Test Plates Assembly

Test Plates Assembly

Cut two 3-1/2 inch squares out of stiff paper such as a milk
carton. Cover them with 4½ inch squares of aluminum foil,
smoothed evenly and tucked snugly under the edges. You have
just made yourself a set of open capacitors. Turn the box upside
down and draw squares where you will mount them at the ends of
the box. Don't actually mount them, to save wear and tear on
them, until the rest of the box is complete.
Mount the ON OFF switch on the front of the box, underneath
the right hand plate. Line it up so ON is downward and OFF is
up. (An electronics shop can determine this for you at the time of
purchase.) Label the box with ON and OFF signs.
Two bolts will be reserved for the plates. The third bolt is
used as a terminal where the current from the oscillator circuit
will arrive. Make a hole on the side of the box, near the left hand
plate and mount the bolt so it sticks half way inside and halfway
outside the box. It does not matter whether the head is inside or
outside. Tighten it there with a nut on each side of the box. Label
it TERMINAL. It merely means connecting place.
Mark the center of each square that you drew and each capacitor
you built. Pierce first with a pin; follow with a pencil
until a round hole is made at the center. Mount each plate with a
bolt, fastening it below with a nut. Washers are optional.
The left side connection (terminal) gets attached to the left
plate (bolt) with an alligator clip. Use another clip to attach the
same left plate (bolt) to the ON OFF switch (there are two connections,
use either one). Finally attach the ON OFF switch
connection you didn't use to the right plate (bolt). Make sure the

connections at the switch are not touching each other; you might
tape them to guard against this.
All these connections should be checked carefully to make
sure they are not touching others accidentally. But if you leave
the box open so you can see any problems and use clear tape
around connections to prevent accidental touching to the wrong
connection, it should work OK.
Finally, trace your current. It comes in from the Syncrometer
at the main terminal on the left. It is brought to the left plate.
When the switch is ON it is simultaneously brought to the right
plate. Notice that the plates are not connected to anything else.
They are simply capacitors, letting current in and out momentarily
and at a rate that is set by the frequency of the oscillator
circuit, about 1,000 hertz. This frequency goes up as the resistance
(of the circuit or your body) goes down.
The probe and handhold allow you to include yourself in the
Syncrometer circuit. You grasp these when testing. This makes
you part of the circuit.
The speaker lets you “listen” to the current. As resistance
drops, current goes higher and frequency goes up. As frequencies
go higher in the circuit, pitch goes higher. You will be comparing
the sound of a standard “control” current with a test current.