Re: is there a way to increase the light of an LED with a dial?



If the batteries drive the LEDs directly, then there's no way that you can
burn them out by turning the pot all the way up -- in either case, the net
resistance in series with the LEDs is zero.

If there's a dropping resistor between the battery and the LEDs, the same is
true, if you leave the resistor in place.


.



Relevant Pages

  • Re: very simplistic potentiometer question
    ... > I've figured out already that without a resistor that LEDs last about .2 ... a minimum voltage to light. ... Without the current limiting resistor ... >5 seconds I'd like to add a pot to control the brightness. ...
    (sci.electronics.basics)
  • Re: Cant get enough current for 1W Luexon LED even without resistor
    ... resistor but still only about 100ma current. ... want to be thinking in terms of voltage. ... life from any high power LED, is to pulse drive it. ... The level of these that some high power LEDs can ...
    (sci.electronics.repair)
  • Re: Cant get enough current for 1W Luexon LED even without resistor
    ... Then I tried without the resistor but ... the LED I have to raise the voltage to about 11V and of course I ... LEDs for a long time, and never suffered a problem with a switch-on ... max forward current quoted in specs, is for a short duration pulse. ...
    (sci.electronics.repair)
  • Resistors for LEDs: the real answer
    ... First of all, while non-electronics types refer to the resistor in this use as a "dropping resistor", that's not really technically accurate: whats actually going on is that you're making a voltage divider network with a resistor in series with the LED. ... By putting a resistor in series with the LED, you're dividing the 24 volts between the resistor and the LED, because the whole idea is to make sure that the LED doesn't get too many volts and blow. ... Turning to my handy-dandy Jameco catalog, it appears that most garden-variety LEDs are rated at about 2 volts, some more, some less: close enough to be no never mind. ...
    (rec.models.railroad)
  • Re: Resistors for LEDs: the real answer
    ... while non-electronics types refer to the resistor in this ... whats actually going on is that you're making a voltage divider network ... Obviously, if you just put the poor LED across the 24 volts, ... the great majority of LEDs are rated at 20 mA; ...
    (rec.models.railroad)