DCC on Ken K's layout
Ken is using NCE switch-its with Circuitron Tortoises. 
We tried using red-green in series with the switch machines, but we
wanted two on the panel.
But the voltage drop ended up being to high. since each r/g LEDs had a
two plus volt drop.
We now feed +/- 12v to the tortoise, on pins 2 and 3, and send pin
4 back to the panel to drive
a pair of r/g LEDs with a 1k resistor.
The Toggle switch is a SPDT monetary center off, we use DPDT for
crossovers.
we cut stock circuit boards down into small pieces, like Radio
Shack 276-150, and mounted the resistor and two LEDs to them, we left
about 1 to 3/4 of an inch on the LEDs so we could bend them to line up
with the holes drilled in the panel. The LEDs are wired so the two long
leads (anode) are connected to each other, so one is always green and
the other red.
- We ran a separate +/-12v power ($25 ea @ 5A) because DCC power is
more expensive ($180 for 8A).
Control panel and wiring for a double slip switch with tortise and nce
switch-its
first some logic tables
Think of a double slip switch has having 4 quadrants:
top left
|
Top Right
|
bottom left
|
bottom right
|
With two DPDT toggle switchs we can control the whole thing.
for a train going from/to bottom left to bottom right I'll represent as
points on left and right are both up, train is clear either way on the
bottom
For a train going from/to
bottom
left to top right would be
points on the left are down, point on right are up
for a line up going from/to top
left to top right would be
points left and right are down
For a line up going from/to top left to bottom right would be
points on the left are up, points on the right are down.
points
right | up
down
left |
---------------------------
up | R
R G R
| G
G R G
down | R G G G
| G
R R R
Notice how the opposite side controls the line up .... tho it seems
weird,
the toggle switch on the left will control the Tortise on the right
which will drive the leds on the left,
and the toggle switch on the right will control the torise on the left
which will drive the leds on the right!