Tesla Coil Project - Need Help Please

[DerStrom8]

So its late over there? Only lunchtime here

I think I may make them all at the same time and then decide if I have too many / not enough. I've taken a picture of my multimeter. After I build them, how shall I measure them all? I haven't really done this before so just needing to know haha.

https://imgur.com/a/BO8LZ

Thanks,
Marco

Okay, good afternoon, Marco Coming up on 6 pm here in Boston.

Your meter does not measure capacitance. It's only a basic model.

If you can get your hands on a capacitance meter, then connect the caps in parallel (All the tops connected together and all the bottoms connected together) and to measure it put the meter probes between them.

Good luck!
Matt

 

[marcopolo09190]

Okay, good afternoon, Marco Coming up on 6 pm here in Boston.

Your meter does not measure capacitance. It's only a basic model.

If you can get your hands on a capacitance meter, then connect the caps in parallel (All the tops connected together and all the bottoms connected together) and to measure it put the meter probes between them.

Good luck!
Matt

Good evening then Matt Cool Boston! Your far away from where I am haha.

Hmm now I need to search for a meter that measures capacitance too /: I wonder where I'll find that lol.

Thanks
Marco

 

[DerStrom8]

Good evening then Matt Cool Boston! Your far away from where I am haha.

Hmm now I need to search for a meter that measures capacitance too /: I wonder where I'll find that lol.

Thanks
Marco

Haha, yes, you said you're in Australia? Or was it New Zealand?

Not sure what kinds of retail stores you have way down there, but I bought my Craftsman from Kmart for $35 USD. The price has dropped to $25 though (I'll leave the currency conversions for you ).

This is the one I have:

View attachment 68650

It's lasted me a good 6 or 7 years, on just a single battery at that. I highly recommend it, if it's available.

Best wishes,
Matt

 

[marcopolo09190]

Haha, yes, you said you're in Australia? Or was it New Zealand?

Not sure what kinds of retail stores you have way down there, but I bought my Craftsman from Kmart for $35 USD. The price has dropped to $25 though (I'll leave the currency conversions for you ).

This is the one I have:

View attachment 68650

It's lasted me a good 6 or 7 years, on just a single battery at that. I highly recommend it, if it's available.

Best wishes,
Matt

How dare you mistake New Zealand for Australia! haha

I'll be on the lookout for that I just went to the shops and bought all this:

View attachment 68651

Now all I have to do is find some beer bottles of the same size, build them, and find a meter like yours

Thanks,
Marco

 

[DerStrom8]

How dare you mistake New Zealand for Australia! haha

I'll be on the lookout for that I just went to the shops and bought all this:

View attachment 68651

Now all I have to do is find some beer bottles of the same size, build them, and find a meter like yours

Thanks,
Marco

I'm sorry, I have a few different members here mixed up

 

[marcopolo09190]

I'm sorry, I have a few different members here mixed up

Haha do you know anyone else from New Zealand on here? and do all those parts look good?

Thanks,
Marco

(Brb doing washing so might not respond straight away)

 

[DerStrom8]

Haha do you know anyone else from New Zealand on here? and do all those parts look good?

Thanks,
Marco

(Brb doing washing so might not respond straight away)

ElectroMaster, the site administrator, is from Christchurch, New Zealand. He moved to Australia after the earthquake.

The parts look pretty good, by the way. Let me know when they're all put together and we'll go from there

Regards

 

[marcopolo09190]

ElectroMaster, the site administrator, is from Christchurch, New Zealand. He moved to Australia after the earthquake.

The parts look pretty good, by the way. Let me know when they're all put together and we'll go from there

Regards

Oh cool Yeah that earthquake hit bad.

Sweet, yeah all I have to do is get 12 bottles and caps

Are you doing any project at the moment by the way?

Thanks,
Marco

 

[DerStrom8]

Oh cool Yeah that earthquake hit bad.

Sweet, yeah all I have to do is get 12 bottles and caps

Are you doing any project at the moment by the way?

Thanks,
Marco

I unfortunately have not had much time lately for projects. I've been especially busy at work and just haven't had any free time.

