Modifying a simple shock box diagram.

[Johanx2]

Does anybody know why I did not find "Rheostats" with high resistance values ? All I have seen were very low in ohms (5 to 25 ohms). They are very high in watts, but low in resistance. There's no way I can find a rheostat of 150k high in watts ? I just wondered, anyway I just have ordered the two potentiometers that I described above.

 

[Audioguru]

A potentiometer divides a voltage and uses a low current so it has a high resistance.
A Rheostat limits a current which is high so it has a low resistance.

Nobody uses a potentiometer or rheostat at the output of a high voltage circuit like yours.

 

[Venkadesh_M]

The multicolour transition LEDs are in the market for years..

It is very interesting that 120V making arcs, because the reason for arching is high voltage and low distance between electrodes. Actually your circuit will have very very high frequency. but will that cause a kind of arc or will that make the effect of shock less on 1000s of volt. lot of questions..

Are you using toroidal core transformer? do you know the turns ratio? it is easy that reducing the voltage by tappings instead of pot. can you make it on your own?

 

[Johanx2]

Are you using toroidal core transformer? do you know the turns ratio? it is easy that reducing the voltage by tappings instead of pot. can you make it on your own?

It's not toroidal, it's just a normal transformer. 12v/450ma that I bought at radioshack. Please can you explain what do you mean with "tappings" ?

 

[Venkadesh_M]

12/450ma from 230 or 115V? 50 or 60 Hz? can you post a link or datasheet of the part you purchased?

Tappings is the technique of changing the output voltage of transformer by taking various points of output from a single coil. for example it can give you like 80, 90, 100, 110, 120V or set of other voltages like switching the winding terminals.

This is kind of example for transformer tapping

 

[Johanx2]

Oh I see, my transformer is only for 120 VAC, it does not have more terminals for 220v.

 

[Audioguru]

Radio Shack has a 120V to 12V center-tapped /450mA power transformer. Like most electronic parts at Radio Shack its datasheet only lists its color, size and weight.

If this project is powered from +6V then the output from the transformer will be a little less than 120V peak.
The output current will be high enough to kill a person who is sweating and is high enough to destroy the pot if the output is shorted or if it is zapping a sweating person.

 

[Johanx2]

Radio Shack has a 120V to 12V center-tapped /450mA power transformer. Like most electronic parts at Radio Shack its datasheet only lists its color, size and weight.

If this project is powered from +6V then the output from the transformer will be a little less than 120V peak.
The output current will be high enough to kill a person who is sweating and is high enough to destroy the pot if the output is shorted or if it is zapping a sweating person.

Well I hope not to kill anybody. I am from a town where people at the fairs pay a man who is carrying a machine with this circuit in order to be safely electrocuted. You pay the man and then he gives you the electrodes, then you know what's next . I can earn too much money doing the same thing in the streets, but you know, the risk of dying... for that reason I have been always using this circuit for private use only with my loved ones (family and friends).

 

[Venkadesh_M]

Hi
Johanx2, which country you are from ?

120V on 100k is only 0.144W so it could never harm a 100k pot of 0.5w in terms of power because assuming the avg human resistance of 500k to 1M as a load.

But there is something about the frequency that hurting everything, also that will reduce the power rating of transformer.

The transformer power rating is max 5W at 50/60 HZ but in high frequency it will also reduce because of reduction in primary (secondary) current.

I have one doubt, if you want 120V, why don you go and directly touch the incoming main supply. If you want some hands closing shock mechanism then you can just use a 120 to 120V transformer with 100k pot. I don think that will hurt the 100k.
Why don you connect you 100k directly in main supply to test it is working fine or not.

Remember I am assuming your main Voltage is 120V. if it is not then you can just use 230 / 120V transformer. I will search for a tapped transformer parallely.

 

[Johanx2]

Venkadesh_M, thanks. I just maybe understood what you said, but I think there's a reason I can't do what you said, I want the device portable, so batteries are necessary. I am from Mexico, there the shocking boxes are very common.

 

[Venkadesh_M]

https://www.mouser.com/ds/2/177/5c0069-77754.pdf

like the transformer below, but you cant use this one because it is 100VA minimum. Try in internet. also keep moving that 2W pot, because we cant be so sure about the availability of this kind of transformer.

 

[Audioguru]

I should have guessed.
The lousy and dangerous circuit is an Instructable! https://www.instructables.com/id/shock-machine/ Many Instructables are designed by kids who are only 10 years old and know NOTHING about danger and know NOTHING about electronics.
The designer says, "If you take it to school you can win a lot of $$$ money $$$!!!" Maybe some kids will pay you to kill other kids.

 

[Johanx2]

Yeah! Now that I am using the new potentiometer, all the problems are gone! There's no fire and smoke anymore! I also did take apart the potentiometer and did see how the internal design is very different from small regular ones, I am lucky if that is a decisive factor that is making everything going so perfect! I am so happy that I took some pictures in order to share my project with everybody. Some persons where I work are getting so fun with this thing, and believe it or not I have a duel with a 50 years old man for next monday, he did tried this thing and resisted until number 6 of the knob. I also have to say that the batteries were a little old, now I have put four energizer max in order to make this thing going at its maximum levels. Last time I had no opportunity to try because lunch time was ended, although I have to say that I am one of those guys who resist a lot of electricity passing through whole body, it's like, I think it's enjoyable, you definitely must try this thing, which I almost forget how funny it was.

