Prevent a door Chime from being activated more than once every 10 secs

Thread Starter

GUlNNESS

Joined Apr 17, 2017
34
Hello Forum users!
This is my first post ... please forgive me if I make mistakes / waffle on / use the wrong terminology / confuse
Three sections - Please feel free to skip ... to GREEN

ITALICS red - Background of my issue
BOLD green - Project - What I would like the circuit to do
BLUE - SUMMARY

Door bell
I purchased a door bell and the battery soon became depleted fairly quickly, so i decided to use a PSU to alleviate the need to replace batteries
The door bell broke - the solenoid locked up and would not move
I bought a new unit and the same thing happened again
I looked into the issue further and discovered that the doorbell push button had been pushed in at a funny angle and stayed "stuck-in"
I surmised that the solenoid had been receiving a constant power source and had burnt out
I was lucky enough to be able to exchange the doorbell unit and used the supplied 9v (PP3) battery
When the door bell stopped working again, due to another sticking button situation, the battery was dead
I oiled the doorbell buttons outer edge and was unable to make it stick again - solved!
I would still like to use the 9v PSU but need to prevent the button, if it sticks again, from frying the solenoid
Hence this post ...


I thought that if i bought a 555 timer i could rig up a circuit that would allow a delay in the button pressses
So far, plenty of people talking about it but no solution ... that I can find

My QUESTION is thus:
What circuit would allow the following to take place?
A guest arrives at the house and presses the door bell button
The door bell rings
If the guest presses the button again, within a preset time of 10 seconds, nothing happens
After 10 seconds have passed, the circuit would allow the door bell to activate
Each time the button is pressed, one of two things happen
1 - The door bell rings and the timer starts again
2 - If the timer is still in the counting state, each button press or continuous depressed state would cause the timer to start again

SUMMARY
I have searched high and low but cannot work this out
I have lots of 555 timers and can obviously get extras parts as and when
My electronic ability is limited and I am not even sure that what I am asking is possible - although I am a fan of "nothing is impossible - EVERYTHING is possible"
Thank you one and all in advance for your help
 

Dodgydave

Joined Jun 22, 2012
11,277
Just let the 555 pulse the door bell, use a simple monostable timer circuit, door push operating the 555, and that fires a relay for say two seconds. Use the circuit on the right...


555mono.gif
 

crutschow

Joined Mar 14, 2008
34,201
.............
A guest arrives at the house and presses the door bell button
The door bell rings
If the guest presses the button again, within a preset time of 10 seconds, nothing happens
After 10 seconds have passed, the circuit would allow the door bell to activate
Each time the button is pressed, one of two things happen
1 - The door bell rings and the timer starts again
2 - If the timer is still in the counting state, each button press or continuous depressed state would cause the timer to start again
I'm confused. :confused:
You were saying you wanted a circuit to ignore a stuck button, but your request is for a circuit that only allows the guest to ring the button no more often then once every 10 seconds.

Don't you just want a circuit that will provide a pulse to the door bell for every button push, which will ignore the button if it stays depressed?
 

Thread Starter

GUlNNESS

Joined Apr 17, 2017
34
In addition to this ...
a) I would like it to be 'at least cost'
b) To avoid solenoid burnout if the doorbell is repeatedly pressed - malicious ringers
 

Thread Starter

GUlNNESS

Joined Apr 17, 2017
34
I'm confused. :confused:
You were saying you wanted a circuit to ignore a stuck button, but your request is for a circuit that only allows the guest to ring the button no more often then once every 10 seconds.

Don't you just want a circuit that will provide a pulse to the door bell for every button push, which will ignore the button if it stays depressed?
Hello Crutschow,
Thanks for the interest ...
I have placed an amendment ... malicious ringers
 

Thread Starter

GUlNNESS

Joined Apr 17, 2017
34

crutschow

Joined Mar 14, 2008
34,201
Wow. That's cheap!
Looks like the one!!!
You will need some way to keep the circuit drain from killing your battery.

