[KISS]

Here is one such modification:

LED DIY Doorbell Modification

My button was much smaller. It was one of those recessed into the wall. Only about 5/8" round.

[Woodbob]

Hi,

Looking at your pictures I do not see the diode, only the two LED's and the resistor.

I know you said put the Resistor,LED and Diode in series, how are two LED's wired into the circuit?

The LED or LED's are used in place of the original bulb?

Please draw a schematic with one, then two, LED's, if possible.

Thank you, sorry to be a pain!

[Woodbob]

Hi,

Picked up the parts today.. Only thing, I found the LED's are FW Current: 70ma

and FW supply 2.6 Typical and 3.3V max.. These are 4 pin LED's

I'm thinking I might have gotten the wrong LED's?

Will these LED's change the resistance value of the resistor form 1K?

Thank you

[KISS]

What Radio Shack Part number did you get for the LED's?

Did yoy get this? 20mA 4-pin 130° Power LED (White) - RadioShack.com

Of course Radios Shack info isn't there and probably each pair of the pins is connected to Anode(+) or cathode(-). The cathode side of the diode is the side with the band.

So it's something like this:

*---- 1K ******- LED +*****-diode+*******

LED's are a diode, so they rectify. The added diode is protection when operating the LED off AC.

If you were going to use two, you could add an LED in series or make another string like the above, but put it backwards in the circuit. Then you have one led powering from each side of the AC line.

You should also be able to put the LED's back to back in the circuit too if using two.

At this point, all I wanted you to do do, was to get a feel and to see if it could work. We don't know what the input circuit looks like in the bell chime. It's not a coil of wire, so lighted doorbells have a poor chance of working.

Aside:
If you got a 24 VAC relay and wired the doorbell, lighted or other wise, such that when you pushed the button, the relay coil closed you have what it takes to make a lighted doorbell work.

Now, you take the normally open contacts of the relay and put it where the pushbutton was. ---> instant lighted doorbel.

[Woodbob]

Hi,

Put the parts together on the bench today with an extra Xfrmer and both LED's
Are working together.

Will put the test package onto the push button and test soon, will advise

Thank you.

[Woodbob]

Hi,

Posted my last before I read yours.. No I didn't get the Radio Shack white ones
Mine are red and FW 70MA..

Is this too much of a draw?

Thanks

[KISS]

Your limiting the brightness by the resistor. The spec for most led's is about 10 mA to about 50 mA with a design goal of about 20 mA. The lower the current, the longer lifetime. The higher the current, the brighter and shorter lifetime.

Kind of an oops, but you can use 16V for the volatage. I think I usd 24 without thinking. The LED's only see a half cycle anyway.

Remember, you don't have to cram everything in. Just externally connect your series combination thingy to the button and see if it works.

You may decide on both; LED button and the relay modification.

[Woodbob]

Hi,

I just tried both LEDs one for each side of the AC cycle on my test xformer.

I will try the basic (One LED) for real when my wife wakes up from her nap.

I don't want to ring the bell with her asleep!!

Would this type of setup work with a push button for a garage door opener?

I've tried a lighted push button for my garage but it ony worked for a short while
Then had trouble getting it to work. Had to hold and reset the push button.

After cutting out the push button bulb everything worked again.

I haven't checked the voltage for the garage door - don't know if AC or DC?

Thanks

[KISS]

Measure the voltage across the switch contacts and dermine if it is AC or DC?

If you have a current range on your meter, use something like the 300 mA scale and put the meter in series with the button and measure the current.

Open circuit voltage and short circuit current will give us something to go on.

Otherwise, we have to do the relay trick.

[Woodbob]

Hi,

Just tested the actual door bell but sadly N.G. with 1K in place, wouldn't complete 8 note chime.

Had to reduced the resistance to 10 ohms and now operating OK..

Will let this run for awhile and recheck. When I tried this with just a diode and the regular bulb in place this worked for a few hours then all went out including the chimes.

I believe the 24VAC relay trick would require 4 wires to the push button, correct?

If so mine only has two and would be a mess to rewire. I'm not sure if the wire is stapled
Anywhere in the walls.

Let you know

Thanks

[KISS]

Something seems fishy. You are attaching that resistor/diode/LED network across a switch that doesn't have a bulb in it, correct? I think you put the combination in series with the button. It's supposed to be across the button.

Therefore, the light/resistor/diode gets shorted out when you push the button.

This doesn't work like a normal circuit.
With a bell, which will act like a piece of wire, a bulb and a transformer as long as the light load is small, then the bell can't ring, but the light will light. When the switch shorts out the light, there is enough current o make the bell ring.

You can try reversing the network across the switch too.

You can measure the open circuit voltage and short circuit current as well.

The relay trick should not require anymore than 2 wires to the bell.

[KISS]

Something seems fishy. You are attaching that resistor/diode/LED network across a switch that doesn't have a bulb in it, correct? I think you put the combination in series with the button. It's supposed to be across the button.

Therefore, the light/resistor/diode gets shorted out when you push the button.

This doesn't work like a normal circuit.
With a bell, which will act like a piece of wire, a bulb and a transformer as long as the light load is small, then the bell can't ring, but the light will light. When the switch shorts out the light, there is enough current o make the bell ring.

You can try reversing the network across the switch too.

You can measure the open circuit voltage and short circuit current as well.

The relay trick should not require anymore than 2 wires to the bell.

[Woodbob]

Hi,

Checked again, the switch is wired correctly.
The LED - Resistor 10 Ohm - and Diode in series across the push button leads.
All works now.

If I increase the Ohms by even 10 ohms the chime only plays a few notes - doesn't complete.. The original bulb is OUT of the switch circuit completely.

Could there be a problem using the 70ma LED?

Radio shack #276-0020

Thanks

[KISS]

My computer is crippled right now, recently had a hard drive crash and not up to speed yet. I'll try to scribble something and scan it because I still think we are on different pages, even based on your last post.

[Woodbob]

Hi,

Good luck on your computer.

[Stratmando]

Measure the voltage with the diode in place, then use this calculator:
LED calculator for single LEDs

[KISS]

Munch on this for a while. I didn't pretty print anything. See if it makes any sense.

[Woodbob]

Hi,

Thanks, I'm LOOKING!!

[Woodbob]

Hi,

Here's a simple drawing of my start and how it is now. I used the 70MA LED and a 10 Ohm resister with the diode. It has been working for 10 Hours. The LED is bright - may be too much voltage given the lower resistor.

While looking at your drawing I'm not sure I understand it. Most likely me? Could you explain the new relay and xfrm more. Not sure where it all ties in to my set up hense my drawing.

Thank you

[Woodbob]

Hi,

I didn't draw or pay attention of the polarity while drawing the pictures.