need help to use optascoppe whit 24 volt signal
dechief michel
Posts: 75
Hello everbody,
at first, i would to appologise for my bad english ( or american ) langage knowledge.
I'm from Belgium and i use normally the french langage (but also flemish or german, sometime also: russian).
My problem is:
I'm working as a high gradueted engineer for heart moving materals, as crane or buldoozer by sample.
My object is to use the optascoppe to take some measurement on this kind of machine.
Unfortunatelly optascoppe just accept signal to a maximum of 20 volt peak to peak.
On to my job i have to take measure to 24 or maybe till 28 volts when alternator i charging.
My question is:
could you help me to develop a fine voltage reducer to take measurement above 20 volt.
Channel B give me opportunity to record as data sheet my informations, its great but i need 2chanel to be recorded, how can i adjust channel a as a recorder fr data.
Many thanks for your answer and welkom to you if you are coming in Belgium
Michel Dechief
Engineer
Professor at at university of Brussel, also at International school of Brussel.
at first, i would to appologise for my bad english ( or american ) langage knowledge.
I'm from Belgium and i use normally the french langage (but also flemish or german, sometime also: russian).
My problem is:
I'm working as a high gradueted engineer for heart moving materals, as crane or buldoozer by sample.
My object is to use the optascoppe to take some measurement on this kind of machine.
Unfortunatelly optascoppe just accept signal to a maximum of 20 volt peak to peak.
On to my job i have to take measure to 24 or maybe till 28 volts when alternator i charging.
My question is:
could you help me to develop a fine voltage reducer to take measurement above 20 volt.
Channel B give me opportunity to record as data sheet my informations, its great but i need 2chanel to be recorded, how can i adjust channel a as a recorder fr data.
Many thanks for your answer and welkom to you if you are coming in Belgium
Michel Dechief
Engineer
Professor at at university of Brussel, also at International school of Brussel.
Comments
·· You will need to use a resistor divider to bring the voltage down to within 0-10V, so use a divide by 3 resistor divider.· I hope this helps.· 30V will show up as 10V on the Scope if done properly.· 15V would show up as 5V, etc.
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Chris Savage
Parallax Tech Support
csavage@parallax.com
but could you inform me of the value of this kind of resistor and also maybe a little schematic to use it.
Thanks by advance
Michel from belgium
·· I'm not sure what your skill level in electronics is, but based on what you said you were doing I·was hoping·you would know what I meant.· At this point I guess the simplest way to demonstrate without going fully into details would be to use 3 1M Ohm resistors in series...One end will connect to your voltage input, and one end will go to ground.· From the end that goes to ground if you tap into the next junction (Between the first and second 1M resistor) you will see about 1/3 of the input voltage.·
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Chris Savage
Parallax Tech Support
csavage@parallax.com
certainly i understaind what you wrote but my answer was about (value) means tolerance.
I think to keep a little bit accuracy in to my measurement i need to use resistor of 1% tolerance for a approximative realiable test.
it's very difficult to find this kind of component here in Belgium speciffically for little order(3 pieces).
So , maybe you know a integrated circuit whos perform to this kind of obligation.
When you say in your last message:"you will see about 1/ 3 of the input voltage" the term about is damaging my scientific character. I never said about but just only: exactly.
By a another hand, whats about the possibility to use channel A also and into the same time of channel B as data recorder.
Question of my skill levell in electronics take some reference in to my books(l'
·· I was offering a work-around.· If you need that kind of accuracy at those voltages, you may have to use a scope designed for that application.· Sorry I couldn't be of more assistance.
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Chris Savage
Parallax Tech Support
csavage@parallax.com
If you cannot buy 1% resistors easily, there is a simple alternative.
If you have a precision VOM, just measure the lower rated resistors you have and create a spreadsheet in your personal computer. It is a linear conversion, so I am sure it is easy.
Generally, the resistors do not change value suddenly. Nor do they change greatly over temperature changes [noparse][[/noparse]you can warm them up if you are concerned]. 5% just means that it is within 5% of the label.
While it is nice to have simple numbers, for highly accurate work this may be the best choice. The new digital VOMs are far more accurate than the resistor labeling. Many of the skills involved in accuracy are about knowing what to accept as reliable, not really about 'buying accuracy'.
Good luck.
Post script.· I have done large earth moving projects and had to estimate productivity cycles for bulldozers, loaders, etc. so I am interested.· A lot of the motion is very repetative and tiresome for the operator.· If the machine can learn a pattern and follow it, it frees the operator to observe saftey concerns in his work.
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"When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)
······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
Post Edited (Kramer) : 11/8/2005 3:06:55 PM GMT