Time Signal System

Time signal system is use where personnel working in hospitals, offices, schools and industries and the likes are notified, by means of alarming a bell or buzzer, about the time for lunch, coffee break, break time, time in and out.

Control Circuit

The control circuit is composed of an automatic time switch (ATS), similar to the one discuss in Article 18.0 and a time delay relay (TR), see figure (A).

To alarm the bell B at 12:00 noon for lunch break, pin 0 is inserted in of slot disk of the ATS at 12. Adjacent to the orange pin o is the white pin W place at 12:15*.

At 12:00 noon, the orange pin 0 will pass the ATS switch. The normally open contact of the ATS (13-14) will close at this time to ring the bell B. Simultaneously with ringing of the bell B, the timer TR (2-7) is energize. The duration of ringing the bell B will depend upon the adjacent in the timer TR. That is , if the TR is adjacent 10 seconds, the bell will ring for 10 seconds.

After 10 seconds the timer contact TR (8-6) will close to energize relay R continuously energized. Contact R (21-22) will open to stop the bell B from ringing. Contact R (11-12) will open to de-energized the timer TR (8-6) will open. Opening contact TR (8-6)will not de-energized contact R since contact R (13-14) is already maintain closed.

The contact ATS (3-4) will remain close until 12:15*. At 12:15 the contact ATS (3-4) will open to de-energized relay R. Contact 11-12,21-22) will close again while contact R (13-14) will open. The circuit condition will brought again to a condition similar to the one shown in figure (A).

The alarming of the bell for 10 seconds can be repeated in 1:00 PM to terminate the lunch break. In this case, another orange pin 0 is inserted at 13:00 and another pin W is inserted at 13:00,at the disk D.

The minimum spacing of an orange pin with a white pin in the slot of the ATS disk will give a 15 minute interval between the closing and the opening of the contact ATS (1-2).