 

[marcopolo09190]

I unfortunately have not had much time lately for projects. I've been especially busy at work and just haven't had any free time.

Oh a shame /: what do you do for work if you don't mind me asking

Marco.

 

[DerStrom8]

Oh a shame /: what do you do for work if you don't mind me asking

Marco.

I'm currently employed as a lab assistant in the electronics/computer engineering laboratory at a university here in Boston. I'm looking into a possible steadier job, though. We'll see what happens

 

[shortbus=]

Don't mean to butt in , but, have you guy's ever used BB gun BBs for the inner capacitor plates of your bottle caps?
They do two things that the liquid/salt doesn't. They add some weight to the base of the coil to make it more stable. And they don't give a chance to the start of corrosion like the salt can.

Also in the books I've seen, they said that beer bottles weren't as good as clear bottles for the capacitors. But that was back in the 1970s and things/thinking may have changed.

Thank you both for this thread.

 

[DerStrom8]

Don't mean to butt in , but, have you guy's ever used BB gun BBs for the inner capacitor plates of your bottle caps?
They do two things that the liquid/salt doesn't. They add some weight to the base of the coil to make it more stable. And they don't give a chance to the start of corrosion like the salt can.

Also in the books I've seen, they said that beer bottles weren't as good as clear bottles for the capacitors. But that was back in the 1970s and things/thinking may have changed.

Thank you both for this thread.

Not a problem shortbus. Thanks for the input.

I've never heard of using BBs for the inner plate. I assume you mean filling the bottle completely up with BBs? I would have never done that because of all the "bumpy" edges inside. I'd assume they could lead to unwanted arcing.

Clear bottles will probably work best because some of the chemicals in the paint (or other sort of coloring) could be somewhat conductive. This would lower the voltage tolerance of the capacitor and change the total capacitance, compared to clear ones. However, I don't feel the coloring makes enough of a difference for it to be a problem.

Marco, I keep forgetting to mention--when you build beer bottle capacitors, you MUST have some sort of vent hole in the top to allow heated gases to escape. If you don't, it could build up pressure and potentially explode, sending shards of glass and hot oil all over the place (worst case scenario). Just make sure you poke a hole in the screw-top of each bottle to allow the pressure to be released before building.

Regards,
Matt

 

[shortbus=]

DerStrom, you only fill the BB's up to the level of the foil you put on the outside. Never seen any arcing, the weight of the BB's keeps them in good contact with each other. Plus since there's only one pole of the circuit on them what would cause arcing?

Another dumb question/thought. Using oil for the liquid, how does the salt get dissolved into it? Never seen salt in oil do anything but suspend for a time, then go to the bottom of the container.

 

[DerStrom8]

DerStrom, you only fill the BB's up to the level of the foil you put on the outside. Never seen any arcing, the weight of the BB's keeps them in good contact with each other. Plus since there's only one pole of the circuit on them what would cause arcing?

Right, that's what I meant. And I was talking about arcing, or at least corona leakage, between the BBs and the foil. Rough edges make it easier for charge to leak though the glass. Guess it probably wouldn't be much of a problem for voltages only around 15kv though....

Another dumb question/thought. Using oil for the liquid, how does the salt get dissolved into it? Never seen salt in oil do anything but suspend for a time, then go to the bottom of the container.

The oil isn't used for the liquid. Water is used, but oil is put on top to prevent corona leakage around the surface of the water. It's only a thin layer, perhaps 3/8" to 1/2" deep. And since oil is less dense than water, it floats on top. Helps keep everything well-contained.


By the way, Marco, make sure you put the wires/screws in the bottles BEFORE putting in the oil. This is very important. Otherwise the oil will adhere to the screws and make for very poor conduction. Just another small thing I learned from experience that makes a huge difference.

Regards

 

[marcopolo09190]

Hiya Matt!

I've built the capacitors and they look amazing! They also work amazing and with 12 I get 9nF!

