[Woodbob]

Hi,

Thanks.. I have enough room at the Chime for most things. There's an empty outlet
Box, that could be made into a duplex box, that I ran the bell/Xfrmer wires through.

If that didn't work I can easily get to the Xfrm in the basement as well as have an easy
Way to add any wiring I need from the xfrer to to chime box.

[Woodbob]

Hi,

My doorbell sw. is like the one in KISS's pictures, recessed. Plenty of room in the switch for the LED - Resistor and diode.

I would be able to mount the extra diode - Bridge and Relay at the chime works.

[Stratmando]

I don't see why you need anything at the chime, just the parts on my last post, all done at doorbell.

[Woodbob]

Hi,

I'll try getting it working on the bench then look at it again.. You may be right but I seem too be focused on the bench.

[KISS]

Radio Shack has a 5.1 and a 12 V zener diode. If you get about 7V from the bridge, you can put the Zener reverse biased across the relay coil. This would regulate the voltage there, but I don't think you need it.

If 70V gets you 100, the 16 might get you 22. In which case a 24 VDC relay would work.

Based on this design guide:

http://www.hammondmfg.com/pdf/5c007.pdf

A 12-15 volt relay should work. If you'd like, put a 12 V zenier revered biased across the relay and a normal diode reversed biased across the relay.

Then your resistor should be Rtotal = (14.4-2.1)/20mA

Total R should be: (Rtotal) - (Relay Coil Resistance)

[Woodbob]

Hi,

Thanks again... I'm looking

[Woodbob]

Hi,

Follow up:

I have the complete circuit and chime on bench with the Chime and LED working.

I used a 33K 1/2 watt resistor in series with the 20MA LED.

I have 16V at the Bridge when the button is open and 15v when pushed.

I have 2.6V across the LED.

I will let this run and advise.

I'm thinking that if this works out OK, I'll mount everything on a PC board and mount this to the Single gang box that's directly behind the chime, with the parts facing into the box not outward. I can drill a hole on the top and bottom of the PC board to screw the PC board to the box and drill a larger hole for the wires to run through.

Thanks again, will let you know.

[KISS]

Why not mount the PC board on standoffs on the cover of the single gang box, board facing in?

You may be able to bring wires out the cover with grommets and the wires tied with an Underwriter's Knot.

PS:
Why was the sudden interest in lighted buttons?

[Woodbob]

Hi,

That's an idea.

When I bought this house 4 years ago they had a wireless chime that was hard to hear through the house. An inexpensive one at that.

He also cut the pushbutton wires off at the button. He did leave the button wire and the xfrmr wire sticking out of the wall behine the wireless chime.

I added the single gang box for the wires but kept the old chime.

I was doing some electrical work for a friend and replaced her chime, w/o a lighted button and all worked fine.

I liked the sound of her door chime and bought one for myself but I alway's liked a lighted button and here we are.

All still working on the bench, let you know.

[Woodbob]

Hi,

Get your computer hard drive fixed?

I set up a dual boot Win.XP 64 Bit with Win.XP 32 bit.

Been thinking of adding another boot, Windows 7-- 64 bit too fool with...

[Stratmando]

The bridge should be 0 when shorted with the pushbutton.

[Woodbob]

Hi,

The really resistance is in series with the bridge with the button pushed.

Thanks

[Woodbob]

Sorry - Relay

[KISS]

Strat:

Lay off the alcohol. The bridge is the power supply, basically because a 16 VAC relay is hard to come by. There is no way 0 Volts will activate a relay. Without a cap and probably not measuring the voltage with a true RMS meter, all sorts of odd voltages result. There is also no regulation.

A varistor on the mains or the 16V would enhance the design.

[Woodbob]

Hi,

I was trying to be kind..

[KISS]

Strat knows better than that.

The circuit is weird enough as it is. It's easy to make the circuit complicated and it's hard to simplify.

[Woodbob]

Hi,

Yes you're correct, the circuit is working, no need for a filter system etc.

Thanks

[Stratmando]

You are Missunderstanding, When the doorbell is pushes, there is ZERO volts across door button, that is where I woud have the Bridge.It WILL go to zero if wired like my post dated( Jul 18, 2009, 05:23 PM), maybe in your designs?
I wouldn't worry about regulating or filtering.
I wasn't thinking about a relay.


Only the Led, resistor, and full wave brige rectifier at door button, Nothing added at the chime box, no extra wires, no added relays.
What is the final drawing that works?

[KISS]

Here are a few interesting thread


http://www.thathomesite.com/forums/l...2921211.html?2

Here is some info from Zeneth's website. Stupid answere, essentially.

DESA Customer Care Center

This link, probably the one I trust the most:

http://www.nutone.com/PDF/InstallGui...64ins86527.pdf

Suggests that the diode is there so that the chime receives power at all times. It looks like they are suggesting that a lighted pushbutton (assume incadesent) can be used as long as the diode is still used. Why the 40% reduction in brightness, I don't know.

Strat:

Now I see what you're trying to do. Power the light via a bridge. The problem, I think, is it depends on what the "load" of the doorbell looks like.

So, I might agree, that the diode allows the chime to have power all the time. The chime detects the change from pullsating AC to AC and activates the chime. The LED/resistor combination, just doesn't give enough power to the chime. An incadescent light just never allows the chime to see the difference between pulsating AC and AC.

Based on that inferred information a diode in series with an incadescent lamp may work because the pulaing AC to AC would be detected. The chimes internal resistance would determine the brightness of the lamp.

The drawback would be the incadescent lamp burns out.

The design does satisfy:
1. No new wires
2. long life of lamp. LED just gets dimmer over time
3. Small size: LED/Resisor/relay/bridge
4. Three additional parts can be used to increase reliability.
... a) coil back emf supression (diode)
... b) Coil voltage clamping (12 V zenier). You'd have to hold the button till your finger got tired to cause issues.
... c) ZNR clamp on mains or transformer. Not a bad idea to protect the chime and the LED.

SO, I'm going to hypoteisize that the diode allows the chime to be powered at all times and front doorbell presses are detected by looking for a change from pulsating AC to AC.

The back doorbel doesn't require it because that oncepowered, it can be detected conventionally.

The doorbell switch across an incadescent lamp and a diode will work with a reduction in brightness of the lamp. A lihted doorbel would have to be modified to work this way. Nutone claims theirs will work with a lighted doorbell with reduced brightness.

Now the conventional system with the diode across the button and a bridge across that like I think Strat is suggesting, may indeed work, but with more parts in the button. 5 single diodes, resisor and an LED. 4 of the diodes could be replaced by a bridge. The design might have merit. Eliminating relays would be a good thing. Interesting?

I HATE IT WHENMANUFACTURER'S DON'T PROVIDE EQULIVELENT CIRCUITS OF WHAT THE WORLD SEES TO THEIR DEVICES.

[Woodbob]

Hi,

If you recall, my problem began by setting the chime up just the way Zenith suggested.

The wired chime did NOT come with a push button so I bought a Lighted one.

The set up - lighted incadescent button and diode worked fine for about 7 hours then everything went dead. I had to shut off my circuit breaker to the transformer to get it working again.

So, either my eyes and ears are wrong or Zenith isn't correct.

The setup with the LED has been on the bench overnight, some 24 hours and all is working.

Too bad Zenith didn't bother answering my Email about this, perhaps it could have helped THEM.

Here's the working circuit.

I'll be picking up the P.C. board tonight and put it together.

Thanks