I have a dc generator from a windturbine that can output about 28-30volt when handcranked. My idea where to take that power when cranked and heat up a coil of ex. Nichromewire. If i put each polarities of the generator to each ends of the coil i get too much resistent in my generator so i can't turn the crank. Can someone help me arround this problem (im a noob at electricity and electronics). The idea of this project is to have a "handcranked lighter" for outdoor survival purposes so i need the wire/coil to get glowing hot. If i need to make some circuit please explain or sketch me one.

Thanks in advanced.

 

Raise the coil resistance...or get a bigger crank.

 

While this sounds like an interesting thing to build, something like this is likely to be a better approach as it doesn't require electricity and works when wet.

If you want to continue your direction, use a nichrome wire temperature calculator to figure out temperature, volts and current. Look to e-cigarettes/vapes for inspiration. But I would probably pursue creating sparks via a piezo,

 

While this sounds like an interesting thing to build, something like this is likely to be a better approach as it doesn't require electricity and works when wet.

If you want to continue your direction, use a nichrome wire temperature calculator to figure out temperature, volts and current. Look to e-cigarettes/vapes for inspiration. But I would probably pursue creating sparks via a piezo,

Yea iv'e already got several flint and steel firestarters, just want to try different things to make fire and that are long lasting.

 

I have a dc generator from a windturbine that can output about 28-30volt when handcranked. My idea where to take that power when cranked and heat up a coil of ex. Nichromewire. If i put each polarities of the generator to each ends of the coil i get too much resistent in my generator so i can't turn the crank. Can someone help me arround this problem (im a noob at electricity and electronics). The idea of this project is to have a "handcranked lighter" for outdoor survival purposes so i need the wire/coil to get glowing hot. If i need to make some circuit please explain or sketch me one.

Thanks in advanced.

The "voltage" you measure with your hand crank is kind of meaningless if it is not connected to a load. The important part is, how much POWER you van get. That is, once you have a load attached.

You can arm/body crank a big crank and make about 750 watts for a a few seconds. A small hand crank about 25 watts for a few seconds but not while holding something small in any stable position to light a fire. So let's focus on something like 10 watts. We'll assume you can make a coil out of nichrom to concentrate the heat of that 10 watts into a small space that can hold the heat rather than quickly dissipate it to the air (you want an anti-radiator or anti-heat sink). Something like a car cigarette lighter (which are actually about 120W and need 10 to 20 seconds to heat up before they can actually start some paper and leaves smoldering with a near-perfect airflow to cause ignition.

In other words, this is a long way to say, a hand-cranked firestarter would exist if it was easy.
You'll have to find a power level that you can actually generate (don't worry about voltage - your hand / arm doesn't care about voltage it cares about power (Volts x amps). You can worry about optimizing weight and safety later but focus on power now.

If someone wants to carry a hand cranked generator, they may also be willing to carry some steel wool that makes starting a fire easier. Lots of system design issues can be used to make this unit smaller, lighter, easier. For example, a 9v battery.

 

Yea iv'e already got several flint and steel firestarters, just want to try different things to make fire and that are long lasting.

An Energizer Ultimate Lithium battery can sit, unused, for 20 years without losing charge. If you need something in a prepper shed, I would stock up on those.

 

Energy! That's what you're converting; energy. Physical (muscle) energy into heat energy. You can't create or destroy energy you can only convert its form. In this case, the energy required to make the NiChrom wire hot is more than your muscles can produce.

There's a video of an olympic cyclist driving a generator to make toast. He couldn't do it. The simple act of making toast takes a lot more power than a human can make. I'll see if I can find the video, but it's been posted somewhere in this forum before.

 

As you've discovered, as soon as you try to extract energy from your generator it fights back.

just want to try different things to make fire and that are long lasting.

I think a hand-cranked generator would not be long-lasting, especially in harsh environmental conditions.

 

Just saying Nichrome Wire isn't going to work. What size Nichrome Wire? Wire is sized by gauge and the resulting resistance per a length is a function of the gauge (diameter) The voltage / resistance will give you the current. Obviously your voltage and current demands exceed what you are capable of cranking out (literally). This is a resistance chart based on gauge in AWG if you are not acustomed to AWG find another chart. All of this assumes you wish to drag around a hand crank generator to start a fire.

Ron

 

Energy! That's what you're converting; energy. Physical (muscle) energy into heat energy. You can't create or destroy energy you can only convert its form. In this case, the energy required to make the NiChrom wire hot is more than your muscles can produce.

There's a video of an olympic cyclist driving a generator to make toast. He couldn't do it. The simple act of making toast takes a lot more power than a human can make. I'll see if I can find the video, but it's been posted somewhere in this forum before.

Hmm intressting..but lets say i want to lift a car and carry it from point a to b it would be impossible..unless i take it apart at point a and reassemble it at ponint b..so can i store that energy from my generator and when i have enough i use it all in once on a coil?

/sry if my english is bad^^

 

If you can accumulate the energy over a long enough period and use/discharge it in a short enough period, yes. However, details matter here. I still think you are better off making sparks.

 

Admittedly, yes, you can store the energy and then release it in higher quantities. But I think you're going to have to charge a battery sufficiently, otherwise, using something like a capacitor (which you did not say) would not hold sufficient energy to do the job.

Also, you're not making toast. You're just making a locally hot point to light a fire. That still might require more energy than you think. Cranking such a device may prove difficult. It's probably buildable, but the question revolves around practicality.

