Musical Tesla Coil Kit (instructions)

Intro: Musical Tesla Coil Kit (instructions)

A couple of years ago I've built a large tesla coil. Since then I was curious about how to make it play music.
I had made a plasma speaker once based on a instructable with a TL494 and a flyback transformer. Which worked pretty good till something broke again.

Recently I found this musical tesla coil kit on ebay. And decided I should give it a try.
Because the instructions were in Chinese, I made an instructable so people with little electronics knowledge can make this kit as well. You can find a copy of the schematic and original instructions on my website.

The arc length is only a few millimetres, but the sound quality and volume is pretty good. With an additional amplifier like a headphone output from computer speakers.

STEP 1: Order the Kit

Get your hands on such a kit, I bought mine from ebay but I found the same kit on Aliexpress and Amazon as well.

You can get the parts yourself or just buy the kit.

When I bought mine I paid $12 now it is only $5 and free shipping: Musical Tesla Coil on Ebay

STEP 2: Included in the Kit

• 2 * heatsinks
• 2 * resistors
• 2 * resistors
• 1 * Female DC power connector
• 1 * Female Audio Jack
• 1 * Mosfet
• 1 * Mosfet
• 1 * Transistor
• 2 * LEDS Blue and Red
• 1 * Capacitor
• 1 * Capacitor
• 4 * stand-offs and screws
• 1 * aux cable
• 1 * pcb
• 1 * secundary coil
• 1 * piece of wire
• 1 * bag of thermal paste
• 1 * neon lightbulb

STEP 3: Placing the Resistors

In the kit are 4 resistors:

• 2 x 2K with the colour bands RED-BLACK-BLACK-BROWN
• 2 x 10K with the colour bands BROWN-BLACK-BLACK-RED

Place them at the right place according to the silkscreen (white text on PCB) or have a look at the picture.

STEP 4: Placing the LEDS

For the LEDS it's important to check the polarity and to be sure you place them in the right orientation.

On the PCB are "+" symbols this is where the anode of the LED has to go, This is the LONG LEG of the LED.
Another trick is to check the flat side on the plastic of the LED (this is the "-" or the cathode, short leg) this has to go to the flat side of the circle on the PCB.

STEP 5: Placing the Capacitors

STEP 6: Preparing the Mosfets

Before you mount the mosfets onto the heat-sinks you'll need to apply some thermal paste between them.

STEP 7: Placing the Mosfets

STEP 8: Placing the Connectors

STEP 9: Making the Primary Coil

STEP 10: Placing the Secondary Coil

Before placing the secondary coil you'll need to do the following preparations.

From both sides of the secondary coil you need to pull off a little of the coil wire.
One of the wires should be "stripped before soldering" you can do this in many ways.

• use sandpaper to sand off the varnish
• use a lighter to burn it off
• scrape it of with a knife
• set your soldering iron to it's hottest temperature and apply solder to the wire and hope it solders through the varnish. (What I did)

STEP 11: Add the Standoffs

STEP 12: Testing Without Sound

STEP 13: Testing With Sound

Comments

[christian2gothic1]

i assembled one of these too. at the time I used instructions I found on you tube. my blue LED doesn't seem to light up, but the plasma speaker works just fine. I got interested in this project because I want to make a bigger louder one. I'm not sure what to do to make this bigger an louder. Does Anyone have any ideas on how I could go about making this bigger and louder. I'm hoping to make it as loud as a typical 'boom box' portable stereo. I realize it will draw a lot more power. I was originally thinking to get a 'breadboad' and experimenting with simply using the higher powered larger components. larger mosfets, diodes that handle higher voltage, ect. I realize the audio input and related components would likely be the same or similar. I figure the windings would need heaver gage wire, and more turns, and eventually fine tuning to get the best arc. I figure the mosfets may likely need fans or other means to keep cool, like the liquid cooling used in some high end computers. Does Anyone have any ideas where I could go to get useful info on this project? does anyone know anyone who would help me??

[thomaskarkoski]

The Tesla coil speaker my first LED light won't light up the LED number one what could be the cause of that please

[CrazyGuyN2O]

You might need to reverse the direction of the primary. Instead of being a winding that goes from bottom to top, make it go from top to bottom.

[cas-studios]

Did anyone work out what the neon was for?

[Caspar]

Hold it by the wires and wave it near the coil.

[ross.jmrauto]

The kit I made gave no instructions on number of primary turns (secondary is 350). How did you come up with one turn for your project? I was given enough wire for 7 ish turns.

[GerardL17]

The circuit diagram says one turn (1T). The picture in the Chinese instructions shows just a single loop. If you use more than one turn for the primary, it will reduce the voltage on the plasma coil (secondary).
The instructions also say "if the primary and secondary coils are ignited, loosen the primary coil to keep it more than 1 mm spacing from the secondary coil" (Google translation; I don't read Chinese).

[jgandalf]

There is a sub heading for "Testing With Music", but there is nothing there! This is the part I especially wanted to see...

[geo bruce]

I remember my aux signal wasn't loud enough so I first amplified it with an audio amplifier and used the headphone output. This did the trick for me.

