One Doorbell Button with 4 Doorbells/Chimes

[1BadBoy]

Does anyone have any suggestions for being able to have our front door's doorbell button operate 4 doorbells within the home (one in garage, one in shop and 2 in our 3 story home)? Maybe a particular brand that may allow this setup?

I was hoping there was some way to do this maybe with a higher voltage/wattage transformer (e.g. 16v/30watt), but I'm still not sure if this is enough power. If not, is it at all possible to use multiple transformers to power 4 doorbells connected to a single doorbell button (e.g. maybe with 1 doorbell button connected to 2 transformers where each transformer would be connected to 2 doorbells)?

It seems to me that much larger homes must have similar needs, and I'm wondering how they are addressed. Thanks in advance for all insight and suggestions!

[Nestor]

There are wireless doorbells available now, and that would save you the trouble of running wires through your house. My understanding is that wireless doorbells are battery operated, and that would also address your concern about power requirements as each door bell would have it's own power source.

But, just for the record, transformers CAN be connected in PARALLEL to provide additional power for door bells, zone valves and any other such low voltage AC equipment. Generally you can't do that if the transformers are of different impedance because the different impedance will result in one transformer's magnetic field developing slightly earlier or later than the other's, and that will result in a voltage difference between the transformers which will cause one transformer to drive a current through the secondary windings of another transformer. But, if you have multiple IDENTICAL transformers, you can connect them in parallel to double, triple or quadruple the power output from a single transformer. That's because if they're all identical and connected in parallel, then each one's magnetic field will develop at the same time from the applied AC voltage, so the voltage at all the secondary coils will be identical at any given time, and therefore there won't be any voltage difference between transformers to cause any current in any other transformer's secondary coil.

Heath Zenith | Wireless Battery Operated Door Chime Kit With White Cover | Home Depot Canada

Google Heath Zenith to find their web site and check to see if they sell additional chimes for this kit so that you can have multiple chimes sounding in different areas of your house if your door bell is pressed. I'd be surprised if they didn't as that would be the natural extension of a single battery operated wireless door chime.

Also, at least one company (Dimango) makes an "Extend-a-chime" door bell kit. This one requires that you connect a transmitter to the low voltage wiring of your existing chime. The transmitter then sends out a signal that causes all the other Extend-a-chime door bells in your house to sound.

http://www.homehardware.ca/en/rec/index.htm/Plumbing-Electrical/Electrical/Chimes/Doors/Plug-ins/Plug-In-Extend-A-Chime-for-Existing-Doorbell/_/N-ntjx1/R-I3613799

http://www.dimango.com/da-extend-a-chime.htm

That'll be 35 cents. Please contact the forum moderator to arrange for payment.

[1BadBoy]

Thanks, Nestor, that's at least $0.35 worth !

I'll tell you that I've had a wireless chime before, and wasn't very pleased with it. For instance, unless you pressed the button and held for about a 1/2 second or so, the bell would not recognize the press and would remain silent. We just got used to holding the button for a short time. And the batteries seem to run down more often that seemed reasonable. I'm guessing that the wireless technology for these items has greatly improved in the last several years, so my concerns may have less weight today then they did several years ago. However, given my past experience, and since the house is all open to the studs, it's very easy to run the low voltage wire for wired doorbells. And I'm home-running all the wires back to my mechanical room so I'll have one place to make all connections. The setup seems very straight forward. Except for powering 4 doorbells from one doorbell button. I've spoken to a couple of manufacturers who tell me that their max is 3 chimes (I'm not sure if I would do doorbell chimes or bells at this point). But with only 3, I would have to exclude either my shop or my garage. And I'm not sure I would be able to hear the doorbell from either location, which is why I'm interested in 4 doorbells to ensure adequate coverage. When you mention wiring in "parallel", I'm not sure how that works. I'm not afraid of wiring, and if I had a diagram, I'm sure I could easily handle the task.

Thanks for your response to my question!

1BadBoy

One last question. I'm using 18/5 (thermostat wire) to every doorbell button and doorbell location. If I end up running more than one transformer in parallel, is 18/5 wire adequate for the power (amps) that would be travelling the wires or should I step up to 16 guage? I'm thinking I'm okay, but wanted a second opinion. Definitely don't want any overheated wires to accomplish my task of 4 (or potentially 5) doorbells.

[HayZee518]

door bell

I don't know how complicated you want to go, but let me get this straight. you want to wire multiple chime units to ring when one button is pressed from one location or multiple button locations to emit a different sound at multiple location. [ front door - one sound, back door - a different sound]
Nestor is correct in stating you can parallel transformers only if the impedance is the same.
look on your chime units and see what the current draw is -or- look for the watts and divide by the applied voltage to get amps. 18-2 is good for about ten amps, but your chime units are just a momentary [made] electromagnet.

