"ding" circuit

Ummm... instead of insulting us here in the caff, why not come right out and admit that it is in fact you?

You had jolly well better assume that, or you won't get many replies at all.

Sounds easy enough to me. Just make a circuit with a dinger in it, innit?

On a sunny day (28 Jan 2007 06:16:52 GMT) it happened jasen wrote in :

Good idea, unfortunately I no longer have a Vinyl player .... There are other ways, glueing a small magnet against the cup, and a pickup coil (I have one of those from a telephone recording device).

Once I did a series of sound recordings for an announcement system for some company. We did it late at night, with an electret mike specially bought for it, in an empty office with all computers off, and had some girl make late hours speaking in the text. Oscilloscope to get 100% usage of the 8 bits wide we had. Came out very very good.

If you want to get all fancy about it, yes. ;-)

Best regards, Spehro Pefhany

LOL. I think that would be worth doing. 'Shave and a haircut', anybody?

Best regards, Spehro Pefhany

:o)

I used that for one of my silly projects (cheap mp3) and it's great !

But just in case you want to explore, there's allways Zildjian Cymbal maybe a small crash one or a big ride one.

;o)

With an oxygen-free plunger, for better fidelity. :-)

Ed

These work pretty well...

John

I liked to play with a yamaha FM syntesizer when I was young. It would generate tones by FM modulating one sine wave by another. One could set the frequency ratio (from a fixed list) and the index. I suppose the index could vary with the duration of the tone. It was also possible to use the output as mosulation. That gave rise to chaotic, noisy sounds.

I wonder if the modulator could be wobbled in frequency or just in amplitude.

This mechanism is very well suited to generate bell and gong tones. It doesn't work for vocal-like sounds - for that a filter based synth is better.

Thomas

It has to alert the user, and not disturb a sleeper, so I'd go for a 'bong' note, something in the 200 Hz octave. Around 1 kHz the psychoacoustic effect gets strong (is that a baby crying?), and the fifth harmonic doesn't want to get that effect.

Pink noise gated (like, three pulses) is nearly perfect in the sense of being heard by a nearby (alert) person and blending into the background of city noises for a sleeper. But, what do I know? I grew up with a multiplicity of siblings, I sleep through most things. A cricket, or a dripping faucet, though, will dissolve my slumber.

And you probably get a free "ding" in the bargain.

robert

Maybe you could use a tuning fork? The "E" fork for tuning a guitar sounds Ok to me!

You could hit it with a small rubber hammer driven by a solenoid every 5 seconds or so or be clever and build an oscillator around it.

On a sunny day (Sun, 28 Jan 2007 13:34:48 -0800) it happened John Larkin wrote in :

I have one like that, but I would not call it a 'soft' sound, it makes you jump.

On a sunny day (28 Jan 2007 15:46:14 -0800) it happened "whit3rd" wrote in : It has to alert the user, and not disturb a sleeper, so I'd go for a

The best solution is to tie an electric wire to you toe, and pulse a few kV.

This little circuit

See notes for doing away with the "dong" sound.

ROFLOL.

That'll wake me up, I can skip the coffee step.

Thanks Ross. They use a 74hc14 Schmitt inverter as a 2kHz tone oscillator (33k and 10nF), and feed this to a BJT, which switches a 10k resistor powered from a 10uF cap, creating a decaying square wave. This goes to a low-pass filter and speaker amplifier.

greeting cards..

Maybe get two and slip one into the drywall in the Boss's office ;-)

Come to think of it, I have a PIR-triggered audio playback device kicking around here somewhere.

Best regards, Spehro Pefhany

On a sunny day (Mon, 29 Jan 2007 09:13:34 -0500) it happened Spehro Pefhany wrote in :

PIR triggered has its uses. So I took a PIR alarm, the type that switches a mains relay, added a mains plug and a mains connector, so I have a PIR controllled portable AC outlet. You can plug in a light, a radio, an alarm horn, anything low power that works on an AC adapter, and of course explosives ;-) About 4 meter wire on it, very simple to use (it is a little box with a stand), and it has a timer pot you can set from about 1 second to several minutes.