Trigger signal from sine wave

[Alexander Frey]

Hi all.

I want to synchronize a laser pulse with an AC current (only about 1kHz)
source that unfortunately doesn't have a sync output. For the laser pulse
I need a good trigger signal, which up to now I have generated with an
oscilloscope that has a trigger output. But this signal is not very good,
probably it's 'cause the scope is not the best one.

So my question is, how do I generate a good trigger signal from a sine
signal with an amplitude about 10V-50V? It seems a pretty simple task, but
up to now I haven't found any device that does this job. Neither in
google, nor at the major test equipment suppliers. I am also not very good
at soldering, though if the circuit is very simple and the risk to screw
it is not very high I might try it.

Thanks for your help!
Alex

 

[Chris Head]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Alexander Frey wrote:
[snip]

So my question is, how do I generate a good trigger signal from a sine
signal with an amplitude about 10V-50V? It seems a pretty simple task,
but up to now I haven't found any device that does this job. Neither
in google, nor at the major test equipment suppliers. I am also not
very good at soldering, though if the circuit is very simple and the
risk to screw it is not very high I might try it.

[snip]


Half-wave rectifier + Schmitt trigger?

Chris
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (MingW32)

iD8DBQFDE6zf6ZGQ8LKA8nwRAvYoAJ4mgqoi1hgQ3g+ZsModhCkYsGH47wCfaPMO
rg2Dfo0fNKXeV4JOKpiAwUE=
=CpOW
-----END PGP SIGNATURE-----

 

[Alexander Frey]

Am Tue, 30 Aug 2005 02:48:33 +0200 schrieb Chris Head

[...]

Half-wave rectifier + Schmitt trigger?

Ok. A google search on schmitt triggers finally turns up the thing I've
been looking for. And the circuit actually seems pretty simple so that
even I probably could do it.

Thanks,
Alex

 

[Alexander Frey]

Am Tue, 30 Aug 2005 12:13:23 +0200 schrieb Jasen Betts

first off which part othe wave do you want to trigger on.
the crest (maximum voltage), zero crossing (when the voltage changes from
positive to negative), or some other point.

Actually, I need the trigger signal to drive a digital delay generator
that himself makes a trigger pulse with a variable phase to the AC. With
this pulse the laser is fired, so that I can adjust the time the laser
fires on a sample with respect to a current flowing through the sample.
So it really doesn't matter on which point of the sine wave I trigger,
because i can reach every phase position with the delay generator. But the
best point o trigger on would probably be one on the rising/falling slope,
rather than the tip of the wave I guess. As I said in another post I'll
try the Schmitt trigger curcuit.

good quality solder, and a clean soldering iron will always help
stay away from plumbers solder

something can probably be done with an op-amp chip and a few other parts.

Oops, I just ordered two hundred pounds of plumbers solder on ebay because
it was less expensive than the other type. Was that a bad idea?

Thanks folks,
Alex

 

[Alexander]

Am Tue, 30 Aug 2005 12:13:23 +0200 schrieb Jasen Betts
<[email protected]>:
snip
Oops, I just ordered two hundred pounds of plumbers solder on ebay because
it was less expensive than the other type. Was that a bad idea?

Not terrible, you can always another career if you like, for the first few
years you have enough Pb.
Something just hit me, it's something called RoHS
Especially for a new design it might be a good idea to keep that in mind. It
hit me to hard I can't get it out of my mind.
But don't be sad, it just needs some more solder practice

Thanks folks,
Alex

Good Luck,

Alexander