Interesting 16V thought: knock light LED?

[tberk@mindspring.com (T Berk)]

Ryan H wrote:
> > On Thu, 27 Mar 2003, T Berk wrote:
> >
> > > Ryan H wrote:
> > > >
<snip>
> > > > know, there has to be some wire with a basic signal 
> > > > (12V or 0V) for knock, so I can hook an LED up to see 
> > > > when knock is present.
> > > > Anyone already try such a thing?
> > > > ___________________________
> > >
> > > <http://home.mindspring.com/~tberk/index.html>
> > >
> > > Can these schematics help any?
> > >
> > > TBerk
> > >
> > One way to do it is via  a compare ckt.
> > if the output of the CIS box == output of the knock box no knock.
> > if != retard occuring.
> > brian
> 
> Brian: Sounds a bit too complicated to make... although I'm no electrical engineer.
> TBerk, your schematic is pretty good, so maybe you have some ideas - do you think a 12v LED with the positive lead to pin 13 would do anything?
> 

I would be concerned with signal drop if you just hook up an LED, I'd
want you to wrap a coil around the signal wire (#13) and use it to
trigger an LED circuit.

Wait, all that would do is flicker when the mic that is the K/S was
fed ping. Better yet would be to get a signal from when the K/S box
goes into action, lets see...

<http://home.mindspring.com/~tberk/_uimages/Knock-Sensor-Diagram.JPG> 
Looking at David's pic I see a test port on pin #4, this might be what
your looking for.


TBerk