You must set your browser to accept cookies and to enable Javascript in order to access certain functions of this site.

This is the old HomeTech Solutions website.
Please visit our new website here

How Do I...Connect To a Doorbell

This application note describes how to hook up a Powerflash module to a doorbell. With this setup, when the doorbell rings, the Powerflash module will send PLC codes over the powerline to control devices such as lights and remote chimes.

Doorbells(below)
Connect the Powerflash Module(below)
Testing(below)
Troubleshooting(below)
Uses(below)
Home Automation(below)

Doorbells

Doorbells are typically wired as shown. The main pieces are the transformer, pushbutton, and the ringer.

You can usually find the transformer in an out-of-the-way place where AC power is available, such as the garage or a utility closet. (Electrical codes preclude placing an unprotected transformer in the attic or outdoors.) Most doorbells operate on 12 volts AC so the transformers typically have 120 volt AC inputs and 12 volt AC outputs.

The pushbutton is a normally open switch that keeps the transformer current from flowing to the ringer until pressed. Lighted pushbuttons allow a small amount of current to flow all the time; enough to light the pushbutton, but not enough to activate the ringer.

There are many kinds of ringers. The most common use a solenoid to strike one or two tuned pieces of metal, one when the pushbutton is pressed, and the other when released. In some ringers, a third terminal activates a different solenoid that is mechanically prevented from striking the second piece of metal. Thus it makes a different sound. Just "ding", instead of "ding dong." By wiring this third terminal to a pushbutton at the back door, the different sounds tell the occupant whether it's someone at the front or back door.

Connect the Powerflash Module

First, determine where you're going to put the Powerflashmodule; It's better to plug it into a wall outlet and run two small wires to the ringer than it is to put it by the ringer and run AC to a wall outlet. If you want to put the Powerflash in the attic it should be placed in a metal box. (Consult you local electrical codes.)

Once you've determined where to put the Powerflash module, connect a length of wire to each screw terminal on the Powerflash. The type of wire is not important, use whatever is convenient. The voltages are small and the current is minuscule. Run the two wires to the ringer.

On every doorbell we've encountered, there is a place (at the ringer) where we can get nearly zero volts when the pushbutton is not pressed, and 12 to 24 volts AC when the button is pressed. We can connect the wires from the Powerflash to this place.

Remove the cover from your ringer. If it has just two connections, these are the two that we'll connect to the wires from the Powerflash. If it has three terminals and only two of them have wires connected, use the two with wires. If all three have wires connected, use the terminal marked "transformer," "common," or "power" for one wire and the terminal marked "front" for the other.

Connect the two wires from the Powerflash to the terminals you identified. (It doesn't matter which wire is connected to which terminal.)

Replace the ringer cover. You're ready to test the Powerflash.

Testing

On the Powerflash, set the house code and unit code to the same settings as a light that is visible from the doorbell pushbutton. Then set the "Input" switch to "A" and the "Mode" switch to "3".

Now press the doorbell pushbutton. The light should go on when the pushbutton is pressed and go out when released.

Troubleshooting

If the light doesn't respond, turn the light on manually. (This makes sure the light works and that the local switch is on.) Then ring the doorbell again. The light should go out.

If the light still doesn't respond, try the "test" and "all units off" button on the Powerflash module. If "all units off" turns off the light, but "test" doesn't turn it on, you've selected the wrong unit code on the Powerflash. If neither button has any effect, you may have selected the wrong house code on the Powerflash or you may have a PLC transmission problem (call us for further information).

Uses

Now that you have PLC codes that transmit when the doorbell rings, you can do all sorts of things. Here are a few examples:

Additional doorbell ringers

Set the house code and unit code on a chime module to the same settings as the powerflash module and plug the chime module in anywhere. The chime will ring whenever someone rings the doorbell. Perfect for large houses, basements, garages, anyplace where you'd like to be able to hear the doorbell but can't.

Doorbells for hearing impaired

Dedicate a light as a "visual doorbell" for the hearing impaired. Now they can see when someone rings the doorbell. You can use a lamp module or a wall switch module. Just set the dials on the module to the same settings as the Powerflash. Warning: Dedicate a light for this use only; If you try to use an existing light that is also used for general illumination, when the doorbell rings-- the light will go out!

Doorbell turns on porch light

Have your porch light (or any light) automatically turn on, and stay on, when your doorbell rings. Change the "mode" setting of the Powerflash to "1". Set the house codes of the Powerflash and lamp module to the same letter, but a different letter than any other modules in your home. Set the unit codes on the Powerflash and lamp module to different numbers. Now, when the doorbell rings, the light should go on (responding to the "all lights on" code) and not go back off (because of the different unit numbers).

Home Automation

You may want things to work a little differently than they do with this setup. The Powerflash module is great for getting PLC codes onto the powerline, but it isn't particularly smart.

You may, for instance, want the porch light to come on when the doorbell is pressed. And then go back off after a few minutes.

Or maybe you want some, but not all, inside lights to come on when the doorbell rings, and not go off at all. This is great for returning home late at night.

These limitations of the Powerflash can be easily overcome with a Home Automation Controller such as M�nage Automation's UCIX. With UCIX and the doorbell interface described here, you can do all sorts of things based on the fact that someone rang the doorbell. Here are a few examples:

When you're "away", turn on an inside light a few seconds after the doorbell rings. Burglars often ring the bell to make sure nobody is home before breaking in. (If the house was dark and a light comes on, they vanish, pronto!)

When you're home, mute (or turn down a little) the television or stereo when the doorbell rings.

Or turn on the television (if it isn't already) and display the view from the front door camera for a few seconds! (CCTV video camera available from HomeTech.)

If you don't want guests after a certain time, you could disconnect the original doorbell ringer (leaving the two wires connected to the Powerflash) and use a chime module for the ringer. UCIX could decide whether to ring the chime based on the time of day. It could even turn out the porch light to give a subtle hint to the "unguest."