Electropsychometer - Help understanding Circuit

Discussion in 'The Projects Forum' started by sms343, Aug 24, 2016.

  1. sms343

    Thread Starter New Member

    Aug 24, 2016
    Hello All,

    Very glad to find this site. Currently, Im conducting a research on Scientology and his famous Electropsicometer. A guy, had provided some schematics and due I'm not a electronic guy (Im a software engineer & psychologist), Im having a hard time trying to remember electronics I learned in college. First some overview on the e-meter (electropsicometer):

    This is a device that has 2 "cans" (electrodes) which is hold in hands by the person that is been audited (an auditor ask questions and the person responds). Think as a lie detector holding these 2 cans, one in each hand. As my basic understand, the person acts as a resistance and so the meters movement "reads" this difference in current when the auditor ask questions.

    Some questions about the circuit:

    1. What TA means? (There is 4 TAs)
    2. I will use 2 meter movements. Are they connected in the MAs? (There is 2 MAs)
    3. PC means pre-clear for sure (scientology term) so i guess where it says PC, it is the 2 cans connections.
    4. Where are the meter movements plugged?
    3. The rest is easy, just some op amps, diodes, resistors and capacitors but any detail I could be missing is very welcomed.

    Also some instructions from the website I took it:
    The diodes are any silicon signal diode. The LM385 should be a 1.26 volt low power version.
    The circuit is powered by 3 AA or AAA cells giving 4.5 volts.
    The circuit can be used for 1 or 2 meter movements. If one just uses 1 meter then TR2 is omitted and the high end of the TA pot goes to the point marked TA3. For a dual dial meter a multiturn pot can be used. If a 3 turn pot is available then connect the high end to TA3. If only 10 turn is available then try TA3 and TA4 to see which works best for you.
    The TA pot should be 20k wirewound such as Bourns 3590S-2-203 and the sensitivity pot 50k.
    For normal use with 2 cans SW2 can be shorted. If one wants automatic retrimming for solo cans or fingertip electrodes then switch in values of 22k and 39k respectively.


    1. Adjust the mechanical zero of the TA meter to 1/20th division below zero. I.E. 0.95 TA.
    2. Adjust TR2 so that the TA meter reads 6.5 with no connection to the meter.
    3. Connect a 12.5K resistor and adjust TR1 so the the TA meter reads 3.0
    4. Short circuit the PC input and adjust TR3 so that the needle is on the dial with the TA pot all the way anti-clockwise.

    Please find attached the schematic. The URL where i took it: https://www.cs.cmu.edu/~dst/E-Meter/Ralph_Hilton/Mk4.htm

    I will appreciate any help with this.


    Mod edit: Title
    Last edited by a moderator: Aug 24, 2016
  2. wayneh


    Sep 9, 2010
    You should edit the title of your thread to spell electropsychometer properly.

    I couldn't find any reference describing what "TA" stands for. It may just be gobbledygook to make things sound more complex than they are.

    Since the device doesn't really do anything, I'm not sure how important the circuit details are. ;)
  3. hp1729

    Well-Known Member

    Nov 23, 2015
    Having browsed L. Rom Hubbard's modified dictionary he redefines things so it makes his "theories" appear to work. The circuit does show a human response but it does not necessarily prove any meaningful result. Yes psychotherapy CAN be useful for improving your outlook on life, aka "Clear"., but it proves far less that Hubbard claims.
    If it works for you, good for you. Stay with Scientology. I think it won't do any more harm to your psyche than any other religion. Nor will it benefit you any more.
    #12 likes this.
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
  5. #12


    Nov 30, 2010
    This reminds me of an HHO device I looked at for a physician who wanted to build one. It had a divide by 17 circuit in the main clock just so it would involve a "mysterious" prime number.:D
  6. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
    For it to do anything at all, TA2 must be connected to something. TA1 would be a sensible place. Why they didn't just draw a wire between these I don't know.

    SENS1 must be connected to either SENS2 or SENS3 (changes the sensitivity).