timer T09 disconnects the doorbell. The doorbell will be
disconnected after two rings and stay disconnected until
the doorbell switch is released.
The closing of NO contacts M01 on rung 005 enables
T02 for seven seconds, giving T02 the time necessary to
produce five pulses.
T02 on rung 028 pulses the buzzer five times when
the door bell is pressed.
T03 on rung 009 is timed to turn on at the third pulse.
T04 on rung 011 is timed to turn on at the fourth
M02 on rung 013 is on if the doorbell is pressed for a
second time on the third ring.
34 December 2015
FIGURE 10. T02 rings the buzzer five times.
FIGURE 8. T09 disconnects the doorbell switch after two
FIGURE 11. Rungs 008 and 009.
FIGURE 12. Rung 011.
FIGURE 13. Rungs 013 and 014.
FIGURE 9. Rungs 004 and 005.