# Designing a homemade electric lighter

#### theonecalledultra

Joined May 13, 2014
7
I'm trying to make an electric lighter ( like this http://imgur.com/a/wg8q7) using the framework of this guide.
http://www.instructables.com/id/Make-a-battery-powered-soldering-iron/?ALLSTEPS
except mine will have a few more feature and the soldering tip will be replaced with nichrome most likely.

Theres is just a few things that I am stuck on

-First, Is nichrome the best material to use as the heating element?
Assuming we do use a wire heating element the length of the wire will be 1.5-2 inches long, what would be the best gauge? any other details about it?

-Second, I need the heating element to stay at a constant temp of at least 500 Fahrenheit
What type of circuitry would I need to accomplish this, what if i wanted to to be able to control the amount of power?

-Third, what would be the best batteries to use for this? I was hoping to be able to use 4xAAA or 3AA

#### Brownout

Joined Jan 10, 2012
2,390
Nichrome is typically used for heater elements. If there is a better material, I don't know what it is. There are lots of things to consider when selecting the gauge. First, the resistance of the wire is related to its gauge. Second, the ability to withstand the high temperatures without breaking are also related to the gauge. Once you know the voltage and power supplied form the source, you need to match the resistance of the wire to the source. And, you need to calculate the temperature of the wire using the material's specific heat.

That's only how to get started, there are other things to consider. I don't have an answer at the ready, because I would need to go through the whole process myself. One approach is to pick some starting values, go through the calculations, and then refine your choices until you have your desired results.

Sorry for such a generic answer. I don't think there is a simple one, though someone may come along and prove me wrong.

#### theonecalledultra

Joined May 13, 2014
7
Thanks brown but I still don't have much of an idea of what to do next lol

Mind helping me start? lol
How do I calculate the voltage and power of 2AA batteries?

#### Brownout

Joined Jan 10, 2012
2,390
Each AA battery is ~1.5V. IDK what the maximum power is, but the more power you extract, the shorter battery life. So I guess you start by looking up discharge curves for different AA batteries, and decide how much power you can use for you target battery life.

#### theonecalledultra

Joined May 13, 2014
7
thanks for the tips,

Would you say this would be a relatively easy project to finish?

#### theonecalledultra

Joined May 13, 2014
7
LOL hey ronv

yeah I really need to figure this out, so im trying to get all the help i can

#### Brownout

Joined Jan 10, 2012
2,390
thanks for the tips,

Would you say this would be a relatively easy project to finish?
No I would not. It might be best to start with a working design and experiment from there. Otherwise, you would do the math iteratively.

#### theonecalledultra

Joined May 13, 2014
7
So Lets say the wire
has 11ohms resistance total needs 1.15watts and 0.30amps to reach 600farenheit

what would i do from there?

#### Brownout

Joined Jan 10, 2012
2,390
Your gonna need to supply 323mA. Now you look up battery data and see how you're gonna do that.

#### theonecalledultra

Joined May 13, 2014
7

I found this site http://www.powerstream.com/AA-tests.htm but im having trouble relating the values. So does this mean one AA battery would last about 1.5 hours at ~350mA?

again thanks for the help, and for being patient with me, I have no experience whatsoever in this field.

#### ronv

Joined Nov 12, 2008
3,770
Yes, pretty close. The higher the discharge rate the lower the amp hours because some power is lost as heat.