# power supply for heating cable

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Joined: Jul 16, 2021

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power supply for heating cable
July 16, 2021 - 11:11pm

HELP ! : )  I have no Idea how to do this. I am designing a product to be used by search and rescue teams using a drone with thermal camera.

I want to add a low voltage heating cable that can heat up to approx. 37º C around the perimeter of corrugated plastic board. The length of the heating cable would be 5 meters.

I'd like to power it with a AA battery box with on/off switch (using 4 to 6 batteries). My question is what resistance cable should I use, are 4 AA batteries enough to power 5 meters, and how do I connect the battery pack to the heating wire?

The ebay listing for the cable provided the following information that may be helpful:

• Supplied resistance: 0.3, 1, 1.4, 3, 4, 5, 8, 10, 15, 20, 25, 40 Ohm/m, please choose according to your need.
• Diameter: 1.2~1.4MM

How to calculate the power:

• Power=Voltage*Voltage/(Resistance*Length)
• For example:
• Using 2m 5 Ohm/m cable on 12V, the power is:
• 12V * 12V / 2 meters * 5 ohm = 14.4W
• Using 15m 1.4 Ohm cable on 24V, the power is:
• 24V * 24V / 15 meters * 1.4 Ohm=27.4W

I really appreciate any help, thanks for your time!

Roger

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Joined: Feb 12, 2018

Replies: 696

Power = I(2)R.

That means a 5 ohms cable will draw current from a 12V battery will be = 2.4A

The wattage of heat will be dissipated on the wire = 2.4A x 2.4A x 5 =  28.8Watt