LED Connections problem

Thread Starter

ect_09

Joined May 6, 2012
180
Hey,
am confused , i design generic board where i can program MCU through programmer and can get input and output frm different ports.
but problem is that i want to connect LED in it in the start circuitry to show power is ON. i have 5V source.
when i connect this LED i get the output voltage 3.87v that is not enough for MCU.
please tell me how i connect this LED in circuit.

Regards,
 

adam555

Joined Aug 17, 2013
858
Are you connecting the LED in series with the 5v source, or in parallel? You need to connect it in parallel; and also limit the current to 20mA with a 250 ohm resister (220 ohm is the closest standard value).
 

Thread Starter

ect_09

Joined May 6, 2012
180
Are you connecting the LED in series with the 5v source, or in parallel? You need to connect it in parallel; and also limit the current to 20mA with a 250 ohm resister (220 ohm is the closest standard value).
if i have one resistor and voltage source of 5V then how can i connect it in series...

??
 
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