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DIY Stompboxes => Building your own stompbox => Topic started by: Hupla on September 29, 2009, 10:41:20 AM

Title: LED's without current limiting resistor.
Post by: Hupla on September 29, 2009, 10:41:20 AM
Ok so say if the voltage drop for the LED is 1.6v and thats all Im putting across the LED, does it still need a resistor?
Title: Re: LED's without current limiting resistor.
Post by: petemoore on September 29, 2009, 10:45:59 AM
  Yup, the easy way is to use a current limiting resistor.
  To control the flow of current using voltage alone would be more difficult at least.
Title: Re: LED's without current limiting resistor.
Post by: Hupla on September 29, 2009, 10:55:13 AM
But all that's available to me is 1.6v. If I put a resistor there the voltage will be too small and the light very dim, would it not?
Title: Re: LED's without current limiting resistor.
Post by: darron on September 29, 2009, 11:02:18 AM
if you are supplying the LED with only 1.6V then you won't need a limiting resistor, no. you'd only need the limiting resistor if you are supplying it from the 9V that stomp boxes usually run on. what is the source of the 1.6V though?
Title: Re: LED's without current limiting resistor.
Post by: BAARON on September 29, 2009, 11:10:18 AM
And what are you trying to do with the LED?  What is it for?
Title: Re: LED's without current limiting resistor.
Post by: ayayay! on September 29, 2009, 11:12:01 AM
Pete's right.  You'd still want to control the current to mitigate/stabilize power consumption.  A small resistor between 100 - 300 would probably do.  
Title: Re: LED's without current limiting resistor.
Post by: Hupla on September 29, 2009, 11:17:52 AM
Its not a stomp box. Tis for a project in college. Were using a spdt switch to switch between 2 different potential dividers of 1.6v and -1.6v. Its to move a motor by a set amount. We have to put in an led for each to show which way its going, and the only way I can think of doing it with a spdt switch is to have it coming off the 1.6v after the switch. If you understand what I mean.

I just asked the question here cause I couldnt find the answer else where, sorry if im not meant to.