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12v dc nichrome electric heater Answered

hi friends
i want to make electric heater that could give sufficient heat with 12 volt dc battery.
how much nichrome wire in lenght should i use and how much gauge of nichrome wire should i use.
i love for your kind replies.
love u all


3 Replies

iceng (author)2018-01-17


This article has the tables you need to design a nichrome heater.

First design rule, you want to to stay well below the melting point 1400 C..

Table # 3 tells us you get 400 watts from a 22 AWG wire at 30 ohms and 120 volts that works out A=120/30 = 4 amperes of current.

Now if we want 4 amps at 12 volts the wire resistance would have to be R=V/A

R=12/4= 3 ohms one tenth of the 120v length only P=V*A=> 12 watts and that is too small !

Back to table # 3 where 1400 watts at 8.8 ohms AWG 15 which works out to A=V/R=120/8.8=14 amperes.

Power of about 9 amps at 12 volts A*V = 9x12 => about 108 watts with a new R=V/A=12/9=1.3ohms.

Now in table # 2 we see a 15 AWG nichrome wire will be about 300 C at 9 amperes..

You need to measure about 1.3 ohms of this wire use wire screws solder does not work use a threaded bolt and nut.. Don't cut until you try it and don't burn yourself !


Trial and error does it...

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iceng (author)iceng2018-01-17

Split bolt lets you connect copper wire to nichrome wire.

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