Re: Hello Listers
My comments are interspread below:
Dia. 1.5 in Frequency: 3692.62 KHz
Length of Winding:14 in 1/4 wave: 66.64 ft
18 AWG ----------
Inductance: .39 mH Freq: 2117.44 KHz
Self Cap: 4.73 pf W/Top Load Cap: 9.65 pf
Length of Wire: 125.71 ft 1/4 wave: 116.21 ft
Total Turns: 320
The AWG 18 wire is way too big for your coil (which is why your FRes is in the
Mhz range) My 8" coil only uses AWG 19.5 (metric equivilent). For a 1.5"
diameter coil you will want an AWG 27-30. This will give you a more reasonable
amount of turns for your former diameter. 320 turns would be okay for a
magnifier driver, but not for your spark gap driven "normal" tesla coil. Your
inductance of 0.39 mH (?) is too low.
For a nice spark length you might want to go for an FRes of about 500kHz
(unloaded coil). With the proper top load you can drop the FRes (loaded) to
about 300 kHz.
My Primary is pretty crummy, in its accuracy as well as looks. These are the
best approximations I could make. If you could give us an Idea how you do it,
we'd be thankful.
Inside Dia.: 4.65 SecondaryFreq.: 2117.4377
8 AWG Required Cap: .0006
Spacing(average): .875 in Total Dia: 13.44
Total turns: 6 Length of wire: 14.21
You will want more turns on your primary coil and for AWG 8 (which would be
okay for your coil) you donīt need a T-T (turn to turn) spacing of 7/8". I
usually go for an even spacing. This means is the wire size (e.g.) is 3/8"
then go for a 3/8" T-T spacing.
Transformer Input: 120 v 60 hz
Transformer Output: 3 kV .85 mA
Capacitor Match: .0008 uF
Oops. I hope you mean 85mA (not 0.85mA). If your xformer really only gives you
less than 1 mA, forget about using it. Secondly, like I said before 3kV is on
the very low side. It is very difficult to build a spark gap (esp. if it is a
multiple element gap) that will work properly at 3kV. Go for at least a 6kV
xformer. If you can get a second one of these xformers (and if they are not
center tapped) you can series the secondaries like this:
a T1 b c T2 d
a and d are your new output (6kV). The connection between b and c is grounded.
As you are grounding the new "center tap", each xformer never sees more than
its allowed rated 3kV above ground. However, this will ONLY WORK if the
xformers DONīT already have a center tap.
Type: Bottle Transformer, got plans from Bill Beaty's Web page
capacitance: still to be tested
Bottle Xformer? I guess you mean SW caps? They will be okay for your setup.
Just make sure you match C & Lpri for resonance at the secondaries FRes.
Type: Toroid Height: 2.38 in
Outside Diameter: 6.31in Capacitance: 9.65pF
Inside Diameter: 2.4375 in
Hmm, above you say Ctop+Cself is 9.65pf. Here you state that Ctop itself is
9.65 pf. Which holds true? Toroid capacitance should be somewhere between
0.8*Cself and 5 * Cself. The bigger the coil and the bigger the input (cap and
all) the bigger youīll want your toroid to be. With your coil I would go for
about 1-2 Cself.
Questions: What is a PFC rating?
PFC means Power Factor Correction. Where did you find this? If this is written
in conjunction with your xformerīs input amps, it simply means the xformer
will pull the printed amps only if it is power factor corrected (with a
capacitor). As the current lags behind the voltage the cap stores part of the
energy and gives it back to the transformer at the right time (and turns
otherwise wasted energy into usable energy. This means you actually increase
the output of your xformer with a PFC cap connected across the primary.
Coiler greets from germany,