I borrowed a multimeter from school to use:

View attachment 68746

I've done a little list of all the capacitance's for each bottle and this is it:
0.79nF
0.78nF
0.73nF
0.74nF
0.76nF
0.79nF
0.76nF
0.72nF
0.75nF
0.74nF
0.75nF
0.77nF

Total = 9.08nF

Here's a couple pictures:

View attachment 68741

View attachment 68742

View attachment 68743

View attachment 68744

View attachment 68745

As you can see I didn't use caps but rather made my own wooden corks, they aren't completely round so there's some gaps for pressure to vent.

Whoops I didn't see your message about putting the bolts in before the oil. I'll give the bolts a little wiggle just to get any oil off.

What do you think I'm gonna make a little case to put them all in with the floor being aluminium foil and how shall I wire up the top? Could you draw it on top of one of the pictures if you want? That'd make it easy for me.

Also Matt, I'm just wondering if it's only the Solid State Tesla Coils that can be used to make music with or can I also make music with a Spark Gap Tesla Coil?

Thanks and can't wait to see your reply!
Marco

 

[DerStrom8]

Hey Marco. Those are some very well-built capacitors--0.75~ nF from a single bottle is excellent. It sounds like you could do fine with only 8 of them, in that case. You can keep the extras on-hand as backups

I'm afraid wiggling the bolts won't help. They have to be very clean in order to work. I hate to say it, but you might have to dump everything out, clean the bolts, put them in, and then put in the water and oil. Before you do, though, go ahead and test it the way it is now (minus 4 bottles). It might work anyway.

Now that the capacitors are done, I think it's probably about time to hook them up to the rest of the setup. I would use the configuration with the spark gap in parallel with the transformer and capacitor in series with the output. This helps protect the transformer in case of large voltage and current spikes.

I look forward to seeing your progress!
Best wishes,
Matt

 

[()blivion]

I'm not 100% on this, but you could pull the bolts out, wash them in mild to medium concentration dish soap and water, DON'T rinse them, then put them back in. Dish soap acts as a surfactant, and should (in theory) thin/repel the oil when inserting the bolt. Then when it enters the water, it dissolves into it and removes any oil that managed to get on the surface. My only worry's would be that with the water being saturated with salt it may not allow the soap to dissolve away from the bolt (soap is a salt of fatty acids). And that the soap may attack the oil, lowering it's insulating properties ruining it.

And of course, it may not remove the oil at all

Great thread BTW.

 

[marcopolo09190]

Hey Marco. Those are some very well-built capacitors--0.75~ nF from a single bottle is excellent. It sounds like you could do fine with only 8 of them, in that case. You can keep the extras on-hand as backups

I'm afraid wiggling the bolts won't help. They have to be very clean in order to work. I hate to say it, but you might have to dump everything out, clean the bolts, put them in, and then put in the water and oil. Before you do, though, go ahead and test it the way it is now (minus 4 bottles). It might work anyway.

Now that the capacitors are done, I think it's probably about time to hook them up to the rest of the setup. I would use the configuration with the spark gap in parallel with the transformer and capacitor in series with the output. This helps protect the transformer in case of large voltage and current spikes.

I look forward to seeing your progress!
Best wishes,
Matt

Thats great They do feel well built and I feel really proud of them :3

Yeah I'll test it the way it is and then if that doesn't work, I'll get some more oil and salt.

For that configuration, is this what you meant?

View attachment 68758

I look forward too!

BTW, you didn't answer this question I had "Also Matt, I'm just wondering if it's only the Solid State Tesla Coils that can be used to make music with or can I also make music with a Spark Gap Tesla Coil?"

Thanks
Marco

 

[DerStrom8]

Hi Marco.

That looks like the right configuration, yes. Here it is in schematic form:

View attachment 68760

Sorry, I forgot to answer your question. In order to make a musical Tesla coil, you'll really need some sort of solid state control to modulate the input. The output would also have to be directly tuned to the input, which is really only possible with a full solid-state circuit.

Regards,
Matt

EDIT: Oh, and DO NOT connect the secondary ground to the transformer ground. The transformer ground should be connected to mains ground, and the secondary should be earthed. Connect it to a metal stake (1-2 foot, 30cm-60cm) and pound it into the ground.