Hi all,

I wanted to take a 3.5v momentary signal and extend its duration or at least use it as a marker to activate another source of voltage. The single beep is not sufficient on the Chamberlain CWA2000, too easy to miss... So I want to make it louder and longer.

Thanks

 

What is the nature of the triggering signal?

A monostable multivibrator chimes to mind...

 

It seems that this can be accomplished. What is your level of being able to design or build electronic gadgets?

PS, I'm posting the location of a similar thread so the helpers can see that another person accomplished this task.

http://forum.allaboutcircuits.com/showthread.php?t=88877

 

What is the nature of the triggering signal?

A monostable multivibrator chimes to mind...

Could you explain the basic operation of this?

It seems that this can be accomplished. What is your level of being able to design or build electronic gadgets?

PS, I'm posting the location of a similar thread so the helpers can see that another person accomplished this task.

http://forum.allaboutcircuits.com/showthread.php?t=88877

I was already looking at that... but I need it to switch for a period of time. That only seems to operate it as momentary as the bell chimes.
So a timed switch set off by the momentary signal.
I have pretty basic knowledge. I understand the very basics. I do all the wiring on my car, I understand signal wires, switches, 4/5 pin relays, I have built custom led arrays. Though I havent used transistors, capacitors or ICs.

 

A monostable multivibrator is geek speak for, "oscillator". Apparently there is an audio frequency oscillator in the "Alert System" that drives the speaker to sound like a bell chime. You need to tap into that circuit to get some signal that will trigger another device that runs longer when it is activated. You also need to find or make some voltage to run the new sound device.

If you can get the speaker driver to turn a transistor on, that can trigger an LM556 timer. The first section will set the amount of time you want the audio to be on and the second section will make the audio. That particular chip can run a small speaker.

 

As #12 suggested, if you are attempting to make an add-on, you would need to have a device triggered by the standard audio output line (the monostable multivibrator aka one-shot), which would enable an audio oscillator (the 556), which generates the audio signal that the speaker will emit.

If you can get your hands on a schematic of the thing, it may be possible to modify the original circuit to accomplish this...

 

Oh, darn. tshuck caught me making a mistake. Monostable doesn't continue oscillating.

 

Oh, darn. tshuck caught me making a mistake. Monostable doesn't continue oscillating.

I did? I thought you were talking about using half of the 556 for the monostable and the other as the oscillator...

 

A monostable multivibrator is geek speak for, "oscillator".

There's the mistake.

Yes, I was talking about using a 556 for a one-shot and an oscillator, but the first sentence was misleading.