SD-1 SIGNAL DRIVER, 3 ASPECT, 3 LAMP / LED
The CIRCUITRON SD-1 provides all the logic and output drivers to control any 3 lamp, 3 color Block Signal or multiple lamp Position Light Signal. The three outputs on the SD-1 can each control a maximum of 250 ma. and they will power either LED or incandescent lamp type signals. If your signals use LEDs, make certain that they are connected with a common positive (anode) connection of all LEDs (the signal should have 4 wires, and the “common” connection should go to [+]. Most, but not all, signal manufacturers follow this design. Detection circuits (such as the CIRCUITRON BD-1, BD-2 or BD-3) that provide a logic low (- or ground) output are needed for a minimum of 2 blocks to display all three aspects. The SD-1 is constructed on a 2” x 3” printed circuit board and requires a 10 - 18 volt DC input for proper operation.
 
Although CIRCUITRON Block Occupancy Detectors can directly control 2-color block signals without any additional logic or drivers necessary, whenever you want to connect prototypical 3-color signals, you must have a driver circuit for each signal which will accept the outputs from the “home” and “following” block detectors and translate this information to drive the signal to the proper aspect. CIRCUITRON has driver circuits available for nearly all popular signal types including single and dual head searchlight with Bi-color or Tricolor Light Emitting Diodes, color light signals of any configuration (type D, type G, etc.), position light signals (Pennsylvania, Norfolk & Western, etc.) and color position light signals (B & O). We also have a semaphore driver to be used in conjunction with the CIRCUITRON TORTOISE™ Slow Motion Switch Machine.
 
800-5520 SD-2 SEMAPHORE DRIVER
MSRP $29.95