Tesla Coil Build Thread

[Sigurthr]

Oh, and based on this chart, Capacitor uF - nF - pF Conversion Chart, and Deepfriedneon, the transformer I link would need 15nf capacitors.

You missed where I said earlier that when using a static (non-moving) gap you need to multiply the capacitance by 1.618 (phi) for proper operation. You can get away without doing this, but you suffer a small performance hit and risk blowing up your NST and capacitor (even with a terry filter).

 

[The Lightning Stalker]

PVC makes a pretty crummy dielectric. The
advantage of using water is the built-in
cooling. The disadvantages are safety and
it rots the wiring.

Back in the days before the MMC, Richard
Quick was building roll caps out of
polyethylene house wrap and aluminum roof
flashing.

 

[Sigurthr]

Yeah, PVC is pretty lossy at RF. But it beats wood!

 

[USAbro]

Just was wondering guys, would it work it I wired two or three 2kv lamp ballasts in series and then put a diode on one of the leads, and wired it to a very small TC. Would it still be too high frequency even though it would be pulsed dc.

Also, can a spark plug ignition coil drive a TC and if so, can a ballast drive an ignition coil?

Also, can lower voltage diodes be wired in series to add up to the voltage you are using.

For example, if I wired three 2kv lamp ballasts in series, making 6kv, and I had 500v diodes, could I use 12 diodes in series to convert the AC into pulsed DC? Also, would 500v diodes work for 15khz?

 

[Sigurthr]

Just was wondering guys, would it work it I wired two or three 2kv lamp ballasts in series and then put a diode on one of the leads, and wired it to a very small TC. Would it still be too high frequency even though it would be pulsed dc.

You cannot wire them in series without destroying them. They aren't simple devices like magnetic ballasts or transformers. You can wire simple transformers in series, but only in a handful of special configurations. See earlier in this thread about series connecting MOTs.

Also, can a spark plug ignition coil drive a TC and if so, can a ballast drive an ignition coil?

An Ignition Coil can certainly drive a TC, but no you can't power it with a ballast (not the type you are using anyway). Ignition coils run on 10-60Hz, with an input voltage of 10-100V, at several amps.

Also, can lower voltage diodes be wired in series to add up to the voltage you are using.

Yup, diodes work this way. The entire string of them only retains the current rating of a single diode, so if you have ten 1amp diodes in series, the whole thing can only handle 1amp even though it can handle 10x the voltage.

For example, if I wired three 2kv lamp ballasts in series, making 6kv, and I had 500v diodes, could I use 12 diodes in series to convert the AC into pulsed DC? Also, would 500v diodes work for 15khz?

Whole bunch of nopes. Also, anything over about 8KHz requires diodes marked as "fast".

 

[USAbro]

So can a simple 24vac power a ignition coil?

 

[Sigurthr]

So can a simple 24vac power a ignition coil?

Depends on the current available, but yes. 24V at 5A or so, sounds about right. The ignition coil can look like a short to loads only rated for low current (<1A).

 

[USAbro]

So is it two wires in and two wires out and regular 60htz in?

 

[Sigurthr]

It may be terminals and not wires, but, yes.

Just like a NST, just different input requirements. I'm curious though where you've got a 24VAC ~5A supply from though. Would be a bulky transformer or variac.

 

[nospin]

I finished the secondary today

just needed to trim the end bolts to length

first time seeing it where it belongs

 

[Sigurthr]

Looks great!, Nospin. Can't wait to see it running!

 

[Down with Umbrella]

hey Nospin that secondary looks great! I wish mine looked as good.

Ehh, I ordered 1.6lbs of 24awg magnet wire. According to my calculations I should have had enough for exactly 22inches of winding.(my target was closer to 23in 950-1000 turns)
however after I wound ALL the wire off the spool I ended up with 903 turns. EXACTLY 21 inches. I should have ordered more wire and done my calculations different. lesson learned

So is this a big problem? aside from affecting my 5:1 ratio. if I have a shorter secondary I need to have a tap point closer to 8-9 turns instead of 10-11.
correct me if I am wrong but to maintain a correct ratio I need to decrease the size of my top load to reduce the tap point turns on my primary.
since it is already built I guess im going to just give it a try. its current status is finished and the polyurethane is drying.
any ideas?
(photo is during my winding process)

 

[Sigurthr]

Don't worry a bout h:w ratios, as long as you're in the ballpark it works fine. The notion of a perfect ratio was disproven along with the need for halfwave wire length a few years ago.

 

[Down with Umbrella]

I'll test it out to see how it goes. I do think I'll have to lower my strike ring. It might be positioned too close to the top load.

 

[USAbro]

It may be terminals and not wires, but, yes.

Just like a NST, just different input requirements. I'm curious though where you've got a 24VAC ~5A supply from though. Would be a bulky transformer or variac.

Variac.

 

[nospin]

I think it looks great!

Sigurthr is right, Your 900 turns is right on target, thats what I shoot for,
this photo showed me I had 962 turns, more than I wanted, but still in the 800 to 1000 window, Good work!

little tuning and all will be mute!