We are building period correct Reading block signals using dual color common cathode ultrabright LEDs. Our previous signals were controlled using cuts in the outside rail. From there we used track voltage through a rectifier to trip DC relays. We are now going to have more signals and want to make a standard control board. The LEDs only draw 30ma at 5vdc. We will still be using the cut outside rail for control of the blocks.
Our concern is messing up the DC signal. In the past like I said we used track power converted to dc. I've also use a small dc power supply and controlled it via the outside rail. We are even open to using a logic circuit instead of relays. AC relays are an option but are less available and generally more expensive than dc coil relays. We don't want to use infrared or optical detection because of reliability. So I'm looking for feedback on known working systems that won't degrade the DCS signal. Also we use the block signals for actual operation, not just to look good. It's a large layout with long tunnels, blind curves, and multiple trains on the same mainline.
Thanks much,
Dave North Schuylkill High Railers
Original Post
C:US:3160
They are opto-isolated and each have an indicator LED on-board. For less than $2 a relay, you get a complete board ready to use!