Switch Machine position feedback

Post date: Nov 18, 2011 7:44:59 AM

You may have seen me working on this board during the Fair.  It's contains 100 Voltage Divider circuits to drop the +24 Volts DC which actuates the mainline switch machines to a voltage below 5 volts which is safe to feed into the C/MRI system and thereby the computer. The computer needs to know how the turnouts are thrown to be able to properly set the signals. 

Unfortunately I had to build this board one and a half times. It turned out even though several tests were made before construction, half of the resistors were not a low enough resistance and we were getting erratic sensing.  Shown here is rebuilding the board.

Robert was also a big help.  He tirelessly cross-connected the existing turnout terminals with a new block of terminals for the above board.