UK coilers ? + stuff (fwd)
---------- Forwarded message ----------
Date: Fri, 31 Jul 1998 18:37:50 +0100
From: "chris.swinson" <chris.swinson-at-zetnet.co.uk>
Subject: UK coilers ? + stuff
I've just joined the list to help and swap ideas with more experienced
First of all are there any people in the UK ? I live in Uttoxeter (
Staffordshire , Near Burton on Trent ). Any one live near me ?
I haven't built a large coil, mine is only a 240 watter. I can get up to
9" sparks off my coil. Has anyone built a 240 watt coil and got bigger
sparks than that ?
My first question.... My secondarys resistance is about 77R, Does anyone
know how much resistance I can actually get away with. I'm just builing a
200R coil just to see what happens.
Has anyone tried a DC transistor driver, My high voltage input it a small
8Kv -at- 30ma, thats 240 watts. If I used 160 volts at about 2A that would
give about the same wattage. But would this work as well as the high
voltage ? I know that the cap and spark gap would not be needed as the
transistors would have to switch to about 600Khz anyway. As far as I can
tell this would work better and the coil should run a lot smoother, Any
thoughts any one ? ?
I also don't 100% understand when people say build coils with a 3:1 ratio,
can anyone enlighten me ? The ratio for my coil as I see it is 1:260 so
where do you all get 3:1 from ?
Accroding to my secondary inductance calculations my coil is about 39 mH,
But actaul measurement shows 7.4mH. Does anyone know is this reduction in
inducatance is good ? As far as I see it , it is but as far as I can see
it may increase capacitance which is bad. Oh, I varnished my coil so
thats why it's different. I was thinking of doing 2 coils the same, but
laqureing one to compair results, But can anyone tell me whats what before
I send the time doing more coils ?
Whats the output current of a coil ? I know the capacitor may well give a
very small peek of up to 1000's of amps, But the current rating of the
wire in my secondary is about 140 ma, Does this mean I can only draw 140ma
or is there something else to it all.
Has anyone tried a magnet as a discharge terminal. I used a old speaker
magnet ( donut ) and I get evenly spaced sparks off it, about every inch
around the magnet. This is rather interestinf to me, Anyone tried this
know why it does that ?
Has anyone got any thoughts on using a valve as a spark gap, I used a
small ECC88 ( I think) there was 2 plate inside which were close enough
for the spark to jump, note that I only used the valuve not heaters or
anything else at all. My coil ran very well indeed. It was a lot
smoother and the performance was a lot better. But it got a tad hot ans
exploded so I decided that I ought to find out more about it if I can.
Anyone help ?
Thats it, Thanks to all who have stayed tuned :-))
All the beST,