Just like in transistor biasing as discussed yesterday LEDs(Light Emitting Diodes) too are very
sensitive to high currents. A resistor
when placed in series with the LEDs
regulates a proper flow of current
To calculate the value
of a series LED resistor, the
following formula may be used:
R = V –( N.V ) / I
- R = Series LED resistor
V = supply voltage
N = number of LEDs in series
V(LED) = forward voltage of the LED used and
I = current through the LEDs (10mA optimum).
These resistors are generally of low values so that the over all performance of the circuit is not affected.
written by Anthony