To use LED's with the Mini Commander LC1 and LC2 outputs, you will need
a series resistor and diode connected to the LED. The
MiniCommander outputs 1/2 of the supply voltage on LC1 and LC2. Each output has a
different polarity, thus choose the circuit above depending on
what output the LED is attached to.
The series resistor is calculated as follows:
Example 1:
Source Voltage = 9 volts
Voltage Drop = 3.6 volts (Typical for a blue or white LED)
Desired Current = 20 milliamps (a typical value for White)
To calculate the resistor you need:
(9  3.6) / ( 20 / 1000 ) = 270 ohms
Example 2:
Source Voltage = 9 volts
Voltage Drop = 1.4 volts (Typical for a Red LED)
Desired Current = 15 milliamps (a typical value for Red)
To the calculate the resistor you need:
(9  1.4) / ( 15 / 1000 ) = 510 ohms
