Starting the Project

In 2006 I started looking at the circuit that we use to control the signals at the SCRR. I first drew the schematic of the circuit and then I got a CAD program from a circuit board company (PCB123) that allowed a person to draw a circuit board on a PC. I had a steep learning curve as I had only made circuit boards by the old manual tape and photo layout methods. The idea was to make a printed circuit board (PCB) of the wiring to make it more reliable and to add features to the existing circuit. The handmade perforated phenolic boards used by my predecessors had some inherent problems. One flaw was that the wiring was made in 3D as it had to crossover other connections and this created shorts from time to time. Another problem was the cold solder joints that occasionally cropped up. Broken wires were another plague. The usual failure was the digital comparator chip so early on this was socketed. The transistors and the LEDs were not. The LEDs were glued to the LB cover in holes and the wiring was tacked to the leads of the LEDs then the other end was soldered to the main logic board outputs.

My first attempt at designing a replacement was to duplicate the wiring on the PCB and make it sightly smaller so it would fit easier into the LB (Light Box) that we use for the semaphore heads. I wound up drawing about 34 versions of the board as I adjusted measurements and locations of various components and got newer versions of the CAD software. I added components and removed them as time went by and Richard Krueger and I talked about the needed components and features.

Then I took a break from making the PCB for the signal control circuit and made a PCB to modularize the LEDs and standardize the spacing of the LEDs in our signals. This was a quick job and it made assembling the signal heads easier and more reliable.

Not much later I lost my house and moved to Tennessee. I looked at the CAD stuff from time to time but just did not have much interest in it anymore. Then it became necessary to move back to Wisconsin so we came back to Hudson and I reconnected with the SCRR.

After the one year hiatus, I got back on the Signal Crew and I mentioned that I still had the CAD software and the circuit board layouts. Rich suggested I work on it again and gave me his suggestions for changes and improvements. I realized that the circuitry was so spread out that it made the board so large that we had trouble fitting it into the LB. I had worked in medical electronics for about 12 years and repaired and adjusted digital and analog circuitry that was assembled on circuit boards that were very closely packed as real estate was at a premium in manufactured products. I looked at the parameters of the circuitry and realized that we could reduce the size of some of the components from what was being used presently. I then did a circuit analysis and worked out what each part of the circuit was doing and I have to admit that I admire the designer (Erik Tromberg) of the original circuit. The circuit is simple and yet well suited to our needs.