Timer Circuit for Front Door Bell

[erickendall]

Hello everyone. My first time here. I don't know much about electronics and I was hoping for a little advice regarding this latest project that I have going at the moment.
I recently bought a ten inch brass bell and want to use it for the front door bell for the house. I have it mounted inside and It's close to a 240vac 50hz power input. There is also a two core tps cable running through the wall to the outside for a press button.
Here is what I am proposing to do. I want to wire in a solenoid close to the bell. Probably this one:
https://www.electro-tech-online.com/custompdfs/2010/12/series43.pdf
and set up a mechanical "donger" off it and have it actuated by the push button (N.O.) on the outside. I'll probably use this one:
**broken link removed**
All pretty straight forward so far, but what I was hoping to do was to have the bell "gong" twice just with the one press of the door bell. Maybe with a half second delay between gongs. Actually it would be good if this time duration could be adjustable. I was hoping to keep things fairly simple without the need to step down for 555 circuitry.
Does anyone have any suggestions on how to go about this possibly through the use of relays and caps?
Thanks again

 

[Reloadron]

Before all else I would rethink the solenoid. Do you really want a 220 volt solenoid? Typically you would want low voltage throughout the entire system. I would start with a low voltage system like maybe 24 VDC or even 12 VDC. Then maybe configure a 555 or 556 to get a few pulses when the button is pushed and let the 555/556 drive a MOSFET that fires the solenoid. Something along those lines. Even though you want to avoid the use of 555 timer chip(s) I don't think it is wise to run 220 VAC to a door bell on the exterior of your home.

Just My Take
Ron

 

[erickendall]

Thanks for the feedback Ron. You are probably correct with your suggestion regarding the supply voltage.It might be asking for trouble.
Looks like the 555 may well be the way to go. If this is the case, I might engage the use of a standard 12v dc starter motor solenoid from an automobile. These are pretty high on current I would imagine. Any help with circuitry would be most appreciated.
regards,
Eric

 

[4pyros]

I would stay with a standard door bell system. The ding/dong is done mechanically no electronics. Have you looked at how a standard door bell works? You should be able to use a solenoid from a standard door bell for your bell. Andy

 

[Reloadron]

OK, before I guess any further personally if I wanted to replace the doorbell I would likely just run over to Lowes or Home Depot and buy something that I liked. Simply because it is easier than building one.

Most of today's doorbells are electronic as was pointed out. Mine plays the Marine Corps Hymn.

Now if you want to pursue this I would run with an off the shelf solenoid similar to those that can be found here with a 12 volt DC coil and you actually want a PUSH type. Automotive solenoids are pull type and draw considerable current as well as large and bulky. Additionally I think it would be a mechanical nightmare to use one.

For a timer you want something along the lines of a dual one shot or two stage one shot maybe similar to the attached image taken from an old Radio Shack Engineers Notebook by Forrest M. Mims III. This circuit could likely be modified to give you the pulses out. I would use a pair of MOSFETs to drive the solenoid. The unidentified pin for the second output should be pin 9 on the 556 dual timer chip.

Ron

 

[KMoffett]

With a low voltage DC solenoid, to can have a bong or a bong-bong. The first circuit will pulse a spring-return solenoid once when you press the button (SW) and once when you release it. The second one will pulse the solenoid once when you press the button, but not when you release it. The value for the capacitor will have to be determined experimentally by the DC supply voltage and the solenoid's coil resistance.

Ken

OOPS! Corrected schematics!

 

[Reloadron]

Maybe I am missing something but Ken, in the first circuit on the left it looks like the +12 V is going to ground through RY1 N/C contacts?

Ron

 

[KMoffett]

You are right! Too quick a mod of an existing schematic. I'll go back and correct it. Thanks!

Ken

 

[4pyros]

Why do you need electronics?

I would stay with a standard door bell system. The ding/dong is done mechanically

Andy

 

[audioguru]

I had my home enlarged and found that the original Edwards American doorbell was not loud enough to be heard in the far room.
At Home Depot they still sold the same old American one plus a much less expensive Chinese one.

The American one has just two tubes that vibrate. It is not loud. The Chinese one has the same two tubes plus two acoustical Helmholtz chambers that also resonate and make the ding dong much louder like DING DONG!.

 

[erickendall]

Thanks for all the feedback guys. I guess one other problem with using the low voltage switching circuitry is that if it's mains driven, there will always be current drawn from the primary unless it's battery powered. Thanks for that circuit Ron. I think I'd be able to adapt either a push or pull solenoid for the mechanism, but yes you are right about the current and mounting. I want to make this unit to have some visual look about it. Depending what I end up with regarding the solenoid, I want to either cast up or fabricate a bell crank arrangement that will strike the bell. This will be polished brass to match the bell and will be highly visible.
Andy: I'm not really familiar with what's on the market regarding those type of door bells, but I would imagine them to be battery powered and fairly light on. this 10 inch bell will take a bit of force to make a good "gong", or is that "dong"!!!
Thanks for those schematics Ken. I understand the first one with the 2 gongs, but why the need for R1, C1 and D1? I would have thought just the relay actuating the solenoid directly would be adequate.

 

[KMoffett]

My wife has hearing problems, and could not hear the door bell when she was in the basement or upstairs. I bought three wireless bell/receivers and two buttons (front and back doors) at Home Depot. Because they are dip switch coded each switch can now activate all three bells. Bing-bong=front...Bing=back. The receivers take 4 C-cells each, that don't last long. So, I when to GOODWILL and bought some 5VDC/2A wall warts and dummied them in place of the batteries. Three X $1.99...and I never have to change them again.

Ken

 

[4pyros]

Andy: I'm not really familiar with what's on the market regarding those type of door bells, but I would imagine them to be battery powered and fairly light on. this 10 inch bell will take a bit of force to make a good "gong", or is that "dong"!!!

The mains powered ones are still avalible.

Google "doorbell chime"

Andy

 

[erickendall]

Thanks Andy, but I couldn't really find anything appropriate. I'm in Australia. That may be why. I would imagine the mains powered units would consume current 24 / 7.
OK, so here is a real challenge to anyone up to it. Let's say that I want to power this unit from the mains, but not have continual current being drawn through the primary of the step down. Could I use the press button switch to switch and latch the 240v and then have the two pulses through the 555 or 556 circuitry. This circuitry would then need to unlatch the 240vac supply. Any thoughts on this?

 

[4pyros]

I would imagine the mains powered units would consume current 24 / 7.

Yes but vary little if thare is no load.

Could I use the press button switch to switch and latch the 240v

Safety is the concern. You would need a safe outside switch to switch mains power and at that point you mite as well switch the primary of a step down transformer.

Andy

 

[erickendall]

OK, so this could be another alternative. Let's say we use some small battery power just for the push button and actuation of the 240vac step down transformer and associated timer circuitry. Any thoughts on this method?

 

[4pyros]

That would work but would the cost of the batterys outweigh the savings of not using a vary small amount of mains voltage 24-7? Andy

 

[erickendall]

The power costs here are on the rise and are predicted to double in the next few years. Any suggestions on circuitry?

 

[audioguru]

Why don't you understand that a half-decent power transformer draws almost no power when it has no load?
It will be loaded only when the pushbutton is pressed.

 

[4pyros]

The power costs here are on the rise and are predicted to double in the next few years. Any suggestions on circuitry?

Read This;

An energy saving doorbell | OliNo


But when you are talking about $2 or $3 dollors a year to run a doorbell transformer it will take years before it pays for its self.

Andy