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Sasha84 #1 11/04/2011 - 11h48

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Registered on : 26/06/2008

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Hi.
I am using Heat-shrink tubing on the wires connections and warm it up with a lighter.
After I connected resistor with wire, cover connection in heat shrink and started warm it up i noticed that resistor is getting very hot.
And I am not sure will it have any effect on my resistors, I read that high temperatures might shorten the life span of a resistor or change it resistance but i am not sure how high is too high.

So everything working for now but just to be sure, maybe there is someone who have any experience or knowledge on topic.
Maybe instead i should use simple insulating tape, it wont be so neat and durable but better in longer perspective.
dewey1 #2 11/04/2011 - 21h40

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If you are using one resistor with 3 volts and have your LEDS in parallel as you suggested in your other thread you may have problems.
This is a very poor design to use and is not recommended for many reasons.

You should use 3 separate resistors if you plan on 3 LED parallel configuration.
With 22 ohm resistor per LED is 68 mA. The actual power is about .1 Watt per resistor.
.068 x .068 x 22 = .102 W

Double actual power for minimum wattage rating of the resistor. So a 1/4 to 1/2 W would be fine.

edit for wrong information.
Edited by dewey1 on 12/04/2011 at 04h39.
Sasha84 #3 12/04/2011 - 04h01

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I know if you check my previous post you will find that i corrected my mistake and I'm using 3 separate resistors now.
dewey1 #4 12/04/2011 - 04h37

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So you are stating each resistor is hot?

I guess what is your question now? You state one resistor is hot.
What is each resistor value and wattage?
Sasha84 #5 12/04/2011 - 05h00

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Ok sorry I think i screwed explanation with my lame english  :rolleyes:
The reason resistors getting hot is because I warm heat-shrink with a lighter and resistors are getting really hot from its flame.
So lets put it like this.

--------------------============---\\\\\\\\\\------------------
  Wire^                   ^Heat-shrink          ^Resistor

When i warm up heat-shrink with a lighter resistor getting quite hot and I am worried a bit how will it affects my resistors in longer perspective.
Shorter life span, changes in resistance etc.
tracker #6 30/04/2011 - 12h30

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Registered on : 09/10/2010

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Don't worry. If you do it quickly, nothing happens. But resistor itself can reach high temperatures when operates close to maximum wattage rating. That's why you need to use resistors with higher wattage. This info can be found in datasheet.
srinivasan #7 18/05/2011 - 15h06

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Posts : 6
Registered on : 11/02/2011

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So you are stating each resistor is hot?

I guess what is your question now? You state one resistor is hot.
What is each resistor value and wattage?



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