# Changing a continuous electrical signal to a pulse?

874 Views 5 Replies 5 Participants Last post by  ChuckF.
How do I convert a continuous electrical signal to a pulse?

I use a door bell as an entry chime for my retail store. Each time the door is opened is like someone ringing a doorbell (Ding Dong). My problem is that if someone holds the door open for deliveries, the one more thing conversation , or it's just a nice day it is like someone holding down the button on a doorbell causing the electromagnets to overheat and melt the plastic parts in the doorbell. (I have gone through three already.) What I am looking for is a way to convert the continuous stream of electrical current (ding - long wait for door to close - dong) to a pulse of electricity that would reset once the connection is broken. ( ding - dong- door waits to close then doorbell resets.)

I hope I have been clear (and not too redundant), but I don't even know what terms to google that describe the action I'm looking for.

Thank you in advance for any help or bright ideas!
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What you are talking about is a momentary relay. There are a couple of different ways to do it, but I think a better solution is to change how the bell is activated.

Your door bell should be set up so that it only activates when the door is swung open or on closing.

Is there a way you can change the 'button' to do that?
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The bell is activated by a magnetic door sensor. When the door is opened the circuit is closed allowing current to flow to the door chime.
Must be a ready made device to that I hear them all the Tim in stores. Chime one when you open the door
The bell is activated by a magnetic door sensor. When the door is opened the circuit is closed allowing current to flow to the door chime.
Ayuh,.... Like ddawg said, a momentary relay switch will do the job for ya,....

Lotsa choices, ya gotta know the voltage yer dealin' with,....

Just wire it 'tween the door switch, 'n the chime,...

When the door opens, it'll chime once, 'n go off, til the next time the door switch triggers it,....
It won't stop it when some kid is swingin' the door open, close, open, close, open, close, like they do on occasion,.....:wink2:
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Easiest way: use a (normally open) reed switch that is not activated when the door is closed or fully open, but only when the door is opened an inch or so and the magnet on the door sweeps by it. Downside: it will gong once as it opens and again as it closes.

Many doorbells have two inputs, a 'ding-dong' for the front door, and a 'dong' for a back door. See if yours has two.
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