Here's a 555 timer that shuts itself off and draws no current after the 10 second holdoff.
It generates no more than one half-second pulse in this 10 second interval before it can be retriggered.
The CD4050 non-inverting buffer provides power to the 555 while it is timing and buffers the half second output pulse generated by R3 and C5.

upload_2017-4-18_1-26-41.png
 

Attachments

Kjeldgaard

Joined Apr 7, 2016
476
If TS can use the following I do not know, but I have for decades had a working doorbell with this circuit:
IMG_8604.JPG
It was originally a continuous ringing bell, with the classic breaking contact in series with the coil.
The operating voltage was initially a 4.5 volt battery, but with experimentation, I found the specified RC component and a 9 Volt block battery gave a sufficiently sound and demanded the button to be released for a few seconds before the bell again could say a single ding.
Since in fact, nothing else than the consumption from the electrolyte capacitor leakage current, so a battery keep power for years.
 

crutschow

Joined Mar 14, 2008
34,201
If TS can use the following I do not know, but I have for decades had a working doorbell with this circuit:
View attachment 124976
It was originally a continuous ringing bell, with the classic breaking contact in series with the coil.
The operating voltage was initially a 4.5 volt battery, but with experimentation, I found the specified RC component and a 9 Volt block battery gave a sufficiently sound and demanded the button to be released for a few seconds before the bell again could say a single ding.
Since in fact, nothing else than the consumption from the electrolyte capacitor leakage current, so a battery keep power for years.
I like that.
It's simple and should solve both of the op's problems.
 

Thread Starter

GUlNNESS

Joined Apr 17, 2017
34
If TS can use the following I do not know, but I have for decades had a working doorbell with this circuit:
View attachment 124976
It was originally a continuous ringing bell, with the classic breaking contact in series with the coil.
The operating voltage was initially a 4.5 volt battery, but with experimentation, I found the specified RC component and a 9 Volt block battery gave a sufficiently sound and demanded the button to be released for a few seconds before the bell again could say a single ding.
Since in fact, nothing else than the consumption from the electrolyte capacitor leakage current, so a battery keep power for years.
Hello Kjeldgaard
I am not great at deciphering circuits ...
although it may look simple ... i am struggling
Are you able to do a breadboard layout for me at all please?
 

Thread Starter

GUlNNESS

Joined Apr 17, 2017
34
AMENDMENT
So far, thank you everyone for your help
May I rephrase my project:

Doorbel button (Simple open/close)
Ding Dong unit - Powered via a 9v DC PSU
Timer circuit (e.g. 5 seconds)
If the timer is not running and the button is pressed the door bell rings and the timer begins
If the timer is running the bell does not ring
Each press of the button restarts the timer

I thinks that's it
:)
 

Thread Starter

GUlNNESS

Joined Apr 17, 2017
34
It consists of a resistor and a capacitor.
The solenoid is the doorbell solenoid.
The lines are wires and the dots are wire connections.
What are you having a problem with?
Hello
Please see the attached breadboard layout
LHS and RHS
Both turn on the LED (in lieu of the solenoid)
Press the button - the LED lights up ... Release the button the LED turns off
There is not a delay ... What am i missing?
 

Attachments

crutschow

Joined Mar 14, 2008
34,201
Please see the attached breadboard layout
LHS and RHS
Both turn on the LED (in lieu of the solenoid)
Press the button - the LED lights up ... Release the button the LED turns off
There is not a delay ... What am i missing?
I'm missing component values and schematics for the two circuits so how can I tell what they are doing?
(I don't read circuits from breadboard layouts and my psychic abilities are sadly lacking in that area. :rolleyes:)
(And why are there two circuits?)

The circuit is designed to provide a pulse to a solenoid, not light an LED.
The LED lights with the small current going through the resistor, but that small current won't keep the solenoid energized.

It's not designed to provide a delay when you push the button.
Why do you think it would and why would you want a delay?
 
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