Trigger signal generator

[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

 

[scada]

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

=----

Take a low voltage sample of your sine wave by either a voltage divider or a
transformer. Send that to the input of a zero detecting IC. The output can
be delayed, if necessary, with a 555 timer.

 

[CWatters]

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.

Use a Comparator to convert it to a square wave. Set one input to 0V and
feed the sinewave in on the other. Give the comparator just enough
hysterysis to make it immune to any any noise on the sinewave.

http://home.cogeco.ca/~rpaisley4/Comparators.html

 

[Alexander Frey]

Am Tue, 30 Aug 2005 15:09:44 +0200 schrieb CWatters

Use a Comparator to convert it to a square wave. Set one input to 0V and
feed the sinewave in on the other. Give the comparator just enough
hysterysis to make it immune to any any noise on the sinewave.
http://home.cogeco.ca/~rpaisley4/Comparators.html

Thanks, I'll try this one.
It seemed to me that this was a pretty simple and common task and I just
thought that there should be plenty of little gadgets out there that do
this job.

 

[CWatters]

Thanks, I'll try this one.
It seemed to me that this was a pretty simple and common task and I just
thought that there should be plenty of little gadgets out there that do
this job.

Just one follow up... The output from a comparator will be a square wave ok
but it will swing between the power rails (eg -VCC to +VCC). The device you
are trying to trigger may need a logic level signal (eg 0-5V) square wave.
You can fix this several ways but let us know if you need help with that.

 

[CWatters]

Just one follow up... The output from a comparator will be a square wave ok
but it will swing between the power rails (eg -VCC to +VCC). The device you
are trying to trigger may need a logic level signal (eg 0-5V) square wave.
You can fix this several ways but let us know if you need help with that.

I lied.. another follow up....

If you want to be able to adjust the circuit so that the trig point varies
you can wire up the comparator so that instead of switching at a fixed 0V it
switches at a variable point on the waveform. Instead of connecting one
input of the comparator to 0V connect it to a potential divider.