A Tens machine is used to provide a drug free way of removing pain from your body ( TENS stands for Transcutaneous Electrical Nerve Stimulation )
.Here I will show you how to build your own Tens machine and reduce the amount of pills you use to stop pain .To Build this Tens unit, you will first need to buy a 555 timer IC . The 555 timer is very small about a quarter of the size of your finger nail .You can purchase one for about 25p from Maplins or Radio Shack etc .

There are 2 types of Tens machine. High Frequency Tens uses frequencies in the range of 80 to 100 Hz. This blocks the pain impulses going to the brain .

Low frequency Tens uses frequencies from 2 to 4 Hz . This will help the body produce its own endorphins and increase local blood flow to relieve pain ( this can last for hours ) .

Square waves are universally encountered in digital switching circuits and are naturally generated by binary (two-level) logic devices. They are used as timing references or "clock signals", because their fast transitions are suitable for triggering synchronous logic circuits at precisely determined intervals. However, as the frequency-domain graph shows, square waves contain a wide range of harmonics.

Step 1: Ooop's Statutory Warning

WARNING: The device is not designed for use above the neck or for individuals who have a pacemaker or other heart defects .This device should not be used by pregnant women & Girls .

SQUARE WAVE TRAIN
The “Square wave” permits the frequencies to penetrate the body more efficiently at any given Khz output. Square waves are considered the superior “frequency to wave” output for any Frequency generator device.

Step 2: 555 Timer IC

I first started off placing the 555 timer in the center of the project and then build arround it .
A close up look of the Diagram will show you how the Pins from 1 to 8 on the 555 Timer is connected up . You can use this magnification to reference back to during your project .

Each pin is numbered from 1 to 8 .

Step 3: How the Square Wave Is Generated

The ratio of the high period to the total period of a square wave is called the duty cycle. A true square wave has a 50% duty cycle - equal high and low periods. The average level of a square wave is also given by the duty cycle, so by varying the on and off periods and then averaging, it is possible to represent any value between the two limiting levels. This is the basis of pulse width modulation.

Parts List for a Low Frequency Tens Machine ( Generating the Square Wave ):

(1) 205 K ohm Resistor
(2) 233 ohm Resistor
(3) 5.01 M ohm Resistor
(4) 10 nF Capacitor
(5) 47 nF Capacitor
(6) 555 Timer IC
(7) 28.81ma Light Emitting Diode
(8) Rocker Switch
(9) 9 volt Battery
(10) Thin wire
(11) Solder ( and soldering iron ) or small bread board
(12) Home made conducting pads made with stiff copper wire covered with Foil .

Once all the parts are together you can start to wire up your project.

Step 4: Low Frequency Tens Machine Diagram ( Wave: Asymmetrical )

We are building the Low Frequency Tens Machine at the moment .
Once all the parts are together they should be placed out and wired up shown in the diagram . You could either solder them together or connect them using a very small bread board .

If you find it difficult to see the values in the diagram, these are what they are :

(1) 205 K ohm Resistor
(2) 233 ohm Resistor
(3) 5.01 M ohm Resistor
(4) 10 nF Capacitor
(5) 47 nF Capacitor
(6) 555 Timer IC

When you wire up the the Light Emitting Diode, the resistor should be connected to the ( a or + ) Cathode ( the Long Lead ) side of the Light Emitting Diode .The short side connected to the negative or ground side .

Step 5: High Frequency Tens Machine ( Wave: Asymmetrical )

To change your device into a High Frequency Tens Machine, you only need to replace 2 resistors .

Replace the 205 K ohm resistor with a 6.8 K ohm resistor
and
Replace the 5.01 M ohm resistor with a 167 K ohm resistor

(1) 6.8 K ohm Resistor
(2) 167 K ohm Resistor

The 2 red conducting pads shown in the diagram are the silver Foil covered pads to be placed on the body . To increase conductivity you can use hair Jell on the pads . Although you will not cause any damage to the unit, the +/- conducting pads should be kept apart from each other.

Here's a link showing proper placement of electrodes.

http://www.tens-store.com/ems/tensplacement.htm

You could place your finished project inside its own case . Remember to remove the batteries when not in use.

You can simulate this circuit by downloading some software on a free trial . Choose Electronics because the software has a number of Scientific options . Go to :

http://www.yenka.com/

Step 6: A CURE FOR ALL DISEASES ?

To change your device into a medical device to cure diseases, you only need to replace 2 resistors and 1 Capacitor .

Replace the 6.8 K ohm resistor with a 9.6 K ohm resistor.
Replace the 47 nF Capacitor with 100 pF Capacitor
and
Replace the 167 K ohm resistor with a 236 K ohm resistor

Parts List

(1) 9.6 K ohm Resistor
(2) 236 K ohm Resistor
(3) 100 pF Capacitor

This would give an out put of 30 k Hz , to kill parasites in the body, raise the ph to remove acidic environments in the blood . Allow healing Lymphocytes to do their job properly .
The Square wave formula for all square waves is below . You can also visit this website for more information about what your device can achieve . Although their device is out of range of the Low Frequency TENS that you will be building .

http://www.huldaclarkzappers.com/?gclid=CPaXy77zkJwCFZgU4wodj1MCcQ