The CIRCUITRON TD-1 is designed to connect to the output of any CIRCUITRON Detection Circuit (the DT-4 is the usual choice) and will provide a variable delay period (adjustable from 0 to over 1 minute) which can be used to control accessories, to provide automatic train stops, etc. The output of the TD-1 is a single pole, double throw relay with 5 amp contacts. These contacts are adequate for controlling locomotives in any scale, and they can be used to either “make” a circuit connection for the time duration, or to “break” a circuit connection for the time duration. The TD-1 requires an 11-15 volt DC power source for proper operation. Although the power source does not need to be regulated, a filtered power source is preferred, and under no conditions should the input voltage exceed 15 volts. Since the accessory terminals of most power packs have outputs in the 16-18 volt range (or more!), they are not a good choice for powering the TD-1 (see POWER SUPPLIES section). The Trigger Terminals on the TD-1 require a momentary or continuous connection to ground [-] to initiate the timing sequence. This connection can be supplied by most CIRCUITRON Detection Circuit outputs, reed switches, track contacts, pushbuttons, etc. Once the timing sequence has been started, further inputs to the Trigger Terminals will be ignored. The TD-1 is constructed on a 2” x 3” printed circuit board.
