Now that I have teased you all with the signals. I am going to run a thread on building them.
I had always wanted a fully functional ABS on my railroad. The cost of commercial signals and the electronics for driving them, has always been a factor for not doing it. So, I decided to design and build my own. I have a degree in electronics design, which I have used to build many model railroad electronics devices. From throttles all the way to this. Also, understand...some of this is experiment as I go.
Anyway, the parameters for the system was for it to be either fully interlocking (ABS) or CTC (distant operation). What I finally decided upon, was for it to be fully ABS, which can be interfaced with a computer if one so desires.
I realize that some, maybe a lot of you, don't know electronics. That's not meant to be an insult.
I will try to keep the 'geek' factor down. There are however, some things I have to explain that may get a little complicated. I will try to answer any questions that may come up in the process.
This system is three color: Green single head...absolute, proceed at normal speed.
Yellow single head...absolute, proceed at half speed. Be prepared to stop at next signal if red.
Red single head...absolute, stop!
Green, lower yellow, two head signal ( sidings or route changes) absolute, proceed at slow speed.
Green, green...(rail crossings) two head signal absolute, proceed at normal speed.
Green, yellow...(rail crossings) two head signal absolute, proceed at normal speed.
Yellow, yellow...(rail crossings) two head signal absolute, proceed at half speed.
Yellow, Red...(rail crossings) two head signal absolute, stop
Red, red...(rail crossings) two head signal absolute, stop
I think this covers all the indications. You can see the pics above for the signals physical appearance. Not sure all this is even prototypical. But, I am the owner, so it is prototypical for my railroad.
I wanted this system to be very inexpensive. There is only one chip per signal head driver. For turnouts, there are two chips per driver. These chips cost me .40 each. So for two signals per block, that's only .80! The signals them selves cost me about $2.00 per. That includes the LED's. Those cost .07 apiece through a company named LED Switch. www.led-switch.com
The PCB's cost me about $1.00 each. I purchase full boards through a company named Circuit Specialists. From these, I make my own circuit boards with my design. They are very reasonable in price. www.circuitspecialists.com
So, that comes to what...$3.61 per signal! I think that is very do-able!
Now that I have introduced what I am getting ready to do with this thread. I will do my best to start the SBS today. I will try not to disappoint.
Right now, duty calls (other than model railroading)...I have to make a run across town. Hopefully, I can get this started today. I am not trying to bump myself to the top of the list or to keep my thread the most obvious.
Dave
Seattle