I am trying to finish an effect, using some props but in a different way we usually used them. I will post all when I finish it.

but.. I know NOTHIng about batteries and electricity and I need help.may be some of you can help me.

I need to heat a piece of.. metal.. because this metal has to heat "another thing".
is has to be with batteries, no elcetricity.

in order to make me understand, something like the bags that heats when you open o cracks, to put in gloves ... the same shape.. but I have to have the control to turn on and off the heat.

you know if exhist something like this? any ideas? some class of metal that heat if you connect any buttery?

the power of the heat must be something like you use when you writte something wiht lemon and want to appear..

sorru for my english.. I hope you all can undestand what I mean..
thanks

karvis

If you are trying to heat something written on paper with lemon juice, you need hot air, not just electric heat. It would help to know if that's what you're trying to accomplish, otherwise we'll have you setting the paper on fire with all sorts of battery operated gizmos.

Thanks spellbinder, but it is not for the lemon juice, it was an example, although, I have tried to put a paper with lemon juice over a hot bulb and it works.

I just need to heat a metal o something very fine in a frame,

Like a portable flashpot?

Not exactly bryan. only need to heat a piece of peaper, no nedd to inflamable something.

I asked if anyone know something, cause when I got one of my ilusions shows, I played with batteries, flash pots and so, and sometimes, I connected some buterries to some thing, and without knew, all the mecanism heated due to the voltage o something, .
that effect I wanted to do know, heat a piece of metal ( I think) and this will heat the thing I want.
aggg, difficult to explain jeje

Why don't you tell us exactly what you're trying to accomplish - the effect? That will make it wasier to give you some advice and direction...

The movement of the energy through any metal touching both contacts of a battery will get hot. The size type and thickness of the metal, and the strength of the battery, all help to determine how hot.
You can take a 9vt battery and have it loose in your pocket, it will heat a coin pretty well.
You can take steel wool, very fine wires, and touch that to the same battery and get a small ball of very hot, ready to start a fire, metal.

As you see, the results are determined by several factors, and knowing what you need to do, will really make it easier for folks to help you out.

There are some battery igniters that are re-useable, and some that are one time use. both get hot, maybe too hot for what you need, maybe not.
Kay

I've had luck with a 9 volt battery. It's portable and you can get the snap on terminals with wires from radio shack.
Ray

Ok, you are all right. this is the effect. I hav the trick sympatheinkk, from mathieu bich. I don't want to use any flash paper nor people know I use flames o heat.

I am looking for something o make something to hide in a book, or in a pad. so putting the paper with the ink over "this" make disappear.

I would like it to be some electrical to control the momento I want the ink disappear..

you think it is possible? I thin so, but my knowledge about some things is poor...

open the qustion here.. I am sure we will have any chance...

thanks egai folks

Karvis

NO IDEAS?
ANY ELECTRICIAN OVER THERE?

I am currently experimenting with nickel chrome (nichrome) wire. It's the sort of wire used in toasters and electric heaters. It may be suitable for what you want. You can get it from electronic/electrical suppliers.

Can you give us an idea of the temperature range you need? That along with the amount of time you need to apply energy will help with determining the electrical requirements.

I saw a flat heater on a web site made of a spiral etched printed circuit board, if it does not need to be too hot it could fit easily into a book cover or clipboard.

You can make a heating coil out of most any kind of wire. Nicrome is probably best, and is easy to come by. Many hobby shops carry it , generally for floral wire. You can wrap it around a circular object like a pencil or nail,then remove the pencil or nail. Your heat will depend on guage of wire, number of turns, spacing between turns, normal resistance quality of the wire material, and the size of the battery (Amps are more important than voltage, since ur creating a resistor and resistors slow down current (flow) thus the amperage of the battery source, though voltage will be a factor, at least according to ohm's law. Note that you will not get an "instant" cooling following disconneting the power source, it will stay hot for a while.

Sunce you really don't know much about electricity and doing things incorrectly could actually make the battery explode depending on the battery type, why not use something where that is already figured out?

For lower temperatures, you could take the heating element out of electric socks. These are used to heat up your feet in the winter and can be found at Sporting Goods shops in the USA.

If you want higher heat, but in a localized area, you could use a battery powered soldering iron. They can be fit into something the size of a book.

Another option is a cauterizer used in medicine to cauterize woulds and close blood vessels. These are battery operated.

Yet another option is a battery operated foam cutter. This is used to shape rigid plastic foam and can be found in many crafts stores.

Hi Marty,

Often in Camping supplies and Recreational Vehicles supply catalogues there are 12 volt coffee cup heaters to brew hot water in a cup. This could be soldiered to the bottom of a plate of copper or use any JB Weld products to "glue" it to any metal plate.You can cut the cigerette lighter plug off and connect it to a different battery source even two 9volt batteries.

Good luck,
Dr. Solar

Dr. solar is close here I think guys but also Include a normally open swith of some type to break the circuit when not in use maybe a push button embedded in the spine of the book?

I think you need to know how hot it must get and how long it must maintain that heat before you can proceed much further. Get a thermometer and an electric skillet and find out the minimum temperature you need to trigger the effect.

I agree with mkiger. If you can pin down what temperature you need, it will be easier for folks to help you.

Depending on your temperature needs, perhaps another option would be to use Peltier Junctions, like these:

http://www.allelectronics.com/cgi-bin/ca......ons.html

Ross Hironaka

The only trouble is that Peltiers use a lot of current, offhand I do not know how much per degree or even if it is variable like a resistance heater, but you might be able to fit enough batteries into a hollow book (assuming the effect only takes a few seconds). I like the idea, it is a very elegant solution that bears looking into.

Note, do NOT use the coffee water coil heaters without them being immersed in water, they will burn up very quickly.

Karvis, I might suggest you go to the local high school, (secondary school) and ask to speak to the teacher/instuctor who works in tools. If there is no "shop" class in spain, then ask to talk to the man who keeps the buildings running, the one who does the maintenance, he will likely know something about basic circuits, or be able to tell you someone who does that can answer your questions or help you build what you seek.
There really is more to this than solderinf wires and hook up a battery! If it were a small enough area, I would say take a flashlight apart and use the bulb as a heat source under your paper, you can paint it black to hide the light, but the surface area of heat will be rather small. It will be battery powered, and have an on off switch, etc.
For a larger surface area heating effect, consider some of the small portable travel irons for clothes. I have seen cordless re-chargable irons in the store, they might mean you need a bigger book, but they will recharge, and can be switched on and off, with a temperature adjust. (why re-invent the wheel)

kay