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Originally Posted by Jp7
25c for a resistor? I buy 100 of them for $1.41.
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True, but I thought this guy was only working on one truck, not hundreds. My mistake... I apologize.
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Originally Posted by Jp7
A good 12V regulator costs less than 1$.
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But, since excess current is what destroys a diode (Light Emitting or otherwise), a simple resistor is what will limit the current to a safe value. And as you explained, a resistor is ˘heaper than a regulator and its circuitry, especially when purchased in quantity.
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Originally Posted by Jp7
A regulator will prevent voltage spikes from hitting the diodes where a resistor will only limit current based on the pressure it is fed. Most pods I've installed (100's of them) are already internally limited so that 12V keeps them in the nice flat linear portion of the diodes response curve. The regulator will do a much better job of preventing thermal runaway.
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The resistor passes current (in Amperes or milliamperes) based on the VOLTAGE impressed across it; and the voltage in volts multiplied by the current in amperes dissipates power expressed as heat, which is measured in watts.
All automotive electrical systems since the Model T have been controlled by a voltage regulator; in the 1930's the regulation was done manually by adjusting the brush on the generator. Newer cars had automatic regulators on their generators; in the 1960's alternators replaced generators, and shortly afterwards, the regulators were electronic, internal to the alternators. These systems, paralleled with a hefty 12 volt battery together effectively limit the system voltage applied to the fella's Glo-Pod. And if the car's regulator fails, or if the battery gets inadvertently disconnected while the engine is running, the series resistor acts as a passive fail-safe device, protecting the life of the Glo-Pod.
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Originally Posted by Jp7
Also - this is how the OEMs do it.
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He's not an OEM, just a hobbyist.