 

[Venkadesh_M]

Amazing out look..

Good to see but hot to touch..

I don know why I will feel shock(kind of earth) from even 60, 70V.

I think i am well hydrated.

 

[Johanx2]

Amazing out look..

Good to see but hot to touch..

I don know why I will feel shock(kind of earth) from even 60, 70V.

I think i am well hydrated.

I have to say that this thing does not hurt, at least at the first levels, it does feel like when your leg or arm is very numb, many people were scared to try because they imagine that it will be a extreme shock.

I think that it will be so nice putting a led vumeter. Does anybody think that it's easy to do that ? considering that there's AC from 1 to 110v more or less. I also have to said that I burned one of those yellow cheap multimeters when I tried to measure the voltage I was getting. it was new and it was setted correctly (200v AC. I did get a weird message at the display and everything was going wrong, I did not get a clear number in the display, after that my multimeter was not able to give me correct values anymore for either AC or DC. So what happened here ? maybe the frequency was the reason of that ? I got a new multimeter, same model (I returned it at walmart and get a new one), but now I am afraid to try again and get the same result.

 

[Audioguru]

I think the zapper circuit makes very high voltage spikes on its squarewave output. The voltage is too high for your voltmeter.

I posted my Sound Level Indicator project (VU Meter) at Electronics-lab almost 9 years ago. So it has been operating for 8.8 years x 365 days per year= 3212 days.
It has a sensitive microphone and a rechargeable battery. The battery is rarely used since the charger powers the circuit.

 

[Johanx2]

@Audioguru, I was asking for a vumeter suitable to be connected to the output of the shock box (0-120v AC), so each led can be an intensity level . Do you think my multimeter will be ok setted in the range of the 500v AC ? which is its maximum capacity. the last one got burned when it was setted on 200v AC. If so just maybe I will make a special port to the box so there I will be able to connect the multimeter in order to get "numbers" of the voltage that the user is getting, I think that it is pretty good knowing that fact instead of just guiding by the 9 numbers of the potentiometer knob.

 

[Audioguru]

Sorry, you said VU meter that is used to show audio signal levels.
You want a high voltage meter but you do not know the voltage.
Since a multimeter got zapped and you had sparks then a voltage meter will also probably get zapped.

Many years ago a high voltage tester was used to measure the 25 thousand volts in a CRT TV. But the current from your zapper is MUCH less so that meter will not work.
An LM3914 bar graph IC measures voltages up to about 10V. Many high voltage, high resistance resistors can divide your voltage then drive a high input impedance opamp to drive it.
But the output voltage of your zapper is not regulated and it drops when somebody touches it so a meter is useless.

Your 12V Radio Shack transformer is designed to step down 120V at 60Hz not to step up 12V at tens of thousands of Hz. So we do not know its output voltage. It probably has high voltage spikes on top of the 120V output.

One person can feel about 50V. 120V will feel funny but can easily kill a person. Then for you to have 20 people holding hands (in series) to feel funny you need 2400V. It will definitely kill a few people or less.

 

[D.A.(Tony)Stewart]

Accupuncture Doctors use various pulses trains below the pain threshold to excite the needle and muscles. I have experimented with this for back pain by adjusting the levels from slow rep rates to swept frequency, while under supervision. The trick is if excitation is theraputic, Mo is betta.

The implementation is a trivial reed relay and pulse duration to control the current from a transistor driver into a tiny stepup coil to low voltage battery. The larger pulse genrators are used for example are automobile ignition coils, one per plug.

You can estimate the energy level from Pulse width with fixed L, V.

 

[Johanx2]

Hey guys, few days ago (thanks giving day) we had an accident with this thing. Me and some family like cousins, uncles and aunt were playing with this shocking box. As i showed you, it has 9 levels. Our maximum record was about number 7, what a very strong level, i can't even imagine overcome this level. Once we got tired of using it. My nephew which is 8 years old, kept playing with it on the dinner table. A cousin told him not to use it because you know, its a dangerous thing. All we were in the dinner room, i was serving my plate, when suddenly i hear my nephew screaming and crying as hell, it seems like he had the machine setted at its maximum level ( he thought it was on level 0) he took the electrodes and did turn the switch on, getting electrocuted. After i noticed the incident, as fast as i could, i immediately did turn the swich off, it was impossible for my nephew stop holding the tubes because his arm muscles were very tight due to electrocutation. My little nephew was very scared. He could not stop crying. Next day he was ok, very proud because he was the only one who did/tried level 9. He did not get hurt at all, his arms were absolutely fine. I can not imagine me trying level 9, it may be horrible experience. After all everybody got a lessons, my nephew will be more carefoul next time and I just concluded how this machine can not kill you.