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inductor...HELP

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cobra7_nz

New Member
HI,
i was trying to make a circuit that would get bout 100V with a 1.2V battery. i figured having a battery connected 2 a resistor then a inductor and a switch would work with a capicator in parallel so when the swich ws turned off there would be a surge of energy.

ANYWAY, i went 2 my local electronics store but couldnt find any inductors. do they go by a different name or are they not readily available?

HELP

pj
 

mattg2k4

New Member
They aren't as common as things like resistors and caps, radioshack has about one of two inductors I think. If you check around you may be able to find some, but if not you can order them online.

I have made a circuit similar like the one you are describing. All I did was hook a 555 wired for a high duty cycle at what I think was 17kHz, you can try different frequencies for best results. I tried out a bunch of indcutors that I've got lying around, most of them are salvaged from things I take apart. I found that one of the coils from a power transformer works just fine in a pinch.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
cobra7_nz said:
HI,
i was trying to make a circuit that would get bout 100V with a 1.2V battery. i figured having a battery connected 2 a resistor then a inductor and a switch would work with a capicator in parallel so when the swich ws turned off there would be a surge of energy.

ANYWAY, i went 2 my local electronics store but couldnt find any inductors. do they go by a different name or are they not readily available?

HELP

pj
Inductors are fairly uncommon components, for an application like yours you would normally buy a core and wind it yourself.

I don't know how well it would work, what kind of current are you hoping to get out of it?.
 

cobra7_nz

New Member
well im trying to recreate a "shock pen" one of my friends has. A pen,using a AAA battery, zaps you wen you click it. The local electronic stores has things called RF chokes and some or other coils? are these similar? im basically trying to get high volts, low amps from a AAA battery...maybe u guys no a better way?
 

Agent 009

New Member
Well, it could if you have enough current: Try it with a single AAA battery and connect (for a very SHORT time) the two terminals with a wire, then break the connection repeatedly, you should see a flash... Believe it or not, because of the surge of enery, I nearly got electrocuted :evil: -well not electrocuted, but my finger melted a little :shock: -, with 2 AAA in parallel... But surely you won't get as high as 100V. Think of it in an 'engineering' :wink: way: V = R * I. For the same V, if R is very small, I will be very large. That's your input circuit (the circuit that must give out the 100V). Now, for your receiving circuit (the circuit that must get the 100V), manipulate the equation, actually it's Ohm's law, to get R = V / I. Now for the same R, if I is very large, so must V be... I think I made it a little bit clear :? :D :shock:
 

cobra7_nz

New Member
not to be an annoyance but what does that mean in stupid talk? im new to electronics just really started. Also 100V was just a guess i just want enoguh that would give my friends a shock...how would you do it?that is get a big voltage surge from a small AAA battery source?

Grateful for any help
PJ :)
 

Agent 009

New Member
No annoyance at all! Anyway, I'm not so new in electronics, either (I'm still a student, 2nd year), but OK, in stupid talk: you want to
give my friends a shock
:evil: !! That's nasty ****! But you asked, and I'll try to answer: To get a shock, a current must pass through you, which comes from the AAA. Just having the battery won't be a blast, so I think, I think you should have a capacitor (now that's some serious :twisted: shitty :twisted: component for blasts: you connect the capacitor (or 'Condensateur' in french), in parallel with the AAA, and wait (maybe few seconds, depending on the capacitance of the capacitor) to charge completly. If you'd like to have an idea, think of the time of full charge to be 5 * t, where t = R * C (you probably should have learnt that!). Now R is too small, because there's no resistance in the circuit -by the way, there should be, to protect the battery. Have your friend's arm touch the terminals of the capacitor (connect'em to long wires that you put on the victim's limbs) and the capacitor will discharge on them. Now AT YOUR OWN RISK, you must choose what the capacitor would be. Have it as high as 1F, you'd kill your friend :shock: . Now, we don't want that, do we :? ?
 

cobra7_nz

New Member
so all i need is a capicator and resistor maybe? ive got a 63v 47uF capacitor here...is that enough? i played with it but didnt really get anywhere. i read that for a good shock :)P) i need high volts and low amps. will just a capacitor do that :? ? i appreciate all the help even tho im just playing round. this is WAY better than anything ive found using google.
 

Agent 009

New Member
Hehe, 10x. Wait till I find a way of showing pictures in my posts. I drew a quick picture of the circuit i'm talking abt.[/img]
 

stevez

Active Member
When current flows thru a conductor (wire) a magnetic field results.

If you take a coil of wire by itself - there generally is no magnetic field present. If you connect a cell to each end so that current flows a magnetic field begins to build. It builds quickly but the time it takes to build is finite and measurable. At some point the current is flowing and the field has grown as big as it will ever be. If you disconnect the cell the magnetic field begins to collapse. As with the building of the field, it does take a short time for the field to collapse. As the field collapses it induces the flow of electrons - essentially creating a voltage between the ends of the coil. That's how the "spark" is created.

A transformer can be two coils wound in close proximity to each other. When an AC voltage is applied to one coil the magentic field builds and collapses as a result of the AC current flow. The building and collapsing of the fields induces a flow of current in the other coil. If each coil has the same number of turns then the voltage in one coil is the same as the other. If the number of turns is different then the resulting induced voltage is proportional to the turns ratio.
 

Roff

Well-Known Member
Agent 009 said:
No annoyance at all! Anyway, I'm not so new in electronics, either (I'm still a student, 2nd year), but OK, in stupid talk: you want to
give my friends a shock
:evil: !! That's nasty [bleep]! But you asked, and I'll try to answer: To get a shock, a current must pass through you, which comes from the AAA. Just having the battery won't be a blast, so I think, I think you should have a capacitor (now that's some serious :twisted: shitty :twisted: component for blasts: you connect the capacitor (or 'Condensateur' in french), in parallel with the AAA, and wait (maybe few seconds, depending on the capacitance of the capacitor) to charge completly. If you'd like to have an idea, think of the time of full charge to be 5 * t, where t = R * C (you probably should have learnt that!). Now R is too small, because there's no resistance in the circuit -by the way, there should be, to protect the battery. Have your friend's arm touch the terminals of the capacitor (connect'em to long wires that you put on the victim's limbs) and the capacitor will discharge on them. Now AT YOUR OWN RISK, you must choose what the capacitor would be. Have it as high as 1F, you'd kill your friend :shock: . Now, we don't want that, do we :? ?
Don't get your hopes up. The capacitor will only charge to 1.5 volts, no matter how large the capacitor is. You have to have an inductor or a transformer to get 100v from 1.5v (well, ok, there are some other ways, but they are even more complex).

Agent 009, you aren't doing any favors by posting answers that will only cause others to waste their time and possibly their electronic components. One of the key attributes of a good "electronics master" such as yourself is that he knows his limitations. If I am not absolutely certain that I have a helpful answer, I keep my "mouth" shut.
 

jem

Member
I concur with Ron H!

About the RF choke business, an RF choke is just an inductor (usually small value - depending on the RF frequencies involved) which more or less blocks RF but passes DC easily.

As for your idea, you probably need some kind of oscillator with a fairly high primary to secondary ratio. Not sure 100V will give you the kind of jolt you are describing. You can try to increase the voltage by using a voltage multiplier in the secondary circuit.
 
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