I want to measure a current on a 3 kV device with the Arduino without killing it 
Uhhh.... more details please -What are you measuring, is there any way you can measure a lower voltage input? You've gotta be really careful there to avoid damaging the arduino and yourself...
use toroidal current sensor, primary 2 turns secondary 10 turns - for current
DC current? AC current? What amount of current?
Steve
Wiesserfalke:
I want to measure a current on a 3 kV device with the Arduino without killing it
"A current" is a raisin like fruit that is, typically, a little bigger than a grain of rice. To measure it, using an Arduino in the vicinity of 3 kV is rather a challenge. I would use surveying techniques -- that way you won't have to invest in expensive protection gear, because you can do the measurement at a distance.
All you will need is a telescope, a stepper motor, a way to mount the stepper motor to a tripod, a platform that will mount to the top of the stepper motor, a laser tuned to a frequency for optimal current reflectivity, and a photodiode that will respond to the laser frequency. Place the tripod a know distance from the current, then mount the stepper motor on the tripod, then the platform, leveled, on the stepper motor, then place the photodiode over the telescope eyepiece, and mount the laser next to the scope, so it points in the same direction as the viewing direction of the scope, and make sure the laser beam is at the same level as the current, and that the scope has a view of the laser spot.
We will use the Arduino to step the motor so the platform sweeps out an arc that will include the length of the current. As the platform turns, an Arduino Analog input will monitor the photodiode and start a counter when it senses photons reflected back from the current. The counter will be advanced on each step, until loss of current signal from the photodiode. Apply a bit of trigonometry, and voila! The current is safely measured!
BTW: The current is already dead.
You can find a list of sources for the materials you will need at:
Note: Just a demonstration of how a vague question can be misinterpreted ;D
ReverseEMF:
"A current" is a raisin like fruit that is, typically, a little bigger than a grain of rice.
No, a currant is a raisin like fruit. A current is a body of air or water moving through other slower air or water.
But if the OP wants a sensible answer we still need more information.
Steve
ReverseEMF, sarcasm is a low form of wit. Using newbie questions as a platform to demonstrate your world-weary knowledge is just low. BTW, you left my question about measuring raisins unanswered yesterday too
Wiesserfalke:
I want to measure a current on a 3 kV device with the Arduino without killing it
Look up current transformers. If it's truly high power, high current etc..... then be careful with safety. Killing oneself is bad as killing an arduino.
Also.... minimal to no substantial details supplied usually means minimal to no details returned.
I want to meazure the current by a radiation Detector.
It has a suply Voltage of 3kV DC and I must measure Currents As samle like 10^-6 A or smaler to find out how much radiaton thear is
sorry for the lack of information
Thanks!
Wiesserfalke:
I want to meazure the current by a radiation Detector.
It has a suply Voltage of 3kV and I must measure Currents As samle like 10^-6 A or smaler to find out how much radiaton thear issorry for the lack of information
Thanks!
You do realize that current is not continuous, but only happens the instant the particle ionizes the gas, and then it is gone.
Paul
yes i know its only for a 100 of a sekund thear thats the reazen why i want it to digitiz so I can make the calculation about how much radiation thear is more accurate
Tobi
Wiesserfalke:
yes i know its only for a 100 of a sekund thear thats the reazen why i want it to digitiz so I can make the calculation about how much radiation thear is more accurateTobi
So, what do you want to capture:
- The peak current of each event?
- Some sort of Integration of the current over time? Assuming there is a current decay that needs to be captured.
Peak current might be easier. But, either is going to be involved. But, to even begin to come up with a suggestion on how this might be done, I would need more information about the dynamics involved. Like, what is the quiescent current? Is it zero? And what is the possible current range? Is 1µA the maximum current, or some intermediate current? And, between detection events, is there 3kV present on the point where this current would be measured? A diagram would really help, in fact is pretty much crucial, since a mere description is so prone to misinterpretation.
