Doing Without an Oscilloscope!

[jadaro2600]

The idea is to be able to do without an expensive scope and derive accurate assumptions about the waveform using equipment which can be purchased for under 120USD.

I think it would behoove us all to have such an ability to extrapolate this type of information and may help relieve hobbyists on shoestring budgets.

I have observed several multimeters which can asses the following:
Duty cycle,
Frequency,
Voltage DC and AC,

From these: voltage AC, voltage DC, frequency, and duty cycle; I think a reasonable assumption of the waveform can be derived.

I aim to find a method for doing so, and request help with the subject matter.

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One simple way to verify your AC is to test the AC voltage, ..then switch the multimeter to DC.  If there is a DC voltage, then the AC has a DC bias offset in the direction of the polarity of the voltage reading proportional to the voltage reading.

This is a[n unprofessional] way to do things but with limited resources . . .  I want to figure out a way to determine the characteristics of the waveform without having a scope or any professional ( expensive ) equipment.

As I do not have an oscilloscope, it would be nice if, when we do attempt to test the ideas, someone having one could verify the outcomes.

As it stands, the numerousness of circuits which create pulses, wobbling waves, unbalanced AC, etc creates a situation in which methodology takes precedence over a single circuit design.  Therefore, I think it unwise to attempt to match circuits diagrams and presume success without taking these things into account.

I hope to use math and perhaps a come up with some simple solutions.  Perhaps even create a Java web applet that can show an approximation of the waveform.

I know that only so much can be derived from basic measurements, however, we may also come up with a means or apparatus, which when employed, yields more data which can be taken into account.

One thing we may incorporate is the properties of the multimeter being used ( RMS ), etc, internal resistances, the list goes on.

Any additional information or ideas would greatly be appreciated, and I hope to collaborate a solution to the problem of not having the budget to afford ( say, ) a five thousand dollar shelf piece.

[dankie]

Even a professionnal engineer wouldnt do without an oscilloscope . You can always isolate the problem .

http://shop.ebay.com/i.html?_trkparms=65%253A15%257C66%253A2%257C39%253A1&_nkw=oscilloscope&_fcid=2&_localstpos=&_sc=1&_sop=15&_stpos=&_trksid=p3286.c0.m14&gbr=1&_pgn=9

[innovation_station]

yes i highly reccomend a anolog o scope ...

mine cost me 100 bucks cdn it is about 40 years old or more ... but it works great!

this tool makes this a much easyer job ... but fact !

i did not have one ... when i figured it out ...

agin if your planing on rectifing and chargeing caps... 

YOU DO NOT NEED 1 ...

simply tune your coil to the highest rectified voltage ..

works EVERY TIME  agin diodes play quite a large roll !   out of all the diodes i have laying around and i have many!  i found the 2n4001 to work darn well  as well or better then schoky diodes .. mur diodes fr diodes crystal diodes ...  there was 1 i found better that was.... the switching diode 50 for 5 bucks at RS



WILLIAM!

and if you dont want the mess of diodes ...  DB107 1000V 1 AMP !

[jeanna]

Well mine cost $189 and gives me a digital readout of the frequency and volts it is seeing. I do not need to count squares as I see so many people doing on youtube.
It is a velleman 10HPS

I learned later that the improved version of this scope with a backlight is available for $140.
So, I say go for it.

They also make a similar one with a 40Mhz sample rate which comes with a scsi attachment. But I think that one is $250.

I use mine all the time.
I put the probes on the secondary jt wires and adjust the base resistor and I know exactly the information I need immediately.
I took it outside and read the volts and frequency on my earth battery all last summer.
etc.

Make it a winter solstice present to yourself.

jeanna

[resonanceman]

The idea is to be able to do without an expensive scope and derive accurate assumptions about the waveform using equipment which can be purchased for under 120USD.

I think it would behoove us all to have such an ability to extrapolate this type of information and may help relieve hobbyists on shoestring budgets.

I have observed several multimeters which can asses the following:
Duty cycle,
Frequency,
Voltage DC and AC,

From these: voltage AC, voltage DC, frequency, and duty cycle; I think a reasonable assumption of the waveform can be derived.

I aim to find a method for doing so, and request help with the subject matter.

- - - - - - - - - - - - - - - - - - - - - - - - -

One simple way to verify your AC is to test the AC voltage, ..then switch the multimeter to DC.  If there is a DC voltage, then the AC has a DC bias offset in the direction of the polarity of the voltage reading proportional to the voltage reading.

This is a[n unprofessional] way to do things but with limited resources . . .  I want to figure out a way to determine the characteristics of the waveform without having a scope or any professional ( expensive ) equipment.

As I do not have an oscilloscope, it would be nice if, when we do attempt to test the ideas, someone having one could verify the outcomes.

As it stands, the numerousness of circuits which create pulses, wobbling waves, unbalanced AC, etc creates a situation in which methodology takes precedence over a single circuit design.  Therefore, I think it unwise to attempt to match circuits diagrams and presume success without taking these things into account.

I hope to use math and perhaps a come up with some simple solutions.  Perhaps even create a Java web applet that can show an approximation of the waveform.

I know that only so much can be derived from basic measurements, however, we may also come up with a means or apparatus, which when employed, yields more data which can be taken into account.

One thing we may incorporate is the properties of the multimeter being used ( RMS ), etc, internal resistances, the list goes on.

Any additional information or ideas would greatly be appreciated, and I hope to collaborate a solution to the problem of not having the budget to afford ( say, ) a five thousand dollar shelf piece.