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24 Threads found on Coil Measurement
Please elaborate, where doe you see a "spike", how do you measure it? Turning a relay on will generate no spike on the coil side, the back emf during turn-off can be safely shorted by a freewheeling diode. May be you see contact arcing noise coupled into your measurement setup?
Maybe an ultrasonic sensor will work, if someone is holding the rfid tag it will detect their hand as well. The return magnetic field variation from the rfid tag varies a lot depending on the orientation of the tag relative to the reader, it works best with the reader coil perpendicular to the reader coil.
Hi, Is anyone have in idea how i can measure BH curve of single inductor coil.I have this non-linear inductor with inductance of 500uH and resistance of 15Ohm. Regards, Umesh
We have to set up a three phase, 650W BLDC pump motor. It must spin at 8000RPM constant speed, and pump fuel. Each of the three motor coils has an inductance of 56uH, and resistance of 16mR. I calculate that in between the commutations from coil to coil, each motor coil should he high frequency PWM?d at around (...)
Hello all, I am new to HFSS and I am not familiar with the settings I have to do for SAR measurement. I have finished my surface coil design and got the S-parameter now I need to use the frequency of 63.87 MHz as the solution frequency to obtain the SAR inside a phantom which I have placed above the radiating coil. I have given the (...)
You've mentioned the commonly used "passive" options in your first post. They'll often require a signal amplifier, but the sensor element itself is passive. Rogowski coil is another possible passive option, a magnetical sensing method without a core.
Hi! I`ll work with for very first time. I want to use it for current measurement through current transformer. I have current transformer with impedance of 50 omhs and transformation ratio 50A to 0.05A on the secondary coil. Can you give m
Any body know about how can i measure the load through Mosfet(parallaly connected) without using CT coil and Hall effect sensor . i mean am going to switch this mosfet through 50Hz square pulse and load may be approximately > 2KVA (so shunt res not possible to measure load). i want to know, how to find the load across mosfet .here accuracy is n
The mathematic can be found at Wikipedia Rogowski coils have no magnetic core. HV capability is a matter of insulation, which can be chosen according to your needs. Several application notes and basic literature can be found here See also:
As you should learn and then find a solution, I can recommend the easiest way (I also worked with shaking tables). Connect an analog sensor to an oscilloscope. Shake the table to see sensor response. As a sensor, you can use a piezo element coupled to the table and its base so it can be lightly bent by shaking. You can use a coil with a magnet cor
I have an Inductor and I ran a scan form 20Hz to 20KHz on an impedance meter and got very strange results. I measured L and |Z| and for starters got very different results than my DVM which is measuring in 270Hz. The plot starts with a value of 770mH @ 20Hz and goes up to around 950mH @ 20KHz, but the higher the freq. the more the inductance change
It is interesting that all analogue measurement devices are RMS value reading devices because of the working principle with a moving coil in a magnetic field.
Usually, a magnetic clutch is activating the compressor. It should consume a few amps. A current relay, e.g. formed by a reed contact with a coil, can be used to sense the current. Probing the switched voltage would be still the most easy way. An inductive proximity sensor has nothing to do with current measurement. As the name reveals, i
i actually did this once, for 600V bridge with 100A throughput. i used rogowski coil as FvM suggest (the green sense wire comes in all sizes). it only measures AC current, so keep that in mind, but it has huge bandwidth. the voltage measurement is tricky.. especially if you want accuracy. the voltage is dynamic and in a high noise environment
Hello, Im trying to design a circuit that would hold a small coil, about the size of a penny at 200 Celsius. Also trying to keep the size and cost way down. I believe I should be using a Thermistor but I'm not 100% sure, I checked out the temperature controlled fans but had some trouble, is it possible someone could put me in the right directi
Your description seems to demand a constant current control loop, so you would have to provide current measurement and a PWM controller. With a contactor, the current is only limited by the "very low resistance" of the coil. Or is it just O.K. to connect the coil to a 150V supply and operate the H-bridge as solid state switch? The 50 (...)
hello everyone, anyone know what's important we need to calculate single layer air coil inductance and how to calculate air coil inductance? Thanks, kyg
I need to wind a toroid of 330uH for the output coil of a switcher (LM2576). By formula calculator and measurement I have reached a coil design. But I have to consider saturation current also before finalizing .How to do that? Saturation flux of my ferrite material as per datasheet is 480. My inductor needs to handle 2Amps. (...)
hi guys im not sure if im in the right place here but im kinda stuck on one of my trade test questions that is what causes the difference in current measured and current calculated in an ac contactor coil and explain.. something to do with reactance? any help would be greatly appreciated cheers chris
Did some searching of the forum, but didn't find an answer to my question. If you used an ohm meter, and measured across a solenoid coil are you measuring the resistance of the coil or the reactance? What I want to do is calculate the inrush and holding currents of a solenoid valve in a 24V AC 60 Hz application. So if I take a measurem
It does not look like the antenna is a balance sctructure, does it?.........If that is the case you do not need a BALUN. But what it looks weird is the coil you have put in the middle, why? Matching?....You can do with small lumped 402 devices. For other hand the coil and the long thin traces will be part of the antenna. I would recommen
Hi. I've a little practical question. I've measured in anechoic chamber the input impedance of a coil loaded monopole resonating near 487 MHz. I've calibrated the Network Analyzer up to the point where I've attached the antenna. My need was to determine the input impedance of the antenna so I take a measurement of the magnitude and of the phase o
The solution could be a dual channel oscilloscope in differential signal configuration. Common signals should be canceled (if the probes in both channel are identical) but the signal from the coil should be displayed. (This could be a solution in low frequency range, I am not sure if it will be effective at 10 MHz ).
Hello, Is there a recommended way of measuring the parasitic capaictance of an inductor coil or planar inductor? Any advice is appreciated :) Kind Regards Cat