tams elektronik FCS Series Manual page 18

English
Diodes
Diodes allow the current to pass through in one direction
only (forward direction), simultaneously the voltage is
reduced by 0,3 to 0,8 V. Exceeding of the limit voltage
always will destroy the diode, and allow current to flow in
the reverse direction. The diode type is printed on the
package.
Diodes must be mounted in a given direction. The negative end is
marked with a ring.
Light emitting diodes (LEDs)
When operated in the forward direction the LEDs light.
They are available in several different versions (differing in
colour, size, form, luminosity, maximum current, voltage
limits).
The cathode (-) has to be connected to the neagtive
voltage. With wired LEDs the longer wire is the anode (+).
With SMD versions the cathode (-) is marked (bevelled
edge, colour marking or similar).
Light emitting diodes should always be connected via a series resistor
which limits the current and prevents failure. With circuits designed for
the connection of LEDs the series resistors are often integrated on the
circuit board.
Page 18
FCS modules