[1BadBoy]

I don't know how complicated you want to go, but let me get this straight. you want to wire multiple chime units to ring when one button is pressed from one location or multiple button locations to emit a different sound at multiple location. [ front door - one sound, back door - a different sound]
Nestor is correct in stating you can parallel transformers only if the impedance is the same.
look on your chime units and see what the current draw is -or- look for the watts and divide by the applied voltage to get amps. 18-2 is good for about ten amps, but your chime units are just a momentary [made] electromagnet.

Yes, I will have all wires home-run back to my mechanical room. In there I'll place the transformer(s) and I'll do all the connections. I don't think it's too complicated really, but realized there are more considerations than I had originally thought.

I will have a back door and a front door, but for simplicity sake, I am just asking about a single doorbell button at our front door that when pushed will cause all 4 units to tone (chime).

From the sounds of it, I just need to put the wires in place (18 guage sounds like it's more than sufficient, correct?) and then purchase the bell/chime units. Once I do that, I can determine the wattage/ampacity needed and see if I can find a single transformer that can do the job, or find two transformers that can be connected in "parallel".

When connecting transformers in parallel, is the va (watts) cumulative? In other words, if I have two transformers rated at 10va each, does that equal 20va? Or is it just more capable of maintaining 10va under load?

I'm thinking it's got to be like a flashlight with multiple batteries, but I haven't gotten a good parallel in my mind. This is more my brother's forte .

[HayZee518]

doorbell

since you'll run all home runs back to your mechanical room, use 18/3 doorbell or thermostat wire. there should be inside a white, red and green or blue. now for the transformer. instead of wiring multiple units go and buy a "buck-boost" transformer with a 120/240 primary and a 16/32 volt secondary. you'll be using the 120 volt primary and the 16 volt secondary. rating: you can get 5va 10va, 20va, 50va. please go do an inquiry in your browser for a bust/boost transformer. there should be a chart of sizes. home depot or lowes may have them, but an electrical supply house will definitely have them. check back and I'll make a diagram for you.

[Nestor]

A low voltage transformer will have two leads and two screw connections. The two 120 VAC wires will typically be black and white. The screw terminals will be the low voltage side of the transformer.

To wire two or more transformers in parallel, you'd simply collect all the black wires together and connect them to the brass screw of a 120 volt polarized plug. You also connect all the white wires from the transformers together and connect them to the nickle plated screw of a 120 volt polarized plug. Then you insert that plug in any 120 volt duplex receptacle, and you have multiple low voltage transformers all producing low voltage AC power in synch with each other.

Then, one would run a wire connecting all the top screw terminals on the low voltage side of all the transformers, and another wire connecting all the lower screw terminals on the low voltage side of all transformers. Those two wires would then be run to all of the door chimes that are powered by that bank of transformers. And, of course, the door chimes would all be connected in parallel so that if one chime doesn't work, it doesn't knock out the entire string of door chimes.

Two 40 VA transformers wired in parallel will deliver 80 VA. So, if each chime requires 30 VA, you have enough power to run 2 chimes and 2/3rds enough power for a third chime. If you want 4 chimes, you'll need three identical 40 VA transformers wired in parallel.

[1BadBoy]

Thanks, guys - you've given me some great ideas on how to move forward. And, more importantly, that how I'm wiring will work fine for my application. I'll be sure to add a couple of more outlet boxes to the wall in my mechanical room to which I can attach transformers later if needed.

[HayZee518]

doorbell wiring

Nestor must have multiple transformers on his mind when you can do the same with one buck-boost transformer. see my accompaning diagram. it shows ONE transformer connected to five loads through two pushbuttons - a front and a rear.
if you still wish multiple transformers, follow Nestor's diagram for parallel wiring. just make sure the transformers you buy are identical with regard to impedance rating.

[1BadBoy]

Nestor must have multiple transformers on his mind when you can do the same with one buck-boost transformer. see my accompaning diagram. it shows ONE transformer connected to five loads through two pushbuttons - a front and a rear.
if you still wish multiple transformers, follow Nestor's diagram for parallel wiring. just make sure the transformers you buy are identical with regard to impedance rating.

You're correct - your diagram is clear. I just need to identify which buck-booster transformer I would need to use once I have my doorbells picked out. Either way, I have more than one way to skin that cat.

Question though on Nestor's diagram:
> The transformers are not really connected together other than to use a common wire back to the doorbell button which would complete the circuit for each transformer (separately). Are these really in parallel? Maybe I'm missing something here because I don't think it will require identical transformers, would it?

Thanks for the great diagrams guys!

