Introduction: How to Build a Real Working "Brain Ray" (Transcranial Magnetic Stimulation Demo)
In this instructable, I will show you how you can demonstrate the ability to stimulate neurons in your arm to make you twitch without invasive methods. Essentially, you will learn how to construct your own single pulse "brain ray!" You will be a real "brain hacker" and this is excellent for science fairs.
This device differs from those in the medical field in that it is lower power and only shoots one pulse at a time, while medical TMS machines pulse continuously.
Step 1: Collecting Capacitors
Collect a bunch of used disposable cameras. These may often be picked up for free at stores where film is developed. Take the guts out of each camera wearing gloves with rubber insulation. Discharge the capacitor in each camera for safety using a metal object. You will need to salvage 54 120uF capacitors.
Step 2: Make a Capacitor Bank
Create a capacitor bank by arranging 6 rows in series of 9 capacitors in parallel as shown in the video. Wear protective gloves while handling these capacitors or working with high voltage.
Step 3: Make the Coil
A coil is needed to create an electromagnetic pulse to induce current in neuronal tissue. Create a coil with 15 turns of heavy duty wire. Make sure that the wire is insulated. For my coil, I wrapped it up with electrical tape and added a tube where users can grip it.
Step 4: Arrange the Circuit
Create the circuit as shown in the video. Connect the capacitor bank to a switch and then the coil of wire so that the switch dumps the capacitors' stored energy into the coil when turned "on," Use a heavy duty switch.
Step 5: Charge the Capacitors
Use a charging circuit from one of the disposable cameras to charge each row of the capacitor bank as if it was charging a single capacitor. There is usually a button on the back of each charging circuit that would have been the "charge" button on the camera. solder the button so that is is always turned "on." Use alligator clips to connect the charging circuit to charge each row, paying attention to the polarity of the capacitors designated by a stripe on each capacitor's side.
Once all of the capacitors are charged (check using a voltmeter and while charging the capacitor bank wear rubber insulated gloves) place the coil over a spot on your arm. If you place in in the right spot, your hand will twitch and/or you will feel the pulse! This means that your trans-cranial magnetic stimulator is a success!