Re: Strange events and me coil unexplained
In a message dated 12/16/98 7:15:25 PM Pacific Standard Time, tesla-at-pupman-dot-com
<< Hey everyone,
Last night I ran my 6.5" coil at approximatly 5 Kw. 14.4 Kv. My air
choaks melted. They were wound with 18 AWG insulated wire. Even the PVC
core melted and twisted. How is this possible, there should only be
millamps on the HV side ? My capacitance has also increased. I made
these caps over a year ago. Each cap is .026 uf. I have 4 in the
circuit, two each in parallel and then these two circuits are in series.
Ordinarly I'm taped out with the large top load at the 13 th. or 14th.
turn. Last night I had to tap in to the 9th. turn ! A few weeks ago I
move the coil outside and noticed that I had to tap in. I attributed
this to ground clutter. Could the caps still be setteling ?
The calculated value of these caps were .026 uf. They had a measured
value of about .024 uf. They are poly plate caps. Does anyone have
anyone have any ideas about the RF choaks or the the caps ?
Something funny is going on here. Your coil and mine are similar in size and
I ran some quick calculations. I don't know the size of your toroid so I
plugged in 40 pf arbitrarily. With the primary tapped at turn 13, a
capacitance of .018 ufd is required for resonance. With the primary tapped at
turn 9, .041 ufd is required. This is a change of over 100% in capacitance
value. Maybe there is a connection problem with the caps and one becomes open
or shorted?? Does the secondary have a good ground?
About the RF chokes, you are right, the wire size says they should be fine.
Possibly an unwanted resonance problem? At the advice of Bill Wysock, I have
removed all protection caps, resistors and chokes between the H.V.
distribution transformer outputs and the tank circuit. None of it is
necessary to protect the transformer.