wiring leds

[desitdt 10+ year member]

Im putting leds in my door switches to change the color to blue. However after doing one door i realized they were WAY to bright and went back and used 2 leds in series connected to one resistor. Shouldnt this decrease the brightness of the Leds? I have one switch with one resistor per led and one switch with 2 leds per resistor and they are the same brightness. can someone help me out here?

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[All_Logix 10+ year member]

If you series LED's and resistors your current that passes through them will be the same through each component, all that resistor is doing is lowering the voltage...since LED's are diodes they rely on current intensity as to the intensity of the light emitted. Try this parallel the LED's and the resistor, that will maintain the voltage across the each component which is good for them and cut the current down, lowering your light....in theory

 

[desitdt 10+ year member]

Is that not completely backwards? running them in parallel would give them all the same lowered voltage of the circuit after the resister. You can run 4 3.4 volt leds togeather in series without even usuing a resistor (technically). So wouldnt wiring them in parallel WITH a resister lower the voltage even further?

 

[All_Logix 10+ year member]

Let me explain it this way...if you start with 12 volts...you can parallel 100 LED's and they will all have 12 volts across them, just different amounts of current. now if you put a resistor in before the parallel of the LED's you will lower the voltage that goes across the LED's so if you start with 12 volts, lower it to say 9 volts after the resistor, then every LED will have 9 volts across it....