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DIY Stompboxes => Building your own stompbox => Topic started by: gmr1 on April 29, 2009, 07:23:05 AM

Title: Adding resistance to negative leg of LED
Post by: gmr1 on April 29, 2009, 07:23:05 AM
I've seen some switch diagrams that do this. Any disadvantages to this? If I'm using 8.2K when wiring using the positive side, when I switch it to the negative, should it remain the same? I like the idea, as it allows me to add the LED resistor to the switch, making it easier to solder...
Title: Re: Adding resistance to negative leg of LED
Post by: ~arph on April 29, 2009, 07:48:12 AM
no difference
Title: Re: Adding resistance to negative leg of LED
Post by: gmr1 on April 29, 2009, 07:49:09 AM
Quote from: ~arph on April 29, 2009, 07:48:12 AM
no difference
Cool, thanks. I had assumed that, but wanted to make sure.
Title: Re: Adding resistance to negative leg of LED
Post by: John Lyons on April 29, 2009, 12:13:00 PM
Yeah, either side is fine.
I've made pedals and after I have everything put together
wanted to change the LED brightness ti match two LEDs
I put a little resistance on the neg side and that balanced the
brightness. You can use resistance on either side.

John
Title: Re: Adding resistance to negative leg of LED
Post by: Nitefly182 on April 29, 2009, 12:50:39 PM
Yup its about the voltage flowing through the led, not just into it.
Title: Re: Adding resistance to negative leg of LED
Post by: R.G. on April 29, 2009, 02:19:34 PM
Quote from: Nitefly182 on April 29, 2009, 12:50:39 PM
Yup its about the voltage flowing through the led, not just into it.
It's about the *current* flowing through the LED.

A hard to believe axiom is that the currents and voltages of any two electronic components in series is not affected by the relative order of the two parts.