tams
elektronik
English
FD-R Basic 2
Parallel connection of LEDs
Alternatively, you can connect several LEDs in parallel, each via a series
resistor of its own. The current consumption is max. 20 mA for all LEDs,
depending on the series resistor´s value. The maximum number of LEDs to
be connected in parallel results from
maximum current at the output
-
sum of the current consumption of all LEDs
> 0
Advantageous with this solution is that the LEDs already lighten when
their forward voltage has been reached (2 to 4 V, depending on the
fluorescent colour), which makes this solution suitable for analogue
mode. Disadvantageous is the high current consumption.
The formula for the calculation of the resistor is:
required R
V
[Ohm] = ( U
B
[V] – U
F
[V] / (I
F
[mA] x 0.001)
U
B
= operating voltage (peak value) | U
F
= forward voltage of the LED
I
F
= current with max. luminosity
In order to save current, you can limit the LEDs´current consumption to
10 mA, which normally does not cause a visible loss of luminance.
Fig. 2: Connection of LEDs
and accessories to the funtion
outputs (examples)
AUX1: lamp
AUX2: parallel connection of
LEDs
AUX3: serial connection of
LEDs
AUX4: combination of parallel
and serial connection of LEDs
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