[brschmid]

I have a 2.1V 20mA led i am going to be using on my latest amp, but i also want to use a lighted switch that has a led built in. if i run both leds off the same points on the board, will it cause a problem?

 

[kevin gilmore]

If you are putting the led's in parallel without seperate
load resistors you will find that only one will light.
Either use seperate resistors for each led, or put the
led's in series.

 

[brschmid]

will that affect the output brightness of each?

 

[MLOFI]

Quote:

Originally posted by brschmid will that affect the output brightness of each?

Only if you series the led's. Best to parallel with a resistor with each as suggested by Kevin.

Marco

 

[brschmid]

ok, but the LED's will be run off the same 2 points on the PCB. there is a resistor in place, but it is for the only the designed LED., i can't add a second resistor.

 

[MLOFI]

Quote:

Originally posted by brschmid ok, but the LED's will be run off the same 2 points on the PCB. there is a resistor in place, but it is for the only the designed LED., i can't add a second resistor.

Okay, gotcha. Perhaps you could jumper RLED and then solder the resistor inline with each led?

 

[rickcr42]

Quote:

i can't add a second resistor.

if you can add a second led then you can also add a second resistor

you already need to do a takeoff from the board

and if not comfortable with that do like kevin said and go for a series connection off the switch

ohms law is your friend

 

[brschmid]

Quote:

ohms law is your friend

i have never been very good with that one.

I guess i could just desolder the LED and put on on each.

for right now( testing purposes) i am going to just use the led on the switch, then probably add the second.

thanks