I've seen fires started just using a 9 volt battery and some steel wool. I'd think that's a bit easier to transport. But in case of emergency and all you have is a hand cranked generator and a nichrome wire - you can probably manage a fire. Varying the length and diameter of the wire, you can probably optimize something. However, a smaller wire will be fragile and prone to breaking. There's up sides to your project and down sides. But I'm sure you can bodge something together.

 

Hmm intressting..but lets say i want to lift a car and carry it from point a to b it would be impossible..unless i take it apart at point a and reassemble it at ponint b..so can i store that energy from my generator and when i have enough i use it all in once on a coil?

/sry if my english is bad^^

The problem is you actually have to let the stored energy out at an optimized rate. Burning a stick requires the stick to be heated to s high enough temperature that the wood fiber starts to decompose and give off methanol. Once methanol is emitted, at a high enough rate to make a combustible air/methanol ratio, and that it can be burned long enough to keep heating more wood.

A quick flash of heat does not make the process work because wood is a slow rate of thermal conductivity. As I said above, if it was easy, a hand cranked fire starter would be on the market.

 

If you can accumulate the energy over a long enough period and use/discharge it in a short enough period, yes. However, details matter here. I still think you are better off making sparks.

hhm perhaps..well i just found this https://www.amazon.com/SE-FL3139-Dynamo-Starter-Crank/dp/B008JRRBJY about same idea but just for firestart. How does it work

 

The problem is you actually have to let the stored energy out at an optimized rate. Burning a stick requires the stick to be heated to s high enough temperature that the wood fiber starts to decompose and give off methanol. Once methanol is emitted, at a high enough rate to make a combustible air/methanol ratio, and that it can be burned long enough to keep heating more wood.

Definitely true. However, when camping, one night we had a fire going. We let it smolder through the night and the next morning there was not enough heat energy to light kindling. So I took a bed of pine needles and laid them over the embers and they started to smoke. With kindling on top of the pine needles, I lifted the needles up just enough to get some oxygen in there and they erupted into flame. The kindling caught quick enough and I was able to throw small branches on the fire to cook breakfast. And it had been drizzling the whole time we were there (8 days) (miserable trip in deed).

You don't need to start a log on fire. Tissue paper can then catch news paper can then catch kindling then catch small branches then logs. Starting a fire is not a straight forward thing. It starts with an ember that needs to be coddled into a bigger ember until you have a fire going. Rubbing two sticks together - I've never even tried that - but it's also doable. Takes a lot of human powered energy. I like simple. Strike a flint, light some gas, put it to some paper under kindling - and I'm a happy camper.

OK, you can generate a fire. You can also spark a fire. You can also carry a lighter. Or matches. How much gear do you want to pack in and out of a camp sight?

 

hhm perhaps..well i just found this https://www.amazon.com/SE-FL3139-Dynamo-Starter-Crank/dp/B008JRRBJY about same idea but just for firestart. How does it work

Did you read the reviews? 7 reviews and 39% of them were one star. Only 9% were 5 stars.

Tiny element - which is fragile. Probably one complaint was that it worked for 1 1/2 seconds before the fire starter element burned out. Probably was broken by the user, which highlights how fragile a heating element can be when made small enough to be human powered.

[edit] one person in seven claims to have started a fire with it. Do you like the odds?

 

OK, you can generate a fire. You can also spark a fire. You can also carry a lighter. Or matches. How much gear do you want to pack in and out of a camp sight?

This is why I think (and suggested above) the best bet is to make sparks. Lowest amount of energy needed.

I still think a flint striker (and maybe magnesium shavings) is the way to go.

Back in my camping days I'd carry lint from a dryer (after drying cotton towels) in a zip lock bag. Man that stuff starts up easy. One spark was all it needed. Wowed my camping buddies with how fast we got the fire going.

 

Definitely true. However, when camping, one night we had a fire going. We let it smolder through the night and the next morning there was not enough heat energy to light kindling. So I took a bed of pine needles and laid them over the embers and they started to smoke. With kindling on top of the pine needles, I lifted the needles up just enough to get some oxygen in there and they erupted into flame.

Where is the "however" in your story?
The pin needles (containing volatile terpene oils) were preheated, giving off enough fuel to make a combustible fuel/air mixture long enough to heat the rest of the needles and vaporize the rest of the oils and then enough excess energy for long enough to heat the kindling and start it a blaze.

My definition of "all at once" is a spark and the whole point of this story is that flint sparks take a lot of skill and preparation so the OP is looking for another option.

 

Hmm intressting..but lets say i want to lift a car and carry it from point a to b it would be impossible..unless i take it apart at point a and reassemble it at ponint b..so can i store that energy from my generator and when i have enough i use it all in once on a coil?

/sry if my english is bad^^

Well figure it this way. One Horsepower is about 746 watts of power. That is less any consideration for loss as nothing is 100% efficient. Everything always will revert back to power. With that in mind how much power or energy will be required to lift and move an object, any object be it a car or 2,000 Kg weight? Next enter the problem Gopher points out, we need to release the stored energy in a controlled method and again there will be loss.

Back on the subject what is the efficiency of making heat using electricity. How much energy converted to heat using a nichrome wire will I need to start a small fire or for that matter light a cigar?

Ron

 

Go back to the nichrome calculator.

5mm of 40 ga wire at 1000F will require 213 mW - 430 mA at 0.4955V. Not sure if the temperature is too high and not at all sure how long that needs to be sustained.