help with energy concepts 30820 oscilloscope

Thread Starter

neospam

Joined Jan 13, 2020
103
Yep, that would work.
Yes, can figure it out. On 1 v/div it reads exact voltage of course and 1.5v battery, it put a wave at 1.5 divs, @ 2v put it around 3/4 div.

I was able to solder that wire w/o removing the board. I just had to un-solder the ext tiger above it.. all good.

Few picts of what the inside look like. The ss-5702 at least what I seen in the manual, some things are not the same, many are, some are not. Nerveless useful service manual I think.
 

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Thread Starter

neospam

Joined Jan 13, 2020
103
I order a manual for the ECI 40600 function generator. Someone on ebay was selling them. They wanted close to 15 bucks.. being I cannot find a pdf for it, I purchased one. I purchased the function generator thinking it would work for testing circuit and calibration. Maybe I should have got one of those less expensive Chinese one you see on ebay?
 

Thread Starter

neospam

Joined Jan 13, 2020
103
Yep, that would work.
When I hook my DVM to Cal OUT. It supposed to be .3v. I am getting 159.8mv on my older tester and newer about 160 mv. I suspect it is reading correctly being it is pulsed, being I getting 159.8mv two different testers.

Seems like it is off quite a bit.
 

AlbertHall

Joined Jun 4, 2014
10,243
It is a 300mV square wave so it is 300mV for half the time and 0V for the other half so the dvm reads the average of about 150mV. The exact mark/space ratio will affect the DVM reading so it may be a little more mark than space.
 

Thread Starter

neospam

Joined Jan 13, 2020
103
It is a 300mV square wave so it is 300mV for half the time and 0V for the other half so the dvm reads the average of about 150mV. The exact mark/space ratio will affect the DVM reading so it may be a little more mark than space.
make sense. so a square wave DC signal, full wave is both upper and lower? Is that the right? Mark is upper and space is lower?
 
My turn, after everyone else was awake.

They have several smaller sq waves. I do not get that unless I increase my mV, to 20 or so. I was able to adjust the prob wave flat in the pict. Look at pictures and labels. The very first pic with sq waves, its showing 3 division, I accidentally had the tv-v on. It did not do anything when I moved it back to AC. Those 3 div in 1x mean anything?
TV-V is TV-vertical. It's usually about line frequency. e.g ~60 Hz. B&W was the line freq. Color changed it very slightly.
3 div is 0.3 V p-p Your on a roll.

That second pic is showing the right voltage if your probe is in x1. The probe is not compensated correctly or you have the wrong probe. I'll look at your probe specs. It should look more like pic #1 except the V/Div knob should be 10x lower.

Most of the analog dials and switches show a lot of static on the screen. Sometimes I have to wiggle them. Can I use break cleaner or should I use something else?
Contact cleaner is OK. NO WD-40! De-Ox comes highly recommended.


Yes, can figure it out. On 1 v/div it reads exact voltage of course and 1.5v battery, it put a wave at 1.5 divs, @ 2v put it around 3/4 div.
In prder to mesure the DC amplitide, you have to do a GND check first. Set scope or probe to gnd and adjust the vert position so the trace is on a line. Then DC couple it. Multiply by 10 if you have to.

When I hook my DVM to Cal OUT. It supposed to be .3v. I am getting 159.8mv on my older tester and newer about 160 mv. I suspect it is reading correctly being it is pulsed, being I getting 159.8mv two different testers.

Seems like it is off quite a bit.
With the digital tranistor Vce(sat) < 40 mV meaning, the calibrator output does not go below aproximately 40 mV. So, it could be 40 mV to 0.3 + 40 mV for 0.3V p-p. Use GND of the scope and position the GND trace on a line. Ten connect the calibrator. See if there is a DC offset. 150 mV is about 1/2 or the average. That's only 9.8 mV off? You need a 50% duty cycle as well.

Some TRMS, True RMS meters, can look at just the AC component or the AC+DC component. AC meaning time-varying portion.

How is your Calculus? On the scope, you will SEE peak to peak voltages.

Depending on your DVM and the waveform it's presented, you can get all sorts of values.

For sine waves up to about 400 Hz, you likely should get the RMS value on just about any DVM.

