Is it possible to make a Sine generator for a couple of quid DIY? I want to
produce a sine wave around 15khz to drive a piezo tweeter...

The well-known 8038 IC function generator. Dunno how much it costs
these days, if it's still being made.

It also has sawtooth and square wave outputs.

I played with one a lot as a kid, that my Dad had made when I was very
young, from an RS kit (PCB included, etc.). Great fun, and educational,
with a 'scope.

But may I ask why you need a sine wave? Esp. at 15kHz and
driving a piezo tweeter?


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie

On Fri, 1 Sep 2006 19:24:33 +0100, "Doki" wrote:

Is it possible to make a Sine generator for a couple of quid DIY? I want to
produce a sine wave around 15khz to drive a piezo tweeter...


Just download a freebie signal generator from the Internet and use
your sound card.

d

--
Pearce Consulting
http://www.pearce.uk.com

"Fleetie" wrote in message
...
The well-known 8038 IC function generator. Dunno how much it costs
these days, if it's still being made.

It also has sawtooth and square wave outputs.

I played with one a lot as a kid, that my Dad had made when I was very
young, from an RS kit (PCB included, etc.). Great fun, and educational,
with a 'scope.

But may I ask why you need a sine wave? Esp. at 15kHz and
driving a piezo tweeter?

Because I imagine it would sound better after playing with a PC based signal
generator. No real reason backed up by actual knowledge or anything that
clever . I just want to **** off kids congregating on some land of mine
and it strikes me that one of these up a tree running off a lithium battery
would do the job and be difficult to shut up.

"Doki" wrote in message ...
Because I imagine it would sound better after playing with a PC based signal generator. No real reason backed up by actual
knowledge or anything that clever . I just want to **** off kids congregating on some land of mine and it strikes me that one
of these up a tree running off a lithium battery would do the job and be difficult to shut up.

As I kind of suspected.

Then you don't need a sine wave, and in fact a square wave might be
better for your purpose, because it's rich in harmonics - though
admittedly, if the fundamental is at 15kHz, the 2nd harmonic will
be way above what even they can hear.

But a square wave is MUCH easier to generate - and cheaper.

You want a 555 timer (another IC, and the first IC I ever played with
(and blew up) as a young kid of 10!). You can definitely still get them.

BTW, I'd be surprised if it had the effect you're seeking. You need a
_serious_ piezo tweeter and some decent power for it to really become
uncomfortable. I guess you've been reading about those "Mosquito" (IIRC?)
devices deployed recently by shopkeepers. You probably want a horn-coupled
tweeter. FWIW, I tried exactly this as a teenager, and was disappointed,
but admittedly, I didn't try that hard. 15kHz is indeed probably about the
right frequency though.

Good luck, anyway.


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie

"Doki" wrote in message
...
Is it possible to make a Sine generator for a couple of quid DIY? I want
to produce a sine wave around 15khz to drive a piezo tweeter...

**Just use a 555 timer to generate an HF (square wave) waveform. Don't
forget: The 2nd harmonic of 10kHz is 20kHz and outside the hearing abilities
of most humans. No need to worry about a sine wave. A 15kHz square wave will
sound just like a 15kHz sine wave. Well, almost.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

"Doki"

I just want to **** off kids congregating on some land of mine and it
strikes me that one of these up a tree running off a lithium battery would
do the job and be difficult to shut up.


** Local councils here have found that playing recordings by Barry Manilow
and Bing Crosby have a repellent effect on gatherings of young tearaways ...


http://news.bbc.co.uk/1/hi/world/asi...ic/5047610.stm




....... Phil

"Phil Allison" wrote in message
...

"Doki"

I just want to **** off kids congregating on some land of mine and it
strikes me that one of these up a tree running off a lithium battery
would do the job and be difficult to shut up.


** Local councils here have found that playing recordings by Barry Manilow
and Bing Crosby have a repellent effect on gatherings of young tearaways
...


http://news.bbc.co.uk/1/hi/world/asi...ic/5047610.stm




...... Phil

Especially through Quad ESL63s

"Fleetie" wrote in message
...
"Doki" wrote in message
...
Because I imagine it would sound better after playing with a PC based
signal generator. No real reason backed up by actual knowledge or
anything that clever . I just want to **** off kids congregating on
some land of mine and it strikes me that one of these up a tree running
off a lithium battery would do the job and be difficult to shut up.

As I kind of suspected.

Then you don't need a sine wave, and in fact a square wave might be
better for your purpose, because it's rich in harmonics - though
admittedly, if the fundamental is at 15kHz, the 2nd harmonic will
be way above what even they can hear.

But a square wave is MUCH easier to generate - and cheaper.

You want a 555 timer (another IC, and the first IC I ever played with
(and blew up) as a young kid of 10!). You can definitely still get them.

Ah. Nice and easy then.

BTW, I'd be surprised if it had the effect you're seeking. You need a
_serious_ piezo tweeter and some decent power for it to really become
uncomfortable. I guess you've been reading about those "Mosquito" (IIRC?)
devices deployed recently by shopkeepers. You probably want a horn-coupled
tweeter. FWIW, I tried exactly this as a teenager, and was disappointed,
but admittedly, I didn't try that hard. 15kHz is indeed probably about the
right frequency though.

Worth a go. It needn't be particularly loud to be unpleasant - those battery
powered cat botherers aren't that loud but are unpleasant if you can hear
them.

"Trevor Wilson" wrote in message
.. .

"Doki" wrote in message
...
Is it possible to make a Sine generator for a couple of quid DIY? I want
to produce a sine wave around 15khz to drive a piezo tweeter...

**Just use a 555 timer to generate an HF (square wave) waveform. Don't
forget: The 2nd harmonic of 10kHz is 20kHz and outside the hearing
abilities of most humans. No need to worry about a sine wave. A 15kHz
square wave will sound just like a 15kHz sine wave. Well, almost.

I've got no clue about harmonics. What does that mean in practice?