User manual

GBM-8 English
Page 27
§ After placing the parts, please double check for correct polarity.
Check the PCB tracks for solder bridges and short circuits created
by accident. This would cause faulty operation or, in the worst
case, damage. You can remove excess solder by putting a clean
soldering tip on the spot. The solder will become liquid again and
flow from the soldering spot to the soldering tip.
4. Operation overview
The track busy indicator GBM-8 can be used in analogue (d.c. or a.c.)
layouts as well as in digital layouts. The module can supervise a
maximum of eight track sections.
The GBM-8 is internally divided into four sections with two track busy
indicators each, which can be connected to a maximum of four different
booster or transformer sections.
Detecting vehicles
With a sensivity of 5 mA the GBM-8 detects reliably locomotives and
carriages with lighting, but not vehicles not consuming current of their
own.
Hint: As a rule, the small current flowing after painting a carriage´s axle
with resistive lacquer is not high enough to be detected by the GBM-8.
For this application the fourfold track busy indicator GBM-1** can be
used.
Electric consumers located in a switched off track section can be
detected by the GBM-8 when an additional resistor is mounted in
parallel to the switch.
Due to technical principles, with (analogue) d.c. layouts the GBM-8 can
only detect vehicles driving into the supervised track sections in a
particular direction. In case the detection of vehicles from both
directions is required, the track busy indicator GBM-1** can be used.