HELP

phantombrit

Jul 3, 2012
1
I would like to make my own lighting set for my boat trailer using LED's that are integrated into the actual metal. I found out how to wire LED's using resistors and the Om's law for my 9 year old son. So my question is: Do I need a DC-DC converter , A voltage regulator on my 12v supply.
So can someone please give me a nudge in the right direction so I can achieve my goal

P.S looking on the web my son has asked me to buy a simple electronic circuit , he can solder so can anyone recomend and fun/cheap one

many thanks

john monks

Mar 9, 2012
693
An LED, for practical purposes, run at a constant voltage, usually around 2 volts. A typical forward current is about 20mA. If this is for a boat trailer, I would think this is being pulled by a vehicle that uses a 12 volt battery that actually supplies from 13 to 14 volts. So say the voltage is 14 volts and the LED runs at 2 volts you take the difference voltage and calculate a series resistor, R=(Vbattery-Vled)/Iled. You might want to start with a 620 ohm resistor. Your son may want to experiment with LEDs and a 9 volt battery with some resistors then he can explain to you how this works. I am not sure what you mean by integrated into the actual metal but there are all kinds of LED strips you can experiment with.

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
for practical purposes

I would prefer to say "for the purposes of calculation".

My only other comment would be to make sure that your calculations do not yield a very small value resistor (say 100 ohms or less). The problem with car electrics is that the voltage varies significantly, and too low a calculated resistance means your string of LEDs is going to be subject to greater changes in current as the voltage varies.

Google "LED calculator" for plenty of pages that will assist you in calculating (or at least confirming) your choice of resistor.

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