Edit: I re-read Nestor's description and understand that they are in fact in "parallel" (low voltage side). I apologize for my lack of understanding at first read. Thanks again guys, really appreciate all the guidance!

[HayZee518]

doorbell

ok, a transformer is a coil. matter of fact two coils wound right on top of the other. they are wound around an iron core. the coils have resistance, but because of an iron core they now also have impedance. impedance is the opposition to flow at a given frequency. in this case 60 Hertz or 60 cycles. Loudspeakers have a coil around a magnet which is iron or ceramic or incalloy. speakers have impedance also, like resistance, measured in ohms. if the impedance isn't perfectly balanced then the resulting total impedance presents a load on the line which may in time overheat and draw excessive current. eventually it will burn out. a buck-boost eliminates this problem. it too has impedance but it is not in parallel with any other device. another thing, in a transformer there is a 180 degree phase shift from the input voltage. for a parallel connection like nestor stated, the input winding must be wound in the same direction as all the others and there's no way to tell if they are - the secondaries of all the other transformers may be 180 degrees out of synch with each other.

[Nestor]

I've never heard of a "buck boost" transformer so I can hardly recommend that Bad Boy use one. I know multiple identical transformers wired in parallel will work, so that's what I was suggesting. If one "buck boost" transformer will replace several lower power transformers, that'd be the way to go. I just don't want to tell the guy to use something that I've never used and have no experience with.

[1BadBoy]

ok, a transformer is a coil. matter of fact two coils wound right on top of the other. they are wound around an iron core. the coils have resistance, but because of an iron core they now also have impedance. impedance is the opposition to flow at a given frequency. in this case 60 Hertz or 60 cycles. Loudspeakers have a coil around a magnet which is iron or ceramic or incalloy. speakers have impedance also, like resistance, measured in ohms. if the impedance isn't perfectly balanced then the resulting total impedance presents a load on the line which may in time overheat and draw excessive current. eventually it will burn out. a buck-boost eliminates this problem. it too has impedance but it is not in parallel with any other device. another thing, in a transformer there is a 180 degree phase shift from the input voltage. for a parallel connection like nestor stated, the input winding must be wound in the same direction as all the others and there's no way to tell if they are - the secondaries of all the other transformers may be 180 degrees out of synch with each other.

Electronics is not my forte, but I think I grasp what you are saying:

If I installed transformers that didn't match (e.g. different output, manufacturers, models, etc.), that could cause problems between the disparate transformers potentially causing them to overheat (with the potential for fire too) and/or wear out prematurely.

However, if I installed identical transformers (e.g. same output, manufacturer, model, etc.), the transformers theoretically should be in sync. And in that scenario, they should work without the potential for the issues stated above, correct?

I understand about manufacturing tolerances to know that the transformers will never *exactly* match, but they should be so close as to not cause the issues described with unmatched transformers - at least I *think* that would be the case.

Am I correct in this thinking?

[1BadBoy]

I've never heard of a "buck boost" transformer so I can hardly recommend that Bad Boy use one. I know multiple identical transformers wired in parallel will work, so that's what I was suggesting. If one "buck boost" transformer will replace several lower power transformers, that'd be the way to go. I just don't want to tell the guy to use something that I've never used and have no experience with.

Hi Nestor. I've never heard of a "Buck-Boost" transformer either. And Google hasn't helped much at this point. I've found a lot of information regarding Buck Boost transformers, but nothing in regards to using one for a doorbell.

HayZee518: in all fairness to Nestor, I believe he was just answering my question about how one connects transformers in parallel. With that said, I'm definitely interested in learning more about using a Buck Boost transformer for my doorbell system if it will allow me to use a single transformer. Do you have any more information or specific Buck Boost transformers that could be used in my scenario? Based on the va requirements of one doorbell I saw at Home Depot, it was rated as 10va I believe. If I had 4 of those, I'm guessing I'd need a 40va Buck Boost transformer. How can I locate one of these?

[HayZee518]

buck-boost

typically a buck-boost transformer is used to increase or decrease line voltage by electrically adding or subtracting voltage from the applied voltage. say if you had a 208 circuit that you had to run at 240 volts absolutely, then a buck-boost would be wired into the circuit to provide that extra 32 volts.
Jefferson Electric has buck-boost transformers available online, and I'm sure electrical suppliers have them too!
Nestor - do your homework - go find a buck-boost and read about it.
I've used a buck-boost setup where I had a three phase soda can crusher from Germany and needed to reduce the line voltage of 240 to 208. Two such transformers were needed.
If you look on their chart, a .050kva transformer will satisfy the 50 va requirement. KVA means Kilo Volt Amperes or One thousand volt amps. if you move the decimal point three places to the right, you'll get 50va. its just like dividing by one thousand.