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Using an Osciliscope?


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22 replies to this topic

#1 Gloyale

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Posted 09 April 2009 - 09:34 PM

Hey ya'll.....

I recently picked up an old (not TOOO old) osciliscope for examining the "crossover" action of oxygen sensor voltage. Also thought I could use it to look at the Duty C output for transmissions, and possibly Cam and Crank sensors.

Problem is, I am not really sure how to use it?

Could someone tutor me? Or have a link to a good sight to describe using an Osci to look at 12v DC PWMs?

Thanks to anyone in advance

#2 Gloyale

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Posted 11 April 2009 - 05:04 PM

bump. Nobody?

#3 grossgary

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Posted 11 April 2009 - 06:09 PM

i used to use them in aerospace engineering programs and have since forgotten everything. but even then, i used them more than understood them if that makes any sense (like your customers GL!!!!).

did you try searching at all, like just a quick google search to see what's out there? i'd probably start there or in a library. but who's got time for that right?

#4 lostinthe202

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Posted 11 April 2009 - 07:16 PM

I work at an engineering school. I"ll ask some of the EE professors if they have a little tutorial they recommend to students.

#5 nipper

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Posted 11 April 2009 - 08:20 PM

The really arent that hard to use. It's easier to show you unfortunitly then tell you since there are some variations between models as to actual controls.

Did it come with wires?

What make and model is it.

#6 ron917

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Posted 11 April 2009 - 09:20 PM

Googling "how to use an oscilloscope" brought a lot of hits.

This one is very thorough: http://www.tek.com/M.../03W_8605_2.pdf

That document is form Tektronix, one of the biggest makers of 'scopes. It is geared mostly toward modern units, but should be useful for learning what a 'scope can do.

#7 Twitch de la Brat

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Posted 12 April 2009 - 06:15 PM

Not trying to hijack, but has anyone ever used an ociliscope to view the
frequency going to speakers?
And if so have you run an LED to the output so that it lights up as the volume
increases?

Twitch(?)

#8 shadetreemech

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Posted 12 April 2009 - 06:52 PM

An oscilloscope typically will display on an X vs Y graph format. the X or horizontal direction is set by the sweep speed generated by the oscilloscope internally. You control this speed on the front panel. the vertical or Y signal is picked up by a probe. This would be your signal from the car circuit that you want to test. The voltage applied to the input needs to be matched to the probe and the input voltage range on the control panel.

What kind of 'scope do you have? Do a google search on "oscilloscope tutorial", and you will find some good sites.

#9 Gloyale

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Posted 13 April 2009 - 12:51 AM

thanks for the suggestions.

I do believe the scope is a tektronics. It's at the shop

I understand what the graph displays.

I am just a bit unsure of what some of the control settings. And I don't to hook it up in a way that is going to fry anything.

#10 lostinthe202

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Posted 13 April 2009 - 06:39 AM

You could try contacting the manufacturer, they may still have a book on it that you can get.

#11 shadetreemech

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Posted 13 April 2009 - 07:10 AM

A good source for info on older electronics is at www.bama.sbc.edu/ "BAMA" stands for Boat Anchor Manual Archive, and is a great database on older electronics, especially vacuum tube equipment. Follow the Tektronic link on the site, they may have your 'scope manual available for download. There is a mirror site for BAMA, I think its www.bama.edebris

Edited by shadetreemech, 13 April 2009 - 07:12 AM.
add information


#12 hooziewhatsit

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Posted 14 April 2009 - 12:36 PM

Basically...

The Y axis will show voltage. There will be a knob to change the volts/division that it shows. The graph on the display will be broken into divisions.

The X axis shows time. There's a knob to change the seconds/division.

Most scopes have at least 2 input channels, so you can look at up two different signals. There is another knob to show/hide each channel, and to trigger off one channel or the other. Make sure they are all set to the channel you're using.

If any of the above aren't set up right, it just won't show anything.

To hook it up, just connect the ground lead to ground, and the tip to the signal you want to measure.

You can start by hooking the probe up to the battery. You can see how changing the volts/division changes the scale on the display. At 5v/div the battery should read at just over 2 divisions.

-Dave

#13 nipper

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Posted 14 April 2009 - 06:49 PM

Tektronics is one of the best names out there, they will have a manual for it.


nipper

#14 Gloyale

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Posted 16 April 2009 - 11:21 AM

Sweet guys, thanks for the help.

I will have a chance to play with it later in the week.