120 V RMS is +169 to -169 volts. Multiply 120 * sqrt(2) * 2 to get the p-p value of a sine wave.

Your other pics have the Volts/Div too low.[/QUOTE]
 

Thread Starter

neospam

Joined Jan 13, 2020
103
My turn, after everyone else was awake.

TV-V is TV-vertical. It's usually about line frequency. e.g ~60 Hz. B&W was the line freq. Color changed it very slightly.
3 div is 0.3 V p-p Your on a roll.

That second pic is showing the right voltage if your probe is in x1. The probe is not compensated correctly or you have the wrong probe. I'll look at your probe specs. It should look more like pic #1 except the V/Div knob should be 10x lower.

Contact cleaner is OK. NO WD-40! De-Ox comes highly recommended.

In prder to mesure the DC amplitide, you have to do a GND check first. Set scope or probe to gnd and adjust the vert position so the trace is on a line. Then DC couple it. Multiply by 10 if you have to.

With the digital tranistor Vce(sat) < 40 mV meaning, the calibrator output does not go below aproximately 40 mV. So, it could be 40 mV to 0.3 + 40 mV for 0.3V p-p. Use GND of the scope and position the GND trace on a line. Ten connect the calibrator. See if there is a DC offset. 150 mV is about 1/2 or the average. That's only 9.8 mV off? You need a 50% duty cycle as well.

Some TRMS, True RMS meters, can look at just the AC component or the AC+DC component. AC meaning time-varying portion.

How is your Calculus? On the scope, you will SEE peak to peak voltages.

Depending on your DVM and the waveform it's presented, you can get all sorts of values.

For sine waves up to about 400 Hz, you likely should get the RMS value on just about any DVM. One is older and the other is newer. Both had similar readings.

120 V RMS is +169 to -169 volts. Multiply 120 * sqrt(2) * 2 to get the p-p value of a sine wave.



Your other pics have the Volts/Div too low.
[/QUOTE]

not sure I understand. 9.8mv is to high with 50% offset? How do you measure peak to peak? Special volt meter?

thanks.. Going to get some de-ox.. its 15 a can, the price of my function generator manual. Have break cleaner, also have some mass air flow sensor electrical cleaner - that claims to be some sort of special electrical cleaner. Need to look at the label.

ground ck.. will try this today.

Well, never had calculus. Had 4 or more years of algebra in college, tons.. My traditional institution schooling college, CIS degree mixed both business and computers.. never went into the science part of computer engineering. But love math & science.

= little over 10 almost 11.

What does this mean? You are thinking voltages are not right. We have so many test and comments, getting hard to follow. If you want me a try a specific test let me know.
 
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Thread Starter

neospam

Joined Jan 13, 2020
103
My turn, after everyone else was awake.



TV-V is TV-vertical. It's usually about line frequency. e.g ~60 Hz. B&W was the line freq. Color changed it very slightly.
3 div is 0.3 V p-p Your on a roll.

That second pic is showing the right voltage if your probe is in x1. The probe is not compensated correctly or you have the wrong probe. I'll look at your probe specs. It should look more like pic #1 except the V/Div knob should be 10x lower.



Contact cleaner is OK. NO WD-40! De-Ox comes highly recommended.




In prder to mesure the DC amplitide, you have to do a GND check first. Set scope or probe to gnd and adjust the vert position so the trace is on a line. Then DC couple it. Multiply by 10 if you have to.



With the digital tranistor Vce(sat) < 40 mV meaning, the calibrator output does not go below aproximately 40 mV. So, it could be 40 mV to 0.3 + 40 mV for 0.3V p-p. Use GND of the scope and position the GND trace on a line. Ten connect the calibrator. See if there is a DC offset. 150 mV is about 1/2 or the average. That's only 9.8 mV off? You need a 50% duty cycle as well.

Some TRMS, True RMS meters, can look at just the AC component or the AC+DC component. AC meaning time-varying portion.

How is your Calculus? On the scope, you will SEE peak to peak voltages.

Depending on your DVM and the waveform it's presented, you can get all sorts of values.

For sine waves up to about 400 Hz, you likely should get the RMS value on just about any DVM.

120 V RMS is +169 to -169 volts. Multiply 120 * sqrt(2) * 2 to get the p-p value of a sine wave.

Your other pics have the Volts/Div too low.
[/QUOTE]

0 on display GRD before hooking probe. First pict did not show full sq, 2 pict had to scroll position down to get it in view. Is this right? What is the math of the display? It show 3 div either way, @ 5mV and 1ms re-positioned on 10x.
 

