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relay coil inductance?

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danielsmusic

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i look on this site and while searching i found that you can create a crude "ac" from a relay.
so i wired the relay up so that when it switches on it switches back off again.

when i measure the voltage on the coil it is flutuating from 0 to 100v
is this just my multimeter or is this stepping 9v to 100?

it gives me a electrical shock across my whole body! and it make my musles twich badly, not to mention that is hurts!!!
 
Are you feeding the relay with 12V DC? I believe you are experiencing "comutation", very short and strong voltage spikes (transcient pulses?) that are created when the coil is disconected.

(Don't flame me if I am wrong, this is not my area of specialisation).
 
im using 9V dc, i had the same idea as you, the relay coild is creating voltage spikes just like a inductor.
 
Joel Rainville said:
danielsmusic said:
it gives me a electrical shock across my whole body! and it make my musles twich badly, not to mention that is hurts!!!

Don't try this on a small animal then :lol:

Unless it's a rat :p:lol:
Actually when I was a greene at High-school, We had this Matricalation party, where we had to sign a paper that we would serve older students. While I was signing the paper, I got (and everybody before and after me) electricuted. The pen and a coper plate that I was touching was connected to the RELAY HV generator. I tell you, that was not very pleasent feeling.
 
Don't try this on a small animal then :lol:

Unless it's a rat :p:lol:

yea i heard somewhere the animals bodys are not as tolerent as ares, i think even a the pizzo thingy out of a lighter can kill a animal am i right?[/quote]
 
im going to step it up with 3 transformers and see if i can make a tesla coil.
 
danielsmusic said:
im going to step it up with 3 transformers and see if i can make a tesla coil.
Haa, I doubt it :lol:

Post a circuit diagram of what you're doing. I think someone electro has something like that in the projects section.
 
Yea the reley coil is steping up the voltage.Reley coils are often prety big.

So wen i thurns on an magnetic field will build up around the releys coil(This filed also puls the contacts togeter so the reley swicthes).But wen we sudenly disonect the coil from its power source that magnetic field will break down and get converted back in to elecriceti.(Becose you cant destroy energy)This makes an high voltage pulse the oposite polarety as the power suply it had.

This is also why there are didoes over releys.Since the high voltage spark cod reduce the lifetime or destroy the controling electronics.

Some switch mode powersuplys work this way.

This field can also break down in an nother close by coil. Thats now my shocker makes up to 3000V whih an 220V transformer.It cod make more but the mains transformer is not made for that high voltage and starts sparking betwen the windigs.(You can hear it as cracking)
 
Oh and wireing transformers after a nother dosent work.Bust you can perelel primary windings and serial secundary to make an higher output.But the transformers have to be identical.
 
Yea i did that one wen i was bored.

Note that this also makes redio interference becose of the sparking betwen the contacts.It interefrs mostly whith TVs

Even an pice of wire has some inductance becose filed builds up around it.But this is very very vrey litle.
 
zachtheterrible said:
danielsmusic said:
im going to step it up with 3 transformers and see if i can make a tesla coil.
Haa, I doubt it :lol:

Post a circuit diagram of what you're doing. I think someone electro has something like that in the projects section.

Actually I think that we had a crude tesla coil with a crude relay switcher for HV in high school. It didnt work for some reason, I was elected to fix it. Never got around to doing it...
 
drrogla said:
Actually I think that we had a crude tesla coil with a crude relay switcher for HV in high school. It didnt work for some reason, I was elected to fix it. Never got around to doing it...

It's been around since Victorian times, they used to have 'shocking coils' which were basically a relay and a transformer. You all hold hands, with the end two holding the wires, and turn it ON - it demonstrates that you all get the shock 8)
 
this is the schematic:
 

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