Manual OC32/NG
VPEB
Control your Miniature World
Page 38 of 48
Version 1.0 – December 15
th
, 2017
2017 Leon van Perlo
together they can be connected in parallel as long as the current does not exceed 500mA.
6.4.4
LED’s antiparallel
OC32 I/O Pin: Resistor-array (preferred) or 500mA Sink Driver
With some signals, the LEDs are connected anti parallel. An
example would be the Märklin "Hobby" signals 74391 and
743xx. It is preferred to drive these signals with the 5V
outputs of the OC32 but the 500mA driver will do the trick
as well.
Using the 5V output configuration (figure 28) the signals
can be connected to 2 consecutive outputs of the OC32.
The required resistor is part of the OC32. For the resistor
array take a value of 100
Ω
.
Should you have some spare 500mA outputs left,
this will work also (figure 29). In that case you need
to add 2 resistors between the 2 outputs and Vp.
Be aware that the signal has to be connected the
other way around because of the inverting operation
of the 500mA driver. The value of the resistors
depends on the required voltage Vp. At 12V a
reasonable value would be 1k5, but one could
experiment.
6.4.5
LED’s on barrier bars
OC32 I/O Pin: Resistor array or 500mA Sink Driver
On Dutch railroad crossings 3 lights are fixed onto the barriers of the railroad crossing
(AHOB). The light at the end (the top light) is lit continuously where the two other lights are
blinking alternately. If you want to construct this in your miniature world it might be a
challenge to attach the wires along the moving barrier. In any case the fewer wires, the
better. Presented is a diagram to drive these 3 LEDs with only 2 wires and 2 outputs of the
OC32. In the case of two barriers the circuit can be connected twice in parallel as long as
the LEDs you use are of the same type and from the same manufacturer (if possible from
the same production series). The (double) diode is put somewhere on the barrier. Take care:
it is a SOT23 diode (SMD), also very tiny. To attach the LEDs to the barrier you will have to
select SMD types also.
Fig 28: Connecting LEDs antiparallel
in 5V mode
Q(x+1)
Q(x)
Q(x+1)
Q(x)
Fig 29: Connecting LEDs antiparallel
in 500mA mode
Vp
Rv
Q(x+1)
Q(x)
Rv
Vp
Rv
Q(x+1)
Q(x)
Rv
Fig 30: LEDs on the
barriers
(5V mode)
Q(x+1)
Q(x)
BAT54C
Top
Q(x+1)
Q(x)
BAT54C
Top
Fig 31: LEDs on the
barriers
(500mA mode)
Q(x)
Q(x+1)
BAT54C / BAV70
Top
Vp
Rv
Rv
Q(x)
Q(x+1)
BAT54C / BAV70
Top
Vp
Rv
Rv
Control your Miniature World
VPEB
Manual OC32/NG
2017 Leon van Perlo
Version 1.0 – December 15
th
, 2017
Page 11 of 48
K1, K2, K3 and K4 are 2,5mm spring loaded connectors.
Accepted wire size = 0,08mm
2
– 0,5mm
2
K5A and K5B are 3,81mm spring loaded connectors.
Accepted wire size = 0,08mm
2
– 1,5mm
2
When inserting thin wire into the K5 connectors (0,20mm
2
or less), pay attention that
the wire is centered and inserted straight in the connector. Otherwise the wire may not
always be grabbed entirely by the spring.
To insert wires in either type of connector:
•
Strip insulation off the end of the wire for about 10mm.
•
In case of stranded wire: twist the strands together.
•
Put the connector on a solid surface with the orange clips facing upwards.
•
Push-in the orange clip of the pole you want to insert the wire in. You can do this with
the tip of your finger or nail, but a small screwdriver or other similar tool may be handy.
•
Gently insert the wire until you feel it touches the end. Use no force.
•
Release the orange clip.
•
Gently pull the wire to check it’s grabbed correctly
If you find it difficult to push in the orange clips without the connector flipping over, you may
want to do that while the connector is inserted in the OC32/NG module. Be sure that the
module is powered off when you do and don’t push too hard, otherwise you may bend the
PCB part of the connector. This risk is specifically there on the upper half of the 10 pole
connectors that go in K5A and K5B.
When inserting the top connector in PCB part K5A or K5B when you have a module without
enclosure, do not push very hard, because in extreme cases you may bend the connector on
the OC32/NG. While inserting, support the back of the connector to relief excessive strain.
If you have the module with enclosure the risk is minimal, since the enclosure provides
mechanical support for these connectors.
