Low power Tesla coil build

[Alien 13]

I saw the recent post regarding a Jacobs ladder build and mentioned my interest in Tesla coils, now we are not talking of the fire breathing monsters but an alternative version powered by battery or 12V adapter.

My journey started with a cheap "toy" from Amazon that is actually very good at demonstrating the principles of Tesla coils..https://www.amazon.co.uk/JZK-DIY-Plasma-Speaker-Transmission/dp/B071DV9PZL/ref=sr_1_1?ie=UTF8&qid=1528145894&sr=8-1&keywords=tesla+coil+kit the actual drive circuitry is perfectly capable of running a bigger coil.

My circuit which is a Slayer/Exciter is based on the above design but it is probably cheaper to just buy the kit.

 

I used 0.315mm wire for my secondary with about 800 turns but you can experiment with whatever is at hand.

The critical thing with this design is getting the phasing between primary and secondaries correct and fine tuning of the coupling between the two by moving the primary winding until the oscillation starts (indicated by the LED from the transistor base to ground illuminating). My particular coil is running at between 40-60KHz depending on the top loading.

I have a couple of pictures of the finished coil in action as well as the mini toy.

It does look tiny but it can still bite so take precautions i.e. dont touch it when running.

This is the bigger one running a 60W florescent bulb, range is about 14 inches (the little one will do the same at about 4 inches). The other thing I should mention is that I am using a tiny transistor heatsink for now so it gets hot quick but is OK for a minute or two of operation.

Thanks for looking.

Alan

 

 

 

 

 

[MarsG76]

Very cool...

 

[teoria_del_big_bang]

Nice.

[Alien 13]

I have just started the build of a bigger Tesla coil, might have to double up the transistors to handle the extra current and heat though. The wider coil should change the resonant frequency i.e. lower so should be easier to drive.

This is the coil after a hard manual winding job.

Thanks again for looking.

Alan

 

[RayD]

Great stuff, Alan.  Really interesting.  I just watched a documentary on Tesla.

[Stu]

What a fun and interesting project! Looking forward to the results from big brother!

I don’t know a lot about them so will do a bit of reading up.

[Alien 13]

I have finally completed the initial build of the larger Tesla coil, I am still using the single transistor circuit but with a much better heatsink, my poor woodwork skills and inability to drill round holes in the right place has meant this project has taken a lot of effort.

I was surprised that it fired up up first time, it is a lot less finicky than its smaller brother but does not output as much power yet although fine tuning and a new top load should fix that. The primary is set at 3 turns for now although this will be one of the items to experiment with.

These are a couple of pictures with the tiny "toy" version for scale.

I dont plan to build another but who knows,  I know I could get more output with a higher LV source but that kind of defeats the object of these experiments.

So for now I have a new toy to play with and I am happy with the endless tinkering opportunities that will give me.

Thanks for looking.

Alan

P.S. I have just noticed that the power indicator LED in the circuit above is the wrong way around  should have Cathode grounded.

[jetstream]

On 11/07/2018 at 08:51, Alien 13 said:

So for now I have a new toy to play with

Great stuff Alan, is there any way to get the spark dancing through the air visibly? I'm thinking of my grand daughters next year science project...

[Alien 13]

I can get a spark about an inch long but it requires a hand held screwdriver to initiate it, I am still experimenting with the big one but will try some point sources attached to the top load when I have cracked the tuning.

The little toy does produce a tiny spark on it own, part of the sales pitch is that it can be modulated to produce sound.

Alan

[Stub Mandrel]

On 11/07/2018 at 14:51, Alien 13 said:

I have finally completed the initial build of the larger Tesla coil, I am still using the single transistor circuit but with a much better heatsink, my poor woodwork skills and inability to drill round holes in the right place has meant this project has taken a lot of effort.

I was surprised that it fired up up first time, it is a lot less finicky than its smaller brother but does not output as much power yet although fine tuning and a new top load should fix that. The primary is set at 3 turns for now although this will be one of the items to experiment with.

These are a couple of pictures with the tiny "toy" version for scale.

I dont plan to build another but who knows,  I know I could get more output with a higher LV source but that kind of defeats the object of these experiments.

So for now I have a new toy to play with and I am happy with the endless tinkering opportunities that will give me.

Thanks for looking.

Alan

P.S. I have just noticed that the power indicator LED in the circuit above is the wrong way around  should have Cathode grounded.

You're on the slippery slope now, each one will be a bigger by the same percentage and in four more versions you'll be reanimating the dead...

[Alien 13]

19 hours ago, Stub Mandrel said:

You're on the slippery slope now, each one will be a bigger by the same percentage and in four more versions you'll be reanimating the dead...

Thats the plan 

Alan

[Alien 13]

I have been playing with the loading to add some capacitance to the system and have got the output at about 30% above the medium sized coil, I think that I am getting to the limits with how much current the transistor can switch on a 12V supply but am happy with the results. 

The stainless steel garden ornament ball is OK and gives reasonable results but is quite a way off what the other top load can do but it does look better 

This is the special made from two bear cans and works very well.

I can light a neon from a meter away and get reliable inch long sparks, I may have a play with building a receiver to get power over longer distances.

Thanks for looking.

Alan

[moonomaly]

Loving the wireless power transmission, something MIT bragged about a few years ago, like coil-builders didn't exist and hadn't done it already!

The 'toy' one is nice and decently-priced, your big one looks a little too close to your telly and hifi for my comfort ;+}

Lovely work pal, nicoe coil, how did you wind it ?

[Alien 13]

6 minutes ago, moonomaly said:

Loving the wireless power transmission, something MIT bragged about a few years ago, like coil-builders didn't exist and hadn't done it already!

The 'toy' one is nice and decently-priced, your big one looks a little too close to your telly and hifi for my comfort ;+}

Lovely work pal, nicoe coil, how did you wind it ?

Dont worry the coil is only ever fired up in the kitchen away from any sensitive electronics, the coil was wound manually by turning the former on my lap, a very long process. 

I have yet to find the transmission distance with an earthed stand with a neon and ball fitted but guess it could be several meters. The Toy uses exactly the same active components so you could add any coil you like.

Alan

[moonomaly]

Yes i think you could beat 1M.

I know how long it takes,i started manually, then i built a jig operated by electric drill, then years later i bought this freom ebay :

http://lechacal.com/wiki/index.php/Albawinder