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Subject FAQ: Neon transformer wi=
ring diagram - demo fusor
Posted by Richard Hull on 2004-02-03 10:38
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Attached is a diagram on the power supply wiring for a DEMO type fusor u=
sing a neon transformer. This supply WILL NOT supply the voltage or pow=
er needed to make a deuterium fusing fusor.
All neon transfor=
mers over 7.5 KV are CENTER TAPPED SECONDARY types. This connection is =
carried out to the METAL CASE BODY and is the return path for the two ou=
tside HV knobs. It is always GROUNDED! The knobs, then, relative to gr=
ound, are at 1/2 of the rated potential of the transformer.
A=
s shown, the output would be on the order of 8kv max with no load. With=
a 2ufd @ 10kv capacitor, you might expect 7kv @5ma with the voltage low=
er at higher plasma loadings.
NOTE***** With a capacitor, th=
is circuit is especially lethal and can kill instantly. Be very careful=
to discharge the capacitor before working on the circuit. Without the =
capacitor the circuit can still kill in certain circumstances, but at mi=
nimum it can injure you severely and make you wish you were never born.<=
br /> The digital panel meters are cheap and can be found from a nu=
mber of electronic suppliers like Jameco, Marlin P. Jones, etc., for abo=
ut $10.00 to $20.00 each. You will need to set the decimal point using =
the instructions supplied with your meter.
The critical 100 m=
egohm series resistor is a special high voltage resistor (DO NOT USE 10=
- 10 megohm common resistors in series!!!! This resistor must withstan=
d the full voltage; common resistors will not! The proper resistor wil=
l be a long resistor, (~3" long), designed to prevent arc over
NOTE****
It is very important to use a variac or varia=
ble transformer to supply a variable 0-120 volts AC input to the transfo=
rmer's primary. This will allow a smoothly variable output DC volta=
ge to the fusor ranging from 0 volts to almost 8 kilovolts.
I=
t is also very important that all current metering is done with a low va=
lue high wattage SHUNT resistor in the circuit!!!! This is regardless o=
f whether you use an analog or digital meter. NOTE!! The grounding of t=
he transformer case is achieved through the current shunt resistor! If =
you ground the case directly, the current meter will not work.
All the grounds shown should be connected together with the shortest p=
ossible routing and this single connection taken via a short, fat cablin=
g to the fusor chamber body and attached at the same bolt or point on th=
e fusor chamber that your real, super earthed, electrical ground is conn=
ected to. (star grounding)
Richard Hull | <=
/TR>
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Subject Re: FAQ: Neon transforme=
r wiring diagram - demo fusor
Posted by Henry Cross on 2011-06-08 12:43
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Hi Richard,
Is it worth using GFCI outlet or will the transfo=
rmer disconnect the circuit sufficiently?
Thanks, Henry =
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Subject Re: FAQ: Neon transforme=
r wiring diagram - demo fusor
Posted by Carl Willis on 2011-06-08 14:39
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Henry,
If you observe proper wiring practices, the GFCI shoul=
d cause you no trouble.
-Carl |
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Subject Re: FAQ: Neon transforme=
r wiring diagram - demo fusor
Posted by Wallace, Allen on 2011-06-08 21:37
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Richard,
I know that you are trying to keep the schematic sim=
ple and theoretical but perhaps we might add a diode across the voltage=
meter. If the 100M resistor arcs over, then the diode will protect the =
panel meter which is typically exposed to the the operator.
=
Its possible that someone will use common resistors which typically have=
a max voltage to 150 Volts. A possible but misguided design might use t=
en 10M resistors in series and these will arc over. Perhaps you could cl=
arify the requirements of the 100M resistor.
Allen Wallace
Edit: I have added a note about the need for a special HV resi=
stor in my original. RH |
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