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Measuring TC Secondary Voltage
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From: John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
Sent: Tuesday, February 17, 1998 2:01 AM
To: Tesla List
Subject: Measuring TC Secondary Voltage
To All -
The TC sec voltage cannot be measured by connecting instrumentation to the
sec term because this reduces the voltage by an unknown amount. This means
that voltage dividers are out.
There is a simple test that coilers may want to try. Several years ago I
tried this test with the following results. The electric field around an
operating TC can be tested by a probe in the field. I used a Morris and Lee
7 inch oblate (10 pf) This oblate will collect coulombs according to the
following equations
Q = C x V = I x t
Q = coulombs C = farads V = volts
I = amperes T = seconds
The oblate is connected to a 1000 ohm resistor. The other term of the
resistor is connected to the same ground as the TC. A 0 - 300 microvolt hi
-impedance meter is connected across the resistor. My tests and calcs give
the following table
Watt KV FT ua uv
40 100 2.5 .25 250
900 500 5.0 .20 200
3000 1000 10.0 .10 100
Watts = input watts
KV = kilovolts at sec term
FT = oblate distance in ft from TC sec term
ua = microamps
uv = microvolts
This test is speculative but is easy to implement so you may want to give
it a try. Anyone with a 40 watt to 3000 watt coil can try the test.
Comments welcomed
John Couture