I have a device which makes a "ping" noise on a piezo tweeter (one of those 10p sized things you get in wrist watches). Is there any way I can connect this output to some LEDs to flash when it makes the noise?

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Why do people point to their wrist when asking for the time, but don't point to their crotch when asking where the bathroom is?

"Peter Hucker" wrote ...
I have a device which makes a "ping" noise on a piezo tweeter
(one of those 10p sized things you get in wrist watches).

Is this (unidentified) "device" something with some power to it?
Or is it something like a wris****ch that runs on a coin cell
for a year?

Is there
any way I can connect this output to some LEDs to flash

Depends on how much power is available (unknown) and
how much power "some LEDs" take (also unknown).

when it makes the noise?

If you want to drive BOTH the piezo AND the LEDs, then
you need even more power.

Why do people point to their wrist when asking for the time,
but don't point to their crotch when asking where the bathroom
is?

Who do people post silly questions to Usenet?

On Fri, 27 Mar 2009 03:14:01 -0000, Richard Crowley wrote:

"Peter Hucker" wrote ...
I have a device which makes a "ping" noise on a piezo tweeter
(one of those 10p sized things you get in wrist watches).

Is this (unidentified) "device" something with some power to it?
Or is it something like a wris****ch that runs on a coin cell
for a year?

It's got 5 volts into it at half an amp. It's a car satnav. If more power is needed, I can always get 12V from the car, but it would be neater not to.

Is there
any way I can connect this output to some LEDs to flash

Depends on how much power is available (unknown) and
how much power "some LEDs" take (also unknown).

As many LEDs as I can use (well not more than 10).

when it makes the noise?

If you want to drive BOTH the piezo AND the LEDs, then
you need even more power.

I can do without the piezo if I have to. I didn't think the piezo used anything like what LEDs used, so I assumed there would have to be extra power put in anyway.

Why do people point to their wrist when asking for the time,
but don't point to their crotch when asking where the bathroom
is?

Who do people post silly questions to Usenet?

I do.

Or did you mean "why"? In which case the answer is "it's a random joke tag".

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

If you think people aren't creative, watch them try to re-fold a roadmap.

"Peter Hucker" wrote...
Richard Crowley wrote:
"Peter Hucker" wrote ...
I have a device which makes a "ping" noise on a piezo tweeter
(one of those 10p sized things you get in wrist watches).

Is this (unidentified) "device" something with some power to it?
Or is it something like a wris****ch that runs on a coin cell
for a year?

It's got 5 volts into it at half an amp. It's a car satnav. If more
power is needed, I can always get 12V from the car, but it would
be neater not to.

Then you may be able to get away with something as simple
as tapping the signal that drives the piezo and using it to drive
a transistor which switches current to the LEDs. Depending
on how long the sound is vs. how long you want the LEDs
to flash, you may need to add an RC time constant to
"stretch" the length of the flash.

Peter Hucker wrote:
I have a device which makes a "ping" noise on a piezo tweeter (one of those 10p sized things you get in wrist watches). Is there any way I can connect this output to some LEDs to flash when it makes the noise?

A pair of LEDs in series with one of the piezo wires might work.
Eg:
LED1 Piezo
O----+-|-+--|o|----O
'-|-'
LED2

If it's a piezo with its own oscillator, something like this might work:


LED1 + -
O------|----|o|----O
Piezo

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

hi, i have a schematic , that connects up to a knock sensor from a car
engine , ( same thing inside the knock sensor , peizo ?) and flashes a led
when it detects knock..
mark k




"Peter Hucker" wrote in message newsp.uqz2tixhmk2j66@i7...
I have a device which makes a "ping" noise on a piezo tweeter (one of those
10p sized things you get in wrist watches). Is there any way I can connect
this output to some LEDs to flash when it makes the noise?

--
http://www.petersparrots.com http://www.insanevideoclips.com
http://www.petersphotos.com

Why do people point to their wrist when asking for the time, but don't
point to their crotch when asking where the bathroom is?