tDCS Devices, Designs & Advice
  • Dr_AllcomeDr_Allcome June 2016
    The thread title says it all.

    I'm interested in experimenting with tDCS and having searched the wiki and read the threads, I found several thread/comments from a while back and a couple of product links that don't seem to be active anymore.

    Google turned up a huge number of products, suppliers, and projects, a-lot seemed aimed at gamers, many of the DIY projects are old and vary greatly in complexity and size.

    I'm looking for advice either on current products to consider buying or links to (validated/tested) designs/projects that people have experience with or consider worth the effort.
  • McSTUFFMcSTUFF June 2016
    I built a couple and wrote instructions for making copies. They're not validated by any governing authority nor do they contain a redundant safety system. Use at your own risk.
    2mA tDCS
    Adjustable tDCS

    The 2mA version was written for a workshop done with minimal tools and experience which is why every little step is described. The Mouser BOM link is still good though.

    The adjustable version was something I hacked together for myself because I wanted to prove the adjustable version was cheaper and more versatile although more difficult to build.
  • kuroro86kuroro86 June 2016
    I use this:

    https://thebrainstimulator.net/product/travel-model-v2-tdcs-device/

    I can't give you any test by government. The very few that are tested by government are or restricted to researchers or are really expensive. 
  • Dr_AllcomeDr_Allcome June 2016
    Thnx, have continued researching:

    I wasn't looking for/expecting any formal certs or test of products just any personal experiences :)

    Some of the commercial devices out there looked like crap, others looked great but were expensive and one happily claimed to get up to 80v output which just seems like overkill... most of the smaller units locking mA to duration, etc. 

    After further reading (awesome instructable @McSTUFF, thnx) I've decided that to get the control and range of functions I want, I will have to make my own (plus... you know... making stuff like this is just plain fun).

    I'm going to run mine off 2x9v bats in series for an 18v (+-) base voltage and breadboard up the components so I can play with the design a bit:
    • Main power switch.
    • Variable resistor inline for adjusting output
    • 10mA fast blow fuse for safety
    • Touch switch and resistor + LED for battery check
    • Inline digital ammeter
    • Digital timer module with relay switch
    I'll add a touch switch to bypass the timer for adjusting and testing the electrode connectivity.

    So nothing fancy, no current regulator, I'm going to assume that good electrode placement will mean consistent resistance for 10-20mins sessions (yes I know the dangers of assumptions).

    I had considered adding a ohm meter with a mode switch as a way to test the electrode connection but for the time being I'll put in the switch and just use my multimeter.

    For electrodes I have wire, alligator clips, metal plate, and I'll 3d print something up to hold 5cm x 5cm x 1cm square of cellulose based sponge. 

    I need to mix up some saline but that should be the simplest part.

    About $30 (Au) so far in parts (thankyou ebay), the most expensive being the digital volt/ammeter (what can I say... digital readouts make everything look cool).

    If all goes well I'll post pictures/notes somewhere.

    However I'm still looking for design suggestions, I make/hack my own electronics but I'm more software than hardware so always open to advice.
  • McSTUFFMcSTUFF June 2016
    @Dr_Allcome, how do you plan to regulate amperage? Relying on skin resistance isn't safe or reliable. Variable current regulators are inexpensive and easy to hook up.
    http://www.digikey.com/product-search/en?keywords=LM334ZNS%2FNOPB-ND
    The LM334 is pretty easy to find on eBay too.
  • Dr_AllcomeDr_Allcome June 2016
    Awesome @McSTUFF , exactly the kind of advice I was looking to get!
  • gravatorgravator June 2016
    I have used the following write up to make mine and it works great. Plus a great and easy write up.

    2mA adjustable
    http://www.makeuseof.com/tag/build-tdcs-brain-stimulator/
  • Dr_AllcomeDr_Allcome July 2016
    My components are slowly arriving (ebay is cheap but slow) so I'm taking the time to add to my research about the various montages and what I want to try.
  • autumnautumn July 2016
    @McSTUFF Sorry, this is going to sound sarcastic, but I'm being entirely genuine. Is there a functional reason that you're doing a low-heat flame solder in your guides instead of using an iron?
  • McSTUFFMcSTUFF July 2016
    @Autumn, that doesn't sound sarcastic at all and there's a good reason. This Instructable was written for a workshop where we would provide all the tools and let people keep them at the end. It was an exercise in itself to create a soldering project which could be done by people without soldering experience and cost a minimal amount. There's absolutely no reason anyone couldn't use the same schematics and a soldering iron.
  • autumnautumn July 2016
    Oh neat! Love the DIY angle of it, never honestly considered being able to do kind of a survivalist solder joint with a lighter before.