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Mini 9V tesla coil

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  • Components
Last response: in General UK & Ireland Discussions
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July 11, 2010 10:11:08 AM

hello im wondering since i have a few random electrical components hanging around my room could i make a minature 9v tesla coil and if so can someone show me an easy circuit diagram to use then i shall msake a better 12v one. :) 

More about : mini tesla coil

July 11, 2010 4:16:29 PM

isn't there any easier one than that using a capacitor and 9v battery?

i don't really understand the timer
July 16, 2010 10:10:53 AM

*sigh*

No, there is no easier one. The core of a Tesla coil is a high power transformer (most commonly used is a flyback transformer from a TV set, or CRT monitor - you will NOT find one of these in an LCD). This requires a large amount of current to operate, in addition to a high-frequency alternating current (AC) feed. The timer is there to mimic the AC feed by providing a high frequency pulse.

EDIT: As an aside, the circuit linked above describes pretty much what I did below, only using an NE555 timer instead of a flip-flop. Plus, the guy who did that page doesn't seem to know the correct context for the word 'flyback'. If you have ever opened a CRT monitor or TV, that thick cable going from the top of the tube to a black boxy thing on the circuit board is called the 'flyback'. The black boxy thing it connects to is the 'flyback transformer'.

You can run one off a PM9 9V battery, if you don't mind it going for half a second before the battery is drained. A lead-acid car battery is a better option, though the best option is a direct mains feed through a step-down transformer. This also obviates the need for a timer, since it has a 50Hz AC feed to play with.

Just 'a' capacitor is not going to cut it. Standard electrolytics work OK, but don't last under these conditions - your best bet would be to use Tantalum or ceramic disc capacitors throughout the project. Actually, you do get electrolytics that will last, of the solid-gel type, but they are prohibitively expensive for hobbyist projects.

If you want to use a battery and a cap just to generate a spark, then you will still need a couple of transistors, resistors, and so on (the components for a flip-flop, basically), plus a transformer or autotransformer (i.e. car coil) to step up the power to produce the spark.

Flip-flop circuit. Changing the values of the resistors and/or capacitors allows you to change the peri - uh, how often it produces an output pulse. You'll want to take the pulse from one of the LED + terminals.

The car coil/autotransformer. This will allow you to turn a low-voltage pulse into a high-voltage spark.

If you can increase the frequency high enough using the flip-flop, you can produce a constant spark.

I have built a similar circuit to the one I describe above - similar, due to me using an NE555 timer IC tuned to produce a 2.6KHz (2,600 pulses per second) signal through a cascaded coil setup to get a very high output voltage. The use? Very high power Bitter electromagnet (on the order of about 26 Tesla) for high-energy plasma containment. Don't ask. I mention this because when I fired up the circuit (test before connecting the magnet) it produced a spark across a 70cm gap.

Using the flip-flop + car coil method is about the easiest, but again, scale up the battery or it will not last long. If weight is a concern, look into sealed lead-acid alarm backup/UPS batteries in the 3 ~ 7Ah region. Plus, they are rechargeable using a standard 12V car charger.

This will be about the easiest method of making a 'Tesla' coil. It will not be a true Tesla coil, since a Tesla coil produces a spark at the single electrode to any grounded item within range, while the spark generator described above produces a spark between two electrodes.
July 16, 2010 10:56:39 AM

God, you guys are sad.
July 16, 2010 11:20:25 AM

Sad? I'm actually impressed!
July 16, 2010 11:36:13 AM

Come closer and I'll show you something impressive....
July 16, 2010 1:19:26 PM

They do that by adjusting the input frequencies. That, actually, is a very entertaining use for a Tesla coil. It won't be that difficult to pull off either.

Although an op-amp isn't going to cut it... I might need to get some power FETs...
!