Off the top of my head -- shot-in-the-dark -- I'm thinking in terms of a current differencing amp (i.e Norton Amp), like the LM3900. With the correct input resistors, 3kV is no problem. And, if, indeed, it's a varying current we are dealing with, the Norton Amp is well suited for that -- if the polarities are amenable. The output of the Norton Amp to an Analog input on the Arduino, which would just sit there and sample the voltage, over and over and log the result. Then, perhaps some math or calculus [like an Integrator] could be performed to come up with a usable result -- that, could, in turn, be serialized and opto-isolated to something else, that would allow reading without a shock hazard. Just off the top of my head.
Are you sure it is not about 3 KW?
I would simply run away as far as possible from a 3kV power supply.
If it is about current lines (wires that transport electricity from one geographical area to another), then it turns to measuring electromagnetic field and not the current as such - IMAO. The accuracy of indirect measuring the current in such circumstances (high voltage, Arduino platform) is questionable- again IMAO.
I would also like to stress that Arduino is a learning platform. So, perhaps starting by measuring smaller electromagnetic fields (like the ones from the house power supply) may be a fun (and reasonably safe) way to learn.
falexandru:
Are you sure it is not about 3 KW?I would simply run away as far as possible from a 3kV power supply.
I would also like to stress that Arduino is a learning platform. So, perhaps starting by measuring smaller electromagnetic fields (like the ones from the house power supply) may be a fun (and reasonably safe) way to learn.
Good point. 3kV is not for the beginner...though, I suspect it would be safer than the house power supply! I'm guessing that 3kV supply, as dangerous as it sounds, is far less capable of producing lethal currents as is the mains supply!
But, in fact, NEITHER should be toyed with!
And BTW: It's current that kills you, not voltage. If it were mere voltage that was lethal, then people would be dropping dead from a static electricity zap!
I was talking about 220V/110V house supply wires into the walls -to detect (and measure).
falexandru:
I was talking about 220V/110V house supply wires into the walls -to detect (and measure).
OH, I see what you mean. Using a non-contact method. You did mention electromagnetic detection -- my bad 
falexandru:
Are you sure it is not about 3 KW?
Oh, and I missed that you said KW and not KV. No, I doubt it's about kilowatts. A radiation detector usually has a high voltage supply to power the Muller Tube.
I dare to say that from one line question is hard to hammer an opinion.
Still, the generic question has its own merit, IMAO: how far can we go with an Arduino board circuit and stay safe?
What are the associated risks? Maybe a brief warning paper on the web site would help.
ReverseEMF:
So, what do you want to capture:
- The peak current of each event?
- Some sort of Integration of the current over time? Assuming there is a current decay that needs to be captured.
Peak current might be easier. But, either is going to be involved. But, to even begin to come up with a suggestion on how this might be done, I would need more information about the dynamics involved. Like, what is the quiescent current? Is it zero? And what is the possible current range? Is 1µA the maximum current, or some intermediate current? And, between detection events, is there 3kV present on the point where this current would be measured? A diagram would really help, in fact is pretty much crucial, since a mere description is so prone to misinterpretation.
Off the top of my head -- shot-in-the-dark -- I'm thinking in terms of a current differencing amp (i.e Norton Amp), like the LM3900. With the correct input resistors, 3kV is no problem. And, if, indeed, it's a varying current we are dealing with, the Norton Amp is well suited for that -- if the polarities are amenable. The output of the Norton Amp to an Analog input on the Arduino, which would just sit there and sample the voltage, over and over and log the result. Then, perhaps some math or calculus [like an Integrator] could be performed to come up with a usable result -- that, could, in turn, be serialized and opto-isolated to something else, that would allow reading without a shock hazard. Just off the top of my head.
I need the peak bekaus you count how muche peaks are in a sekund and than you now how much raidiation thear is .
falexandru:
Are you sure it is not about 3 KW?I would simply run away as far as possible from a 3kV power supply.
If it is about current lines (wires that transport electricity from one geographical area to another), then it turns to measuring electromagnetic field and not the current as such - IMAO. The accuracy of indirect measuring the current in such circumstances (high voltage, Arduino platform) is questionable- again IMAO.
I would also like to stress that Arduino is a learning platform. So, perhaps starting by measuring smaller electromagnetic fields (like the ones from the house power supply) may be a fun (and reasonably safe) way to learn.
Im sure its 3 KV because the gases only ionizes when the particel hits it by 3 kV.
Tobi