Overview of block controller
Rev. January 1998
Computer
Block controller requires multiple 8 bit parallell ports for full controll.
However you only need one printer port for testing of one block.
Test setup
Connect pin 2-9 to D/A (Digital to Analog) converter and connect Card Select
to pin 1.
Full Setup
One 8 bit buss are used for speed control and one 8 bit buss are used
for selection correct card. This two busses will support up to 254 blocks.
In adition one or more 8 bit busses are used for input. one parallell port
for every eight block. In adition one port is used for overload protection.
Digital to Analog Converter
This is implemented with
IC1 - 74374
and multiple resistors
r1 .. rn
Overload Detector
This is implemented with a transistor that get power when the voltage over
rm becomes more than 0.7 V. When that happens a signal is sent to the AD converter
and the AD converter output goes to approx 4 Volt. this will give an output of
maximum 500 mA. My prototype cards are can cope with this for at least a minute.
diode dx are used to generate i feedback signal to the computer. Further
plans include a circuit for turning of power to block controller after a few
seconds if computer does not solve the problem.
DCC
There is a DCC input that can be used for controlling a Decoder engine, or
a conventional engine from a conventional powerpack.
Relay block
Rel1. Selects input from DA converter or DCC
Rel2. Is direction controll for DA converter
train Detector
A bridge rectifier are used to generate a signal of 1.4 volt when there are
engines in the block. Optocoupler ic2 and r1 sends a signal to computer whenever
train detector senses something on the track.
Building instructions
Block Controller Cards currently exists with two different configurations
One controller card with support for one block:
BLCK1R6 - Block Controller 1 rev 6
and one controller card with support for four:
BLCK4R6 - Block Controller 1 rev 6
Functionally they are equivalent, but blck4r6 requires fewer wires to install,
and are therefore bether if you have many blocks.
Software for block controller
Users guide for block controller
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