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.
Calibration:
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.
Thanks!
Mod edit: Title
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.
Calibration:
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.
Thanks!
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