Ferrite Core Bunnings

[Gwenda Arguin]

Solike mentioned in the video you can use a transformer to create very high voltage. Creating very high voltage without a transformer can be very hard, because you would need very high voltage rated components on the output (>10000V), while with a transformer you can pick lower voltage rating components on the low voltage side and let the transformer take care of creating the high voltage. But how does a transformer work?

When I disconnect the supply, I see spark on the primary too because the 10A current tries to keep going and creates a high voltage arc, but also the secondary voltage rises and makes an arc, especially when I add the capacitor. So like I showed in figure below, the self inductance of primary and the added capacitor are charged together when switch closes, and then start oscillating when switch opens, creating a high voltage oscillating waveform.

Also this oscillation creates even higher voltage on the secondary that as we saw creates very high voltage sparks. From the gap the sparks were arcing over, I would say their voltage was over 20,000V.

And so I created the circuit below to create a continuously arcing circuit. The way I designed this circuit, when you press SW1, you actually connect 12V across the relay coil through the relay normally closed contact. This will cause the relay to switch away, which removes the voltage across its coil and turns it off, and so relay returns to normally closed position, and hence relay will oscillate. The capacitor and resistor across the relay coil are to slow down the relay switching frequency. This is to allow the 12V to be across the transformer primary for a longer time so that it charges high enough. And when the relay switches away, we have a spark on the output. There will be sparks like a taser as long as we hold the switch.

your secondary now is the 220V side, it is not build for 10000V so it sparka over, internally between the windings, destroying the coating of the windings.

you need a special transformer that can handle the high voltages.

Hello sir, can you please give me the connection wiring diagram of this circuit. Sir i need this diagram urgently. Please help me. You can send me the wiring diagram at my mail id: (surajav...@gmail.com). Love from india

I wanted to know if this is usefull for the following project.

I want to create a pulse generator, but i need high voltage (2-3kV)and low current. I am thinking, instead of using that button, to use LM555 timer, for pulse control, and use like a motorcycle coil, not a car coil, for less voltage. Would i be able to do it?

Hi Mehdi! Is it possible for me to just use the primary side circuit/not use transformer and increase the resistance of R1 so there will be high voltage sparks? I do have small transformers but they have low turn ratio and not good enough isolation..

Hi Mehdi! Is it possible for me to just use the primary side circuit/not use transformer and increase the resistance of R1 so there will be high voltage sparks? I do have small transformers but they have low turn ratio and not good enough isolation.

I found what I believe to be a homemade taser. My dad built 30+ years ago i im trying to figure out how the thing works so i can resodder the many broken connections and get it working. Howerer im more confused now than before. Because it runs off or 6 1.5 v dc and so guess that doesnt go directly to what I assume to be a transformed out of god knows what. But I am makimg progress i know the led indicator light works. Thats a win in my book

If it runs off DC then he must have used some sort of switching circuit. You could do it with a 555 timer turning on an SCR that was connected to the coil primary. Using two such circuits I believe would produce an AC type signal. I would think it would also be easy to tune by a simple resistor adjustment.

Differrent models of coils behave quite identically across the range that is available out there. Generally, they tend to have a DC resistance of approximately 1 ohm across the primary winding and a resistance across the secondary in the order of several kilo ohms. The ratio of turns vary, but typically falls within the range of 1 to 50 and 1 to 200.

The coils would be constructed around ferrite cores and submerged in oil to handle the high voltage.

The major discrepency that you may have to deal with lies in the coil of the relay. Different relay solenoids may have different characteristics(e.g. resistance, shutoff voltage and current) which may demand a bit of trial and error with C1 and R1 to find the sweet spot where the capacitor C1 provides the solenoid with JUST ENOUGH residual post-cutoff current to sustain the magnetic field whilst the switch arm swings away from the normally closed contact, enabling it to reach the normally open contact to energize the primary of the transformer; and not TOO MUCH so that the frequency of the oscillation is significantly reduced to a point where the full potential of the transformer is not utilized. (sorry for the long sentence)

Initially when I set out building the circuit I fathomed that I could work out all parameters by theoretic calculation based on the inductance, resistance and shutoff voltage(the lower limit of solenoid voltage at which the coild is no longer able to produce a strong enough magnetic field to hold the arm in place). Later on, I decided that trial-and-error is the more efficient and less labor-intensive approach. ^lol

In a nutshell, your focus should not be the transformer but rather the relay oscillator.

