delay clicking on a doorbell

Thread Starter

gabby55

Joined Feb 20, 2020
8
hello
i want to build a delay to the switch that connects to my doorbell. the purpose of that is i want that only house members know that if they want to activate the ring bell the will need to press long-press on the button about four seconds so that other people will press shortly the button won't trigger the doorbell.
I was thinking of using a capacitor and connecting it to the switch line whether it would be sufficient or should a transistor also be connected?
 

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Dodgydave

Joined Jun 22, 2012
8,825
A 555 timer will work, or resistors and a capacitor with a transistor relay, the 555 can bbe configured as an on delay, by putting the trigger capacitor to pins 2, 8 and the resistor on pin 2 via the door push switch to pin 1, make the capacitor 100uF and the resistor 3K7 to give you a delay of approx 4 seconds triggering.
 

Audioguru again

Joined Oct 21, 2019
890
My AC operated doorbell goes "ding" when the button is pressed and a solenoid hits the ding sounder then it goes "dong" when the button is released and the solenoid goes back to rest and hits the dong sounder. So a user can make a very quick dingdong or a ding then later a dong.
It would be tricky and complicated to make it wait 4 seconds while the button is pressed then go ding dong when the button is released.

I tried it just now. My doorbell went ding bark, bark, bark for a long time. My dog heard it.
 

crutschow

Joined Mar 14, 2008
24,352
You could rectify the AC to generate a DC supply for a 555 one-shot delay as Dodgydave suggested.
The 555 would drive a small mechanical relay to power the doorbell at the end of the delay.
LTspice simulation of example circuit below:

If it's a ding-dong bell as AGa mentioned, then it will ding at the timeout and dong when the button is released.

1582392968350.png
 
Crutschow, your circuit is brilliant.
At first I thought the output of the 555 would stay high since when the button is released then the trigger is still low but the button powers the 555 so that won't happen.
 

Reloadron

Joined Jan 15, 2015
5,126
That is pretty ingenious.

I replaced mine with a wireless button. Now it plays the Marine Corps Hymn but around holidays I opt for sounds of the season. :)

Ron
 

Thread Starter

gabby55

Joined Feb 20, 2020
8
You could rectify the AC to generate a DC supply for a 555 one-shot delay as Dodgydave suggested.
The 555 would drive a small mechanical relay to power the doorbell at the end of the delay.
LTspice simulation of example circuit below:

If it's a ding-dong bell as AGa mentioned, then it will ding at the timeout and dong when the button is released.

View attachment 199693
Hi,
thanks for the help
But my bell makes a uniform sound
 

crutschow

Joined Mar 14, 2008
24,352
To avoid any possible damaging transient current through the TRIG input from C1 when the voltage collapses at the end of the bell ring, I suggest adding the 10kΩ diode R1 in series with the TRIG input as shown below.

One other interesting characteristic of this circuit is the momentarily releasing and pressing the button after the time-out will cause the bell to go off and back on without any significant delay, as shown.

1582520058806.png
 
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Thread Starter

gabby55

Joined Feb 20, 2020
8
i really appreciate your help, thank you.
Where in the picture (attached), I connect the component?
I have been looking in the online stores component similar to your component, but can't find.
I will appreciate your help with guidance.
 

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