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Voltage for NiChrome? Answered

Will 2.5 volts be enough to heat a small segment of NiChrome wire up to/over 100 C? If it helps, the power is coming from a 8.1 kJ 2.5v 2600 F super capacitor which can unload very quickly.

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steveastrouk
steveastrouk

10 years ago

2.5 Volts, into 1.4 Ohm, is 2.5^2/1.4 W, or 4.4W., or 4.4J/sec. That will last a fair time - 2600 J/ 4.4 J/sec= 590 seconds, or 10 seconds shy of 10 minutes.

How HOT it will get is complicated, but if you assume its completely lossless - you can work out how long it will take to warm up, if you know the thermal mass, which is the mass x specific heat capacity, and you assume a rise in temperature of 100 C then Joules needed = mass x SHC x 100.

Steve

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VikasM51
VikasM51

Reply 2 years ago

6" or 8" inches

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VikasM51
VikasM51

Reply 2 years ago

8cm length of nichrome wire 20 mm and 100 degree Celsius temp required

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LiquidLightning
LiquidLightning

Answer 10 years ago

About 1cm long, 18 gauge, NiChrome, about 3-4 seconds, and 2.6 kJ.

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lemonie
lemonie

Answer 10 years ago

Should be quite achievable in energy terms, if I read the wire gauge right it'd be ~1.4 ohm per metre, giving you 0.014 ohm for 1cm.
But that means you'd need to limit current or it'll get too hot very quickly (or will it? for a single-use ignition it'd work)
Maybe some constant-current supply, but at low voltage I don't know.

L

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LiquidLightning
LiquidLightning

Answer 10 years ago

The wire won't be bare, it would be in a small amount of water.

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lemonie
lemonie

Answer 10 years ago


That makes a difference. You're really asking about heating water then -
How much water?

L

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LiquidLightning
LiquidLightning

Answer 10 years ago

No, I'm not asking about heating water, I need the actual wire to get hot, but not above 100 C. The water is just there as a coolant for it to not exceed 100 C.

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lemonie
lemonie

Answer 10 years ago


Water has a high heat-capacity, in terms of how hot things get with current water makes a big difference.
What's it for?

L

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steveastrouk
steveastrouk

Answer 10 years ago

The "2.6kJ" is almost irrelevent, because thermal mass here is insignificant.

Steve

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VikasM51
VikasM51

2 years ago

I also want to make homemade plastic sealer for kitchen with 8cm nichrome wire having resistance of 15 ohms total including switch and connecting wires etc but can't able to find the result by using 9v battries

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VikasM51
VikasM51

Reply 2 years ago

Any body can draw a circuit diagram with 9v of plastic sealer

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Kiteman
Kiteman

10 years ago

It depends how thick the wire is.

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frollard
frollard

10 years ago

depends on the resistance = amps = watts = energy, which can be used to determine the temperature change of a given weight of wire at a certain heat capacity.

ohms law