Technical data

D Sound module USM-RC-2
16 BEIER-Electronic 01.03.2012
The switched voltage at the outputs (if 100% intensity) is always as high, as the
supply voltage of the sound module. For example if the sound module is supplied
with 12V, only lamps with 12V should be connected. If you want to connect LEDs,
series resistors are always required. In addition attention must be paid at LEDs to the
correct polarity. The series resistors for the LED’s are depended on the supply
voltage, the LED-color and the LED-current. Modellers familiar with electronics will
certainly be able to calculate the ideal value for the models’ LEDs, but everyone else
should refer to the table below, which shows the resistance values required for
standard LEDs (approx. 15mA rating):
Supply voltage Series resistor
6V 270 Ohm
7,2V 330 Ohm
8,4V 470 Ohm
9,6V 510 Ohm
12V 680 Ohm
If multiple LEDs are connected to one output (e.g. front and rear direction indicators),
it is always better to use separate dropping resistors than to wire the LEDs in series.