HI
i WANT TO READ HIGH AC VOLTAGE at analog input.
Kindly suggest.
I have seen the 220v AC demo but i need to work with high voltages.
thanks.
Do you have enough knowledge to handle high voltages? AC at these voltages may be lethal!
What kind of voltage do you want to measure? The high voltage of an electric fence is completely different from electric mains and that is completely different from the high voltage part of a geiger counter.
pylon:
Do you have enough knowledge to handle high voltages? AC at these voltages may be lethal!
This is very likely one of those typical cases of "if you have to ask, you're not up to it"...
Hi yes actually i want to read voltage for the industrial equipment, like three phase also.
as industrial equipment mostly take 400 and above volts for working.
I need to read these voltage values to show on panel boards and need to swithing purposes.
hope i ask more clearly.
Thanks.
Don't touch these cables! Obviously you're neither experienced nor educated to handle such voltages. This is not stuff to play with! One handling error and you're dead.
OK, given the safety warnings above, regular industrial 415V 3-phase is just 3 240V circuits. So guidelines that work for 240V will also work for 415V. Regular little plugpack transformers (if you can find actual transformers and not switchmode) will work.
If higher than that voltage, then you require specialized knowledge. I suggest you call a qualified electrician and tell him what you want.
step down transformers. measure input with a calibrated voltmeter, measure actual stepped down result, calculate true step down, use that as a fudge factor in your calibrations and measure the stepped down results.
First put our names in your will and let us know where the funeral will be! The first and foremost is do you have experience at these voltages, if not you must get somebody with the experience to help you or my first statement will become necessary. From the voltages you mention it appears your working with 3 phase power and that is what I am assuming as you did not state. Yes you need appropriately rated transformers to drop the voltage to something you can work with maybe in the 10V range. Your insulation needs to be rated about 1000 Volts above the voltage your working with, check with the local authorities to validate the number. Second realize each of these AC voltages will be 120 degrees out of phase with each other. You will need to rectify the transformer outputs and add a low pass filter to clean them up. The design of this filter needs to take into account the response you need plus any external loading. Unless you need to do something beyond a voltage readout simply buy the appropriate meters, they are not that expensive and you will probably live longer. This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil
As others have suggested the safest method of making these measurements is to use an isolated stepdown transformer(s).
If your 700 volt measurement is real, you should get a 1000V input stepdown transformer. The secondary voltage should be in the 5 to 10V range. I'm not sure how many options you will have.
The reason you want to have a transformer with a rated input voltage higher that you need is; if the designer goes a little light on the iron, the output will somewhat non-linear at the higher input voltages.
Next questions are:
-
How accurate do you need the measurement? Caution, an answer of as accurate as possible will immediately cause me to assume you have no idea what you need.
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Do you need an RMS reading or will a simple average suffice?
Also the transformers will have to be installed by a licensed electrician.
John
The cheapest way is to MODIFY the current transformer to sense voltage ($5 from ebay).
enjoyneering:
The cheapest way is to MODIFY the current transformer to sense voltage ($5 from ebay).
The cheapest way for what? To kill yourself?
You first have to install the thing in the existing circuit, without making mistakes, and after that hope that the parts work as advertised... which with cheap e-bay parts is not a given.
You first have to install the thing in the existing circuit, without making mistakes, and after that hope that the parts work as advertised
Excuse, excuse. Everything around us has hidden danger and can kill us. If you assemble the attached circuit correctly and test it with cautions it will have same danger as any other AC devices.
So you can measure 110AC-700AC, you just need to use the brain.
what I find humorous about this thread: I was, among many things, a journeyman marine electrician. everybody assumes everybody else knows what they know, and no more. sometimes everybody assumes wrong.
What I find funny about the professionals. They know so much that they are afraid to do something. I knew a guy with a PH in electronics, but he doesn't know how to fix a TV.
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