Hope that could have helped you.

The relay contact power is connected to the positive side of the battery / power supply and the switch circuitry is connected to the N/c contact while the N/o contact is connected to the boost circuit.

This is very nice! Soon I will have seven coil coming out from my old truck and new truck. It is possible to drive coil with 555 timer control switch via MOSFET. Surely, there are already 555 timer flyback but I have a very little twerk on my own. It is going to be better than my old 555 timer I used from website as soon as I making bigger twerk.

The way it makes the pulse period longer is by storing the charge and releasing it into the coil when is turned off. The resistor drops the voltage making the electricity flow more lightly. And the circuit question can be explained like this: Michael faraday thought that since you can make a magnetic field by making electricity flow throw a copper wire you can generate electrical energy via a magnetic field wirelessly. So the magnetic field of the primary can generate electricity in the secondary.

you can think the resistor and capasitor with the relay coil as an oscillator.so oscillating frequency is determined by capasitance and the inductance of relay coil.hope this may help you to understand.

FBTs operate at higher frequencies and may not be as efficient with relay oscillators as is an ignition coil. Obviously if you could build a circuit that could adjust to the different input impedance resulting from varying output conditions, you would get the optimal results.

Hey, where did u buy your capacitors?

also cant u make a video about how to make a little taser that u can have in your pocket with transformers and all.

Where do u buy the cards to fit the capacitors on?

First, I was wondering if the relay could be replaced by an On-On switch ?

Secondly, What amperage should my diode be able to withstand?

Thirdly, Where do you connect the negative on the part of the circuit containing the inductor?

Awesome design! I have built it as shown in your circuit diagram but instead I have used another similar type 12V dc relay with half the impedance and an audio transformer with a higher turns ration i.e. 4k:8R and without the TVS. However, I could get a couple of sparks per second over a distance of a couple of millimeters not as apart as shown in your videoclip. I could get some decent sparks at distance of around 10mm only if I added a 10-stage villard circuit with 1N4007 and 10nF/1kV caps. But again instead of having multiple sparks per second I could still get only a single spark every half second. Do you have any idea what might be causing this and how to increase the frequency of sparks per second? Thanks in advance for your help

I responded on youtube but figure it would be better to go on here. I would like to use this to ignite propane with an arduino, can you offer any help as far as this? I am new to electronics but how could I go about doing this?

power supplies salvaged from a personal computer supply two voltage levels 5 volts and 12 volts. they are freely available.

depending on the individual power supply, the 12 volt output is usually well over 20 amps. many u tube videos show the details.

These power supplies are overload protected so they are great for experimenting.

Good day,

i am attempting to build one of my own, but i have some doubts about the circuit:

1. i have two 6 volts eveready super heavy duty, that are able to produce 11 A , could it work if i connect them in serie?

Hi, as the others this video is really great and funny. I planned to make my own taser but by living in EU it is quite difficult to find 1uF 250V ceramic capacitors but I was asking myself if it was possible to use a 10uF 250V MKS film capacitor to get the same result because I can find it really more easily ?

How do you calculate the peak voltage of transient response of LC parallel tank circuit when you open the switch? Given you know the values of L, C and initial voltage supply (and maybe parasitic resistance).

You add them up for total energy (Et). Now while they are oscillating, in some cycle the entire energy falls into the capacitor. Now you can calculate the peak voltage using the same energy formula: Vc[peak] = SQRT (Et / (0.5 x C))

I was wondering if I could use a tesla coil transformer instead. I saw the tesla coil video and thought that I could use that kind of transformer. I would have the same circuit you used for the taser.

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