BTW it is not tektronics.

It is a Telequipment. Model S54A

Soem of the probes I have for it are tektronics

Edited by Gloyale, 16 April 2009 - 11:26 AM.


#15 naru

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Posted 18 April 2009 - 10:46 AM

http://www.thevalvep...eq/telequip.htm

#16 Hondasucks

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Posted 20 April 2009 - 01:04 AM

bump. Nobody?


I can come over and show you how to work it sometime :) Just as long as you guys don't get too much drool on my SVX :lol:

#17 Log1call

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Posted 04 May 2009 - 11:15 PM

These days you can get digital gauges that can do all those measurements you mentioned, and a lot more dependably too probably.

Even better you could connect a laptop to the ecu and log all the data for reviewing later and as you compare other readings to it like time or temp or speed.... or everything your ecu reads or sends out as it runs.

What ocilliscopes are really good for though is reading really high and really fast voltages... like spark plugs, which most gauges wont do(unless you spend a fortune).. That's what I'd use it for.

#18 Gloyale

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Posted 04 May 2009 - 11:27 PM

These days you can get digital gauges that can do all those measurements you mentioned, and a lot more dependably too probably.

Even better you could connect a laptop to the ecu and log all the data for reviewing later and as you compare other readings to it like time or temp or speed.... or everything your ecu reads or sends out as it runs.

What ocilliscopes are really good for though is reading really high and really fast voltages... like spark plugs, which most gauges wont do(unless you spend a fortune).. That's what I'd use it for.


I can stream the data from OBD II vehichles on my code scanner, but no easy way to live stream data from the pre-96 cars.

Besides, O2 sensors DO produce a very fast voltage swing. Mulitmeters just show you the average, not the actual widtrh of the swing, which is important for O2 sensor diagnosis.

#19 Log1call

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Posted 05 May 2009 - 02:32 AM

Hi,
it's easy to connect to older cars these days, check out a bit of software called Evoscan or Hiscan.

O2 sensors range several times a minute, even an analouge gauge can keep up.

#20 shadetreemech

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Posted 07 May 2009 - 05:06 PM

The advantage of a 'scope is it's flexibility. You can set it up to get a live display of the spark impulse at #3 cylinder. You can sample the voltage signal from an oxygen sensor, and slow down the scan so that you can watch the variations occur. You can display the 7 megahertz amplitude modulated carrier from your WW2 vintage amateur transmitter, and control for overmodulation. And there are top-quality lab grade scopes (Tektronic or Hewlett-Packard) that sold for thousands in the mid-70's, that you can buy for a couple of hundred bucks. It's all in what you want to play with, and how much self-education you want to do. It's just a tool, but if you know how to use it, a powerful tool.

#21 mr_whirly

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Posted 07 May 2009 - 07:09 PM

Not sure if this link will work for you, its a training link at my workplace.
Its decent basic usage guide.

http://fist.faa.gov/...ining/Menu.html

#22 erik litchy

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Posted 20 June 2009 - 12:22 PM

i got one at a yard sale today for $2
is it a good one? came with 3 probes

Posted Image
after a quick brush off

http://i37.photobuck...es/IMG_2109.jpg

Edited by erik litchy, 20 June 2009 - 12:35 PM.


#23 turin

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Posted 16 July 2009 - 03:33 PM

for two bucks!!! If it works, that was a sweet deal!!!

A general comment to all oscope users:
Don't neglect the XY function. This shows the voltage of one channel on the X axis, and the voltage of the other channel on the Y axis. This is very useful if you want to see how a particular component responds to an input signal.

One of the initially difficult features of an oscope for first-timers is the trigger. On newer oscopes, there is an automatic trigger setting (and it is usually the default), but on older ones (like the one in the picture above), you may be required to set the trigger manually. The trigger is a setting that tells the oscope to sweep the trace, and, if it does not detect the trigger, then it will just sit idle. For example, if you are trying to see a waveform that swings from 0 V to 5 V on Channel 1, but your trigger level is set at 10 V on Channel 1, then you will not see the waveform. Another example: if you are trying to see a waveform on Channel 1, but you are triggering on Channel 2 (that is not connected to anything), then you will not see the waveform.

The trigger is not necessary in XY mode.

Closely associated with the trigger (actually, a feature of the trigger) is the hold off (or delay). This is especially important for slow signals. If you trigger too often, you may not get a good look at your signal.

Edited by turin, 16 July 2009 - 03:43 PM.





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