Interesting 16V thought: knock light LED?

[Joe.Doty@lcnetwork.com (Joe Doty)]

I've taken a multimeter that had a "spike" LED (not sure of the voltage
threshold) and hooked it to two of the knock sensor wires. Then I tapped
the knock sensor with a hammer.  On a decent enough hit you could make
the LED come on.

Joe Doty
IT/Development
joe@lcnetwork.com=20

> -----Original Message-----
> From: Julie Macfarlane [mailto:juliemac57@hotmail.com]
> Sent: Friday, March 28, 2003 3:42 AM
> To: tberk@mindspring.com; rhock99@epix.net
> Cc: brianm@earendel.org; scirocco-l@scirocco.org
> Subject: Re: Interesting 16V thought: knock light LED?
>=20
> If the attaching wire was sent to a HiZ (High impedance >10meg ohm)
input
> amp, (a comparitor would be better) the signal drain would be minimal.
The
> output could be sent to pin2 of a 555 timer in monostable mode.
> As a monostable the output would drive the led for X# seconds each
time
> the
> input was triggered. A potentiometer sets the time on for the LED time
the
> input pulse arrives.
>=20
> <$10.00 from Radio Shack for the parts.