Diodes – Velleman DCA75 User Manual
Page 8
Atlas DCA Pro User Guide
December 2012 – Rev 1
Page 8
Diode junction
Green-K Blue-A
VF=0.694V at 5.00mA
Diodes
The
DCA Pro will analyse almost any type of diode. Any
pair of the three test clips can be connected to the diode, any way
round. If the unit detects a single diode, a message similar to the following
will be displayed:
In this example, the Cathode (symbol of
K) is connected to the Green test clip
and the Anode (symbol of A) is
connected to the Blue test clip,
additionally, the Red test clip is unconnected.
The forward voltage drop is also displayed; this gives an indication of the
diode technology. In this example, it is likely that the diode is a standard
silicon diode. A germanium or Schottky diode may yield a forward voltage of
about 0.25V. The current at which the diode was tested is also displayed. The
DCA Pro typically tests diodes (PN junctions) at a forward current of 5mA.
Note that the DCA Pro will detect only one diode even if two diodes
are connected in series when the third test clip is not connected to the
junction between the diodes. The forward voltage drop displayed
however will be the voltage across the whole series combination.
The DCA Pro will determine that the diode(s) under test is an LED if
the measured forward voltage drop exceeds 1.50V. Please refer to the
section on LED analysis for more information.