--- /dev/null
+v 20121123 2
+C 40000 40000 0 0 0 title-B.sym
+C 47700 44600 1 90 0 zener-1.sym
+{
+T 47100 45000 5 10 0 0 90 0 1
+device=ZENER_DIODE
+T 47200 44900 5 10 1 1 90 0 1
+refdes=Z1
+T 47900 44900 5 10 1 1 90 0 1
+value=5.1V
+}
+C 47600 45900 1 90 0 resistor-2.sym
+{
+T 47250 46300 5 10 0 0 90 0 1
+device=RESISTOR
+T 47300 46100 5 10 1 1 90 0 1
+refdes=R1
+T 47900 46100 5 10 1 1 90 0 1
+value=2K7
+}
+N 47500 46800 47500 47000 4
+N 47500 47000 48500 47000 4
+N 47500 44600 47500 44400 4
+N 45500 44400 48500 44400 4
+N 47500 45900 47500 45500 4
+N 47500 45700 45500 45700 4
+C 45500 45800 1 180 0 output-1.sym
+{
+T 45400 45500 5 10 0 0 180 0 1
+device=OUTPUT
+T 44700 45400 5 10 1 1 0 0 1
+pinlabel=Data pin (e.g.D2 on Nano)
+}
+C 45500 44500 1 180 0 output-1.sym
+{
+T 45400 44200 5 10 0 0 180 0 1
+device=OUTPUT
+T 44700 44600 5 10 1 1 0 0 1
+pinlabel=GND
+}
+C 49300 47100 1 180 0 input-1.sym
+{
+T 49300 46800 5 10 0 0 180 0 1
+device=INPUT
+T 48300 46700 5 10 1 1 0 0 1
+pinlabel=Right rail (+18V)
+}
+C 49300 44500 1 180 0 input-1.sym
+{
+T 49300 44200 5 10 0 0 180 0 1
+device=INPUT
+T 48300 44600 5 10 1 1 0 0 1
+pinlabel=Left rail (GND)
+}
+T 48300 45700 9 10 1 0 0 0 1
+To SCX digital track
+T 44700 45000 9 10 1 0 0 0 1
+To Arduino