# Dew Strip

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Following this guide I made a dew strip yesterday for my Tal 100rs. The strip measures 15" long I used bare copper like the guide says and 20 x 0.6 watt 330 ohm resistors. then attached 6 amp insulated cable to one of these

It feels a lot hotter than my nichrome strip. Have I messed up having a bit of trouble with the calculations thanks.

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Let's see, you have 20 330 ohm resistors connected in parallel:
1/Rtot = 1/R1 + 1/R2 + ...
So Rtot = 16.50 ohm

P = V^2/R
I'm assuming you're powering using 12V so
P = 8.72 watts total or ~ 0.6 watts per cm.

I think nichrome is around 0.3 watts per cm so your home-made one should be twice as warm.

How were you powering it?
Note the website says:

Quote

Also, this type of heater can not be used without a controller as it would get too hot.

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Thank you that is probably why I was powering it from one of these

Looks like I am going have to power it from the battery instead, thank you so much.

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There's no reason I can think of why you couldn't plug the dimmer into the power adaptor the same way you would to the battery if you wanted to.

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Thank you thank you just worked that out works perfectly now brilliant.

Edited by wookie1965
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Well done Paul

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Just now, mapstar said:

Well done Paul

Cheer`s Damian means a lot from you.

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On 18/10/2017 at 12:18, wookie1965 said:

I used them when I installed my cctv and cat5 cable

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