Help with a circuit?

[RobotLizard]

Hi everyone,
I'm trying to build a simple circuit, but need some help to make sure I'm doing it right.

Basically I need to make a wire heat up when I turn the circuit on. My plan is to use a 6v lantern battery, controlled by a simple switch and thin insulated wires with crocodile clips. If I join the circuit up, with each end attached to one end of a thin, uninsulated copper wire, will the copper wire heat up when I turn on the switch?

Thanks ahead of time

 

[Spectre694]

You will get a little heat ya. Make sure your "element" is actually a thinner gauge than your other wires though.

Don't expect much though it's not much of a power supply and copper doesn't make a great element (low resistance).

 

[little_me]

in theory, yes?
in practice, the copper wire should be quite thin if you want it to heat up to noticeable degree or the battery would need to be capable of supplying a quite a LOT of current. (quite unlikely)
Without extra things to regulate the current, you would end up with either burnt battery or copper wire that burnt through and cut itself.

Edit: or you could google a bit:
https://answers.yahoo.com/question/index?qid=20100613164934AA3H2Z1
http://www.rapidtables.com/convert/electric/Joule_to_Watt.htm

and remember, I=U/R so.. resistance of your wire will mean a lot as far as current goes. (planned wire will likely end up being like 0.1 to 0.05ohm meaning current of 60A to 120A (on 6V battery) meaning that battery will melt before the wire will.

 

[Kurdain1]

Get yourself a small incandescent bulb of the appropriate voltage. You have a self contained heating element right there, you can also use a resistor sized where it gets hot but doesn't burn up. You'll need to use Ohms law and calculate the wattage of the resistor (and thus the max heat dissipated), voltage and current required.

Are you looking for something to just get warm as a proof of concept for an assignment or something or to actually heat up something?

 

[RobotLizard]

Thanks everyone for the replies,

Are you looking for something to just get warm as a proof of concept for an assignment or something or to actually heat up something?

I'm looking for the wire to heat up, as i'm trying to make a Styrofoam cutter like the one in this video:
https://www.youtube.com/watch?v=N2n_EbRzZ0g
In the video he uses a mains power supply with a battery backup, and some wiring with dimmer switches and a transformer. I'm not great with DIY so was hoping to bypass the need for transformers and complex wiring by just using a simple crocodile clip circuit straight from the battery. Also he doesn't use copper wire, but it was recommended to me as a substitute to what he uses as I couldn't find any.

the copper wire should be quite thin if you want it to heat up to noticeable degree

Is 0.125 mm thin enough?

Without extra things to regulate the current

What do you suggest?

Edit: how about something smaller scale like this:
https://www.youtube.com/watch?v=FEMZZWjRDdw
It uses a small amount of nichrome wire and 2 AA batteries instead

 

[little_me]

Well, the main reason he uses said transformer and dimmer and all is because said battery will NOT be capable of supplying enough power for decent amount of time. Decent amount of time is of course relative.

That aside, said 0.125 would be thin enough but.. compared to what was used in video, copper tends to be softer and stretch more, both of which are not desired qualities in the application it is aimed at. It would likely work for a while though.

The video guy used the dimmer to limit the voltage and at same time, current which translates also to temperature.

Since we can assume that resistance of said cutting wire stays approximately same. U/R=I and if you lower U (voltage) and resistance stays same (R) you get less current.

There are not really all that many places you could or should take shortcuts on in that video. Only difference is that you would not need as fancy transformer as he had or 3 state switch to get 0V/6V/16V output. (effectively off/low/high settings)
Having on/off switch would be advisable though in case things go wrong.

Edit: The first video is pretty much as good cutter as you can make without buying one from market, built for more than toy/amusement use that the second video shows.

 

[RobotLizard]

Ok new plan:
Use thin, 0.559mm nichrome wire (http://www.ebay.co.uk/itm/Nichrome-Wire-Resistance-Nickel-Chrome-Heating-Element-Hot-Cutting-Various-Sizes-/251550106470?var=&hash=item3a918e0366:m:mwLLt5nI5YsX9_bf7oqQpTQ)

Connect this to four AA batteries in a holder (http://www.ebay.co.uk/itm/AA-AAA-9V-PP3-Battery-Holder-Connector-Enclosed-or-Open-with-Switch-/281526522654?var=&hash=item418c49d31e:m:mEJysrPszTERc5fcpbXpJtg)

Connect this to a simple on/off switch (http://www.ebay.co.uk/itm/261385250255) (I like this one cos it looks coolest)

The plan: the batteries heat up the thin wire enough for it to cut through thin (5/6mm) foamboard.

Will this work?

 

[little_me]

Provided you keep changing batteries as needed, yes, it will quite likely work just fine.

 

[RobotLizard]

Provided you keep changing batteries as needed, yes, it will quite likely work just fine.

Awesome thanks a bunch everyone