Powerflash with existing doorbell.

[Clever1]

I like the fact that our doorbell system allowed for a lighted push button. I want to keep this feature but I also want to use a powerflash module to trigger an X10 chime device in several other areas of my house as we are unable to hear the regular doorbell. In the future I would also like to be able to trigger a camera and IR functions to display the camera on our TVs. Can I use the powerflash to do this and still keep the power for the lighted switch?? If not other options or ideas??

[sbessel]

I do beleive that the Elk-930 would do what you need.

I have mine connected to my Ocelot and I am unable to get it lit without a huge effort, so I traded it for one that had no light, now I don't feel bad.

[rocco]

The PowerFlash will work if you wire it parallel to the lighted push-button. Like the light bulb, it will see voltage (whatever your doorbell transformer is, probably 12v AC) when the button is not pushed. It will see no voltage while the button is pushed.

The INPUT switch should be set to A (volts) and the MODE switch set to 3. When the doorbell is pushed, a House/Unit OFF command will be issued by the PowerFlash. When the doorbell is released a House/Unit ON command will be issued.

Make sure your doorbell is not 24 volts, as the PowerFlash is only rated to 18 volts.

[Rupp]

Rocco,
Can you draw a picture? I too miss my light although the porch light now turns on automatically it would still be nice to have it back. I am so electronically challenged that parallel and series makes little since to me. When I think parallel I think of parallel parking which I believe looks more like series in electronics

[rocco]

Sure, Rupp. Here's a picture.

You're right, once you are parked, you are in series. But as you pull up beside the car you are going to park behind, the two cars are in parallel.

[Rupp]

Hum ...
A couple more questions if I may. Can the connection be made between the transformer and the dorrbell as well?

Can 12 vAC shock you?

[Rick Tinker]

12VDC can shock you yes - if there is enough current provided. The telephone system is a great example of this. Although driven by 48V batteries at the central office, the connections between the batteries are the size of your wrist because of the current that flows in the system! I can touch and connect telephone wires all day, but if the phone rings while I am doing it, then the person who called me is instantly an enemy because I can guarantee I felt it! (Ringing voltage is different than normal voltage, and the system already has a lot of current available to it.)

Anyway, most doorbells do not use hardly any current, so I would not worry about it. What you need to be aware of if you work on it live is shorting out power and ground and causing your transformer to fry.

[sbessel]

I do beleive that most newer doorbells use 16vac... But in reality most transformers put out much higher than what they are rated for, I would guess in the 20-24vac range prior to being loaded down with the ringer on button press... I am not sure the rating of the powerflash....

On a side note: Telephone ring voltage is 90vac at 20hz, hence the shock, the 20hz is what gives the ring to the bell...

[Clever1]

Ok so if the doorbell system is 24VDC and the powerflash is rated at 18VDC I would need something in series to the powerflash in order to drop that voltage down into the right range.

[Rupp]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> ...the 20hz is what gives the ring to the bell...

This message has been edited. Last edited by: sbessel, Fri, 16 July 2004 11:11 AM

Thanks,

Scott
<HR></BLOCKQUOTE>

I thought it was the metal leg beating against the bell?

[Microchip]

Rick.
I think you are a little off track with saying "its the amount of current available".
How much of a shock you get depends on the resistance the body sets up between either the ground and the live wire or between the live and the other side of the supply if the supply is not grounded. This resistance varies from person to person. Obviously there are many calculations involved.
I have seen a person handle live wires 240VAC without any problems and he could hold onto an exposed car ignition lead. Other experiments were carried out but I will not get into that.
Yes 12 VAC may shock you, its about 18V peak. I have also seen 12VDC shock somebody, but only when they make the first contact or break the contact, this is probably due to some inductance somewhere.
I DONOT RECOMMEND ANYBODY TO TRY ANY TESTS TO FIND OUT HOW RESISTIVE THEIR BODY IS!

[huggy591]

If the doorbell transformer is 24VAC, get a relay with a 24VAC rated continuous duty coil, wire the coil in parallel with the bell unit, and hook the powerflash up to the relay contacts - use the contact mode on the powerflash. Just have to have the relay coil require more current to energize than the light bulb draws in the pushbutton, and you should be ok. Simple, cheap, clean.

Or set up a motion detector instead and you'll know when people come up to the door, whether or not they ring the doorbell.

[sbessel]

... or (like suggested above) get the elk unit, cheap and easy and actually does other things!

[kschorz]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Rupp:


I thought it was the metal leg beating against the bell? <HR></BLOCKQUOTE>

Well...I do know if I pound a metal hammer against my head my ears will ring. I just verified it.
Does this count?

[rocco]

Here is a clearer version of the picture above. If the voltage is greater than 18 volts, you could use a relay as Gordon suggested, or you could put a zener diode in series with the PowerFlash to subtract some voltage.

But I think Scott's ELK-930 idea will be the most reliable, as it will isolate the PowerFlash from the doorbell, and has no mechanical components.