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555 driver for ignition coil

Thread starter #1
Morning guys.. just had a question that maby someone can answer. I have built a ignition coil driver from a simple dimmer from home depot with a cap that runs off 120 volts ac. I can turn the dimmer and it changes the spark from the output of the coil. If i lower the dimmer all the way i can hold the output of the coil and transfer the light shock to another person. I am not sure if the dimmer is lowering the freq of the output or the power of the output. So I guess im asking dors anyone know if its limiting the freq of the coil or power say from 0kv and when i turn the dial is it just allowing more of the chopped ac into the cap and diacharching the cap faster... i know im rabling now so ill get on to the main question lol. If i build a adjustable 555 timer driver and adjust the pulse to its highest will this pulse the coil at such a high freq that i may touch the output with minimum shocking to myself. Im thinking of skin affect at higher freq. Also am i correct in thinking that the higher freq will also limit current on the output?? I know very long post for 2 questions lol. Any help would be great thanks everyone.
 

spec

Well-Known Member
Most Helpful Member
#2
Hi Clint,

It is strongly advised that you stop touching that ignition coil. The voltages from an ignition coil can be lethal.

The basic rule with any electronics involving a high voltages, or potentially high voltage, is that you do not touch them when they are operating, or even plugged into a power supply.

spec
 
Thread starter #3
Morning yes i understand the output voltages from the ignition coil can be deadly. I guess i should go into detail on why i would be doing such a thing.. i am building what one would call a violet ray from the 1900's. I need a high voltage low current device for this to work. I know many that have used a flyback from a tv converted to ac because it has such high freq and are able to touch the output with no issues. I have no flyback but i have the coil. Am i correct in thinking that if i change the freq of the 555 timer to a very high freq then i lower the current coming out of the coil and also cause a skin affect and have the 30-50kv run over the skin..
 

spec

Well-Known Member
Most Helpful Member
#4
Morning yes i understand the output voltages from the ignition coil can be deadly. I guess i should go into detail on why i would be doing such a thing.. i am building what one would call a violet ray from the 1900's. I need a high voltage low current device for this to work. I know many that have used a flyback from a tv converted to ac because it has such high freq and are able to touch the output with no issues. I have no flyback but i have the coil. Am i correct in thinking that if i change the freq of the 555 timer to a very high freq then i lower the current coming out of the coil and also cause a skin affect and have the 30-50kv run over the skin..
Either way Clint, what you are contemplating is dangerous.

But to answer your question an ignition coil from a vehicle is completely different to a high frequency transformer as found in CRT TVs.

spec
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
#5
Having hooked up a 555 to an auto ignition coil in high school in the 70's, sparks were blue and almost like jagged lightning strikes about 10" long. Burnt holes through paper. Since I used another project as a driver (A solid state vibrator for a car radio) the frequency was about 200 Hz. It was also, I think a 6V coil operating at 12 V. It would occasionally arc over from the output to the nearby screw.

Automotive systems do have a ballast resistor that limits the current somewhat. I really would not want to be a guinea pig.

For a science experiment I did make a 3 kVDC supply, but it broke, so I ended up taking the anode off a TV and using that to finish the biology experiment.
Later, professionally, I worked on electron beam power regulated supplies (15 kV @ 1.5 Amps) and X-Ray power supplies ( 100 kV @ 0.1 Amp) and even 13.56 MHz RF transmitters with a power output of 1 KW (The voltages inside that transmitter were up to 3000 VDC. Don't forget the occasion work on a TV.
 

Dr_Doggy

Well-Known Member
#6
also: " touch the output with no issues"
even flyback sparks can do long term damage to the nervous system which could lead to loss of use or feeling to digits(fingers, hands ,...ect) ... even if you dont feel it shocking you...
 

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