Oscilloscope usage

McFluffin, Wed Jun 07 2006, 07:32AM

There has something been bugging me about using my oscilloscope. I see people often get traces from pulsed power, etc from their scopes of one time events. When I tried to look up how to do this, the best I saw was that you can set things like an external trigger or play around with the threshold voltage for the sweep. However, these only provide a quick sweep on an analog scope which will quicly disapear. Is it possible to preserve the sweep of a one time event on an oscilloscope without using something like a memory tube oscilloscope? I am pretty sure I would be able to do this if I had a digital oscilloscope, but thats a little beyond my budget. I have a Tektronix 2213 if that helps anyone.
Re: Oscilloscope usage
ragnar, Wed Jun 07 2006, 07:50AM

You could try and find an "oscilloscope camera" or use a digital camera with medium exposure to capture the pulse...
Re: Oscilloscope usage
Desmogod, Wed Jun 07 2006, 07:56AM

You have a CRO, not a DSO.
a DSO has this ability, or as BP says, take a picture of it.
Re: Oscilloscope usage
Dr. Shark, Wed Jun 07 2006, 09:05AM

There are some lower price storage oscilloscopes around, but the problem is that they tend to sample real slow. I have got one that only takes a sample every 10us or so, even though it is supposed to be 20MHz. There are also some cheap computer scopes, which connect via USB or so, but they are also too slow.
Photographing might be a way around, but since you dont get a lot of light in a single sweep, and CRO screens are not very bright anyway, you should be prepared to put some kind of light-proof box between the screen and the camera, and bum up the ISO real high.
Re: Oscilloscope usage
HV Enthusiast, Wed Jun 07 2006, 11:24AM

The tektronic 2430A is a good inexpensive digital storage oscilloscope.
Re: Oscilloscope usage
Carbon_Rod, Wed Jun 07 2006, 06:46PM

Actually in the days before I had a logging scope or built the raw IR optical data logger project I used:
1.) A triggered sweep and a WinTV video capture card ($58) at a full 29.97 fps with a common CCD camera ($34) (most web cams are 15 to 25 fps.) Start capture and wait a few seconds for the codec to start dumping the feed. Again in half resolution the scan-line descaling issue is not a problem ;]
2.) Then export the raw AVI into a numbered image sequence if higher resolution zoom inspection was needed in an image tool.

I thought a crude logging scope for under a hundred bucks was fun, But as EVR pointed out there is equipment around to do this now– IIRC even some low cost midrange portable meters can do logging.

Cheers,