazon Product Example

Must not have an electronic control. This Conair heating pad model AGF-1HP-1 just has an on-off switch. This is what you need (no digital/electronic control). One which has an old style selector switch which clicks as you turn it would be OK too (with no electronic display!). Or buy at a local store.
-- Bil Green

5. Containing Elements - Housing, cover and attachment
Housing for transformer and outlet; cover plate/s; some form of attachment (either 3 bolts and nuts, or thick double-stick mounting tape)

Example 1:
Box: Double or triple-gang standard (but "deep") outlet box.
Cover: If double-gang, you can probably find a double 'cover plate' with one side for the double AC outlet and the other solid or at least very small opening (the solid area would go over the transformer). It may be harder to find a triple-wide cover plate but you could use more than one to cover the box, the point is just to make it neat and reduce chance of dangerous (this can be fatal) electrical shock.

Example 2:
Box and cover: You can use any container that would allow you to firmly place the components inside, plug into the outlet, and protect the components so accidental electrical contact will not occur. Such as a heavy duty plastic food storage container, using double-stick tape, and a hole cut in lid for the outlet.

6. Connections: Cables - Stereo mini (3.5mm) (M) to RCA (M:M) cord; at least 10' of flat 14 AWG 2-wire (14/2) Zip cord; two very small plastic wire nuts

First connection: Amp to transformer, the 14/2 zip cord.
10 feet is about $3 US; 50 feet about $22 US (Sep 2013). (see wire nuts below)

More than enough to run from the 70 volt transformer to the heating pad or blanket. Consider the distance going down from a desk or table top and up from the floor to the pad or blanket. – this is usually available in black, brown or white. Found at all hardware stores.
-- Bil Green

Plastic wire nuts for twisting the zip cord: you only need two.
I ordered 100 from paypal ~$8 (Sep 2013).

To attach the speaker output of the audio amplifier to the transformer - 2 very small gray ones (the smallest ones are sometimes orange). The ones with a spring like interior are the best. Do not use the large orange ones.  Found at all hardware stores.
-- Bil Green

Second connection:  3.5mm male stereo to double-male standard RCA cable.
6' is about $4 US; 12 foot about $10 US (Sep 2013).
Amazon Product Example (this a 12' example): eBay Product Example (6')

The little transformer and stereo amplifier will need to be fastened to something so they don't go flying off the table when someone steps on the long wire going to the heating pad or blanket. And the “70” volt transformer (the voltage is far higher than 70V at some frequencies) wires insulated to prevent dangerous electric shock. Best to have them on the floor so there's no where to fall off. See my instructions for assembling the AC outlet box. You only need to mount the transformer (even double stick tape can be used) and make 4 wire connections. Very easy to do and prevents someone (like a baby or pet) from getting electrocuted. Not available at most hardware stores.
-- Bil Green

Here are the assembly instructions from Bil Green. First a simpler version, then one with more details. I intend to modify this a bit when I get all my components and assemble it, to include pictures of the assembly points and anything I learned / had to ask about in the process.

Brief Instructions

Overview

Inside the box mount a double AC outlet on one side and the 70 volt transformer on the other side "after" everything is wired up.

1. Feed the speaker wire through a hole in the outlet box and tie a knot (leaving about 3 inches of wire inside the box).

2. Strip and attach* the 2 wires to the transformer, one to the 8 ohm wire, and the other to the "common" (Com or C) wire. Both these wires are on one side of the transformer.

*Use the wire nuts to insulate and fasten tightly (always twisting to the right).

3. On the other side of the transformer attach the common and highest number wire as follows. One wire to either of the "main" screw terminals of one AC outlet.

4. Attach the other wire to the "other" AC.outlet as above. Do NOT use the ground terminals.

Yes, only one terminal of each AC outlet is used. The blanket or heating pad actually acts as an antenna.

5. Mount the AC outlets, the transformer and cover plate. The transformer is mounted with the 8 ohm wires facing the short side of the box

Detailed Instructions

1. Hold the outlet box so that one of the long sides is facing up and and make a hole in the "center of this side large enough to fit the zip cord or speaker wire.

2. Pull the wire through and make a tight knot leaving about 3 inches of wire inside the box

3. Strip both ends of the wire that you fed through the box. Strip the  8 ohm wire and the common (COM or.C) wire that is  on the "same" side of the transformer.

4. Twist the end of the 8 ohm wire onto one of the speaker wires. (twisting to the right only) and the common wire onto the other speaker wire. Now fasten each connection with a wire nut. (twisting it to the right).

5. Drill holes or use tape and mount the transformer with the side which has the now connected wires near the short side of the outlet box. Leave plenty of room to mount the double AC outlet.

7. Attach the common (Com or C) wire.from the other side of the transformer to either of the "main" terminals of one AC outlets. Do not use the ground terminal.

8. Attach the.transformer wire with the highest number to the other AC outlet (either of the.main terminals). Do not use the ground terminal.

C or COM on one wire, other one will say 20W - use the - on the paper/plastic sealed on transformer

how do you know which is the ground terminal on outlet? green screw. diff size than other screws. usually one screw on each side.

9. Mount the AC outlet and cover plate