Have you ever unintentionally abandoned your front entryway slightly open and had a pet or your small child departure? Here is a shrewd explanation to this situation. This circuit cautions you each ten seconds that your entryway is open.
The circuit is dependent upon the notorious 4-stage ripple-carry binary counter IC CD4060 and a few discrete parts. The counter raised around IC CD4060 developments by one on the negative transition of every clock beat. It's reset (which indicates the sum total of its yields go flat) by applying an elevated beat at its reset info bind 12 through switch S1 free of ticker. An ordinarily-shut (N/C) prod-to-off switch S1 is utilized as the entryway sensor.
Working of the circuit is basic. When the entryway is shut, switch S1 opens according to the mechanical plan and reset bind 12 goes elevated. The oscillator circuit raised around resistor R2 and capacitor C2 quits swaying. Piezo buzzer PZ1 doesn't sound as yields Q7 and Q13 remain flat.
When the entryway is opened, switch S1 closes and reset bind 12 goes flat. The oscillator begins swaying and after a short defer of something like 10 seconds, the piezo buzzer (PZ1) begins giving 10-second extended beeps each 10 seconds. The beep span of the bell might be differed by altering the qualities of timing segments C2 or R2.
Collect the circuit on a general-reason PCB and encase in a plastic bureau. Mount the bureau on the entryway edge and entryway switch S1 close to the handle bolt such that when the entryway is shut the switch (S1) opens. For controlling the circuit, utilize a fitting 3V electric storage device pack.
