2014-10-05 (Su) tDCS Unit

The panel mount milliammeter required a 1 7/8" (48mm) hole for the unit to mount flush. A 1 15/16" (49mm) Forstner drill bit was the closest available size. A test hole was drilled into a scrap of wood then two 5/32" (4mm) holes were drilled for the mounting bolts. When a good fit was determined a 1 15/16" (49mm) hole was drilled into the project enclosure 6" x 3" x 2" (152.4mm x 76.2mm x 50.8mm) (Radio Shack part # 270-1805)  on a lengthwise center line through the top panel. The scrap wood template was placed on top and the bolt holes were marked and drilled to 5/32". 1/8" (3mm) holes might have been large enough.

 Measuring the diameter of the hole and the drill bit

Marked hole sizes in the scrap wood template

Panel mount milliammeter in the scrap wood template

The top of the enclosure had spots marked every 3/8" (9.525mm) which were pilot-holed. The holes intended to hold the terminal blocks in place were drilled to 5/32" (4mm) while the holes for the terminations themselves were drilled to 9/32" (7.2mm). 1/4" (6.5mm) holes were drilled above the locations of the terminal blocks for the 1/8" (3.5mm) phone sockets.

 Large hole drilled in enclosure

Pilot holes drilled for terminal blocks

Holes drilled for inputs and outputs

The socket and terminals on the left side were intended to serve as the input while the socket and terminals on the right side were intended to serve as the output. The cathode ends were all connected together. The anode ends of the inputs were connected together at the input of the milliammeter. The anode of ends of the outputs were connected together at the output of the milliammeter. This interconnection allowed the testing unit unit to serve as a converter box so leads or a phone jack could connect to the input while the other method could be used on the output while monitoring the amperage.

Internal wiring. Schematic soon

A label was made for the front of the testing unit. Colored marker was used on a PSA label then laminated with clear plastic tape and trimmed to size. A rotating shot was taken using the Rotational Photography Rig.

Not bad looking, eh?

The green platform is actually my upside-down office garbage bin

To do:

  • Sketch testing circuit
  • Buy + Install #8 Nuts + Bolts
  • Test with mental aptitude test

 Journal Page 1

Journal Page 2


The rest of the posts for this project have been arranged by date.

A list showing of all the final posts of COMPLETED projects.


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