[internia]

Thank you so much, I bought a very similar kit with even worst Chinesse instructions... I successfully followed yours and it worked at the first time. Great!

[dylan.mcnamee]

Just a note for folks: we got our MOSFET transistors swapped (didn't notice the markings) and the LEDs lit up, but nothing else. It was difficult to desolder and swap them, but once we did, everything worked great - yay! Superb kit, and thanks for the instructions.

[Chris Dancer]

Thanks Bruce. I was given the kit as a present with no instructions about how to assemble it or what it should do, so your instructable was very useful.
A couple of things I discovered for myself which were not clear from your instructions:
(1) The wire on the top end of the coil should be stripped (or soldered), cut short and left sticking up. This is where the spark comes from!
(2) If both LEDs are lit then it's oscillating. At first mine was working (both LEDs lit) but no spark. I have no idea where the current was going. I tried reversing the rotation of the primary wire (using a longer wire) but that just made the red LED go out. Replaced the original wire and I got a spark!
(3) Power inlet is a 2.1mm power jack, wired centre positive.
(4) Current consumption of mine is about 0.7A at 15V. Those heatsinks get hot!

[Marvin the Martian]

Answering some above unanswered questions:

1a. Electron1979 "What is the pad inside the 2 circles on the PCB
for?": I think the question is for the mounting/soldering hole under the
big (secondary) coil? That hole is absent in the newer board --- and
unused in the instructable here.

1b. Electron 1979 "What did you do
with the wire in the centre of the coil?" That's the un-soldered,
un-stripped end of the secondary: At the very first photo and also the
last "Add the Standoffs" photo, you can see a short end of it hanging in
the centre of the secondary coil.

2. DiamondD11 "you don't mention what the MOSFETS or the CAPACITORS are":
--Capacitors: That you can read from the board (e.g. last picture step3) -- the black one is 10µF [on the body it says "HDF 105*C 25V 10µF"], the fat flat one is 105(µF) [on the body it only says "105"].
--Mosfets: In my kit, one says B18 BD243C (It also says F which looks like a logo, and an E-inside-a-circle); the other says P75NF75 GKNRP V3 CHN ?05 (where ? can be a B or 8, hard to make out). It also has a logo and an e3-inside-a-circle. BUT! Notice that the board in the photo (last photo of step3, again) clearly says "BD243" for one and "80NF07" --- my board says "BD243" and "P75NF75".

3. Mondo1 "This has 2 different numbered mosfet. What happens if you reverse": I do not know enough to know if it matters, but again if you look on the board you see it clearly marked "BD243" for one of them, so put that one there?

Background: I have a newer (2018) board, there are some slightly different components (3white LEDs of which only 2get used, and 3x 10K resistors not 2x, and one differently-named Mosfet). There is NO thermal paste with my kit.

[BodokiG]

Hello all!
I try to answer the questions in row.
The circuit has a small flow. Reverse the LED on the base of the TIP41 (it should point to the base, from the GND), in that way, it will protect the base from excess negative voltage, while it won't be stressed with breakdown voltage. In short, it will lit during operation. :-)
Those, whose circuit doesn't start to oscillate: reverse the winding direction of primary coil. It can work in only one direction, as the climbing current of primary will have to induce the opposite polarity in the secondary. And make sure the primary is wound even the lowest part of the secondary.
There is only a via in the inside of the coil, on the PCB, don't solder to it.
I fastened the coil with UV glue, but it doesn't matter, just have short cables and avoid the coil's upper part to get close either the primary, or any part of the circuit-it may cause shortage between windings.
Thermal paste is a must, just like proper cooling!
FET can be anything N channel able to source few ampers at least. Capacitor is of your choice, 1 uF ones. Preferrably foils.

[Sparky2990]

I'm unsure now which way LED1 should be installed (it didn't light either way) and I was surprised that the direction of winding the primary coil *does* make a difference between nothing working and good operation!

[Liondargent]

I tried to wound primary differently no success,
which led are you talking about, led1, led 2 ?

Forget it !!!!
I found the problem, I mismatched the mosfets !!
As a professional i'm not proud of that !

[Liondargent]

Hi, some problem after doing the kit:
what should I see, any electric arc coming out at the coil top wire ?
Does the both led should lit together (it's my case)?
Under 20 volts there is no amps, and radiators are at room temperature..
I'm suspicious about polarity of led 1 does positive is at the closest edge of
the circuit board ?
Do you have any clue ...
Thanks for the reply.

[Mondo1]

This has 2 different numbered mosfet. What will happen if you put them in the wrong location.?

[gakibler]

Thanks!Just built it and it all worked great. Great spark. I plugged my phone it and it played music great! Driving it with about 19vdc. Second time I tried the music, it played for about 4 seconds then quit and won't play any more. Still have a good spark. Any suggestions what might have died?

[Liondargent]

Hi Bruce, I complete the kit, it seems not working...
what should I see, any electric arc coming out at the coil top wire ?
Does the both led should lit together (it's my case)?
Under 20 volts there is no amps, and radiators are at room temperature..
I'm suspicious about polarity of led 1 does positive is at the closest edge of
the circuit board ?
Do you have any clue ...
Thanks for the reply.