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AlbertHall

Joined Jun 4, 2014
10,243
If the line is in the middle of the screen before you connect the probe, then that is 0V. The cal signal goes from 0V to 300mV - so from the that centre line 6 divisions upwards which takes the top of the waveform off the screen. Then you can adjust the Y position to move the 0V position to three divisions below the centre line and get your second waveform.
 

Thread Starter

neospam

Joined Jan 13, 2020
103
If the line is in the middle of the screen before you connect the probe, then that is 0V. The cal signal goes from 0V to 300mV - so from the that centre line 6 divisions upwards which takes the top of the waveform off the screen. Then you can adjust the Y position to move the 0V position to three divisions below the centre line and get your second waveform.
Like what I did in the photo?

Confused yet.. I set the V to 5mV and time 1ms @ 10x probe, does not the 5mV or 10x effect the math in the 6 div spread? Time does not factor in right for voltage?
 

AlbertHall

Joined Jun 4, 2014
10,243
The 5mV/Div with a X10 probe gives 50mV/Div so 300mV gives 6 divisions deflection.
The time/div does not affect the voltage reading - it will spread out, or squish up, the waveform in the horizontal direction though.
 

Thread Starter

neospam

Joined Jan 13, 2020
103
The 5mV/Div with a X10 probe gives 50mV/Div so 300mV gives 6 divisions deflection.
The time/div does not affect the voltage reading - it will spread out, or squish up, the waveform in the horizontal direction though.
thanks, that helps...
100mV @ 1x probe = .1V div
100mV @ x10 probe = 1V div
.5V @ x10 probe = 5V div
1V @ x10 probe = 10V div
1V @ x1 probe = 1V div
2v @ x10 probe = 20V div
2V @ x1 probe = 2V div
 
What you did, is not EXACTLY what I wanted you to do.

Either set the coupling to GND or use the GND setting on your probe. You should have a straight line in auto-trigger. Move that line with the vertical position, so it's on a gratecule The calibration is aprox 0-0.3 V p-p, so set the 0 near the bottom of the screen.

Now apply the calibrate signal, DC coupled. You can muck with the level and slope controls. I THINK the bottom of the square wave will be slightly above the now invisible 0V reference that you arbitrarily set earlier. It could be as much as 40 mV.
 
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Thread Starter

neospam

Joined Jan 13, 2020
103
How come w/o adjusting anything except voltage to 10mV (from 5mV to 10mV cal setup) I get scrolling signal? If I back trigging level off a bit, it stops.
What you did, is not EXACTLY what I wanted you to do.

Either set the coupling to GND or use the GND setting on your probe. You should have a straight line in auto-trigger. Move that line with the vertical position, so it's on a gratecule The calibration is aprox 0-0.3 V p-p, so set the 0 near the bottom of the screen.

Now apply the calibrate signal, DC coupled. You can muck with the level and slope controls. I THINK the bottom of the square wave will be slightly above the now invisible 0V reference that you arbitrarily set earlier. It could be as much as 40 mV.
not sure I understand what you are saying. You said set 0 "near" bottom? Where is near bottom? I set it at, 3rd and 4th gratecule. Then you said to calibrate, this is not much different then I did before? The one picture 0 is set at 3rd div down and in the middle of the scale. The other pict, 0 is set at the bottom line and the wave is just below the measurement line. Where is this 40mV are you talking about the top of the square wave it is slightly above the gratecule (div) not sure if I am using the word gratecule right? Also, I am not sure where you wanted it lined up, I find it just below the increment is easier to see.
 

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neospam

Joined Jan 13, 2020
103
This
XYZ's of Oscilloscopes, Tektronix: http://ecee.colorado.edu/~mcclurel/txyzscopes.pdf

might help a lot.

At least your not playing with a dual trace dual time-base scope and it doesn't weigh 100 lbs.
There was someone in TX selling one of the textronic large scope with 100-200 tubes in it that was on cart with separate power supply. I think it was a 500 or 700 series scope. Its a true dual channel, it is used often to take pict. Nice to have for 170 bucks, to expensive to ship. In Carlson youtube video he has 3-4 models like that. very heavy, very nicely built machine.
 
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