search

fachat / cbm_ultipet

GNU General Public License v3.0
1 stars 0 forks source link

Does R22 need to be 390Ohm? #7

Closed fachat closed 1 month ago

fachat commented 4 months ago

R1.1A - LED current limiting resistor.

fachat commented 1 month ago

For the chosen (as it seem not low power) LED it should actually be 150 Ohm...: 5V VCC minus 2V Vf is 3V over the resistor, for 20mA current that gives 150 Ohm.

I could probably use a low power LED if it is same price or less. Should also be considered for the shift lock LED.