by raceamerica » Thu May 24, 2018 3:43 pm
110VAC or 220VAC is converted to approximately 15VDC inside the tree. The 15VDC is feed to the 2900 or 2910 timer through the 4-conductor interconnect cable. The 15VDC is also converted to lower DC voltages for the circuitry inside the tree. The 2910 converts the 15VDC to lower DC voltages for the circuity inside the timer. The 15VDC is then distributed through all track cables to the track sensors.
When the 15VDC is shorted to one of the sensor signals or even to ground, the voltage will be lower. Also, the farther away from the timer you get with longer downtrack cables, the lower the voltage. the amount of voltage loss in the cables depends on cable distance from the tree and number of sensors connected along the way.
If the 15VDC is shorted to one of the sensor connections in the track cables, bad things could happen to the sensor or the circuitry in the timer. Once again, the farther away from the wire short the sensor or timer is, the better chance no permanent damage will occur.
Same power distribution occurs in the 2700 wireless system, just fewer cables and only 60FT and start sensors connect to the 15VDC.