60 Threads found on edaboard.com: Coil Measurement
Is there a recommended way of measuring the parasitic capaictance of an inductor coil or planar inductor?
Any advice is appreciated :)
Analog Circuit Design :: 24.03.2006 04:58 :: Catalyst :: Replies: 2 :: Views: 1358
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 ).
RF, Microwave, Antennas and Optics :: 16.05.2006 09:45 :: AndrzejM :: Replies: 9 :: Views: 1805
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
Electronic Elementary Questions :: 23.05.2006 03:33 :: ifelix :: Replies: 0 :: Views: 552
I found a transformer with cutoff wires, I want to use it , but primary coil has 3 leads:
red, blue and brown. So which pair to connect to 220V?
Resistance between are as on are there 3 leads, none is connected to the iron core.
Analog Circuit Design :: 28.02.2007 09:40 :: jhanus :: Replies: 12 :: Views: 653
i need some answer about.....
1)what type of wire or coil is used for the antenna of rf transmission
2)i have collected some wire and made them a loop of square shape and for measuring its inductance applied it in a rlc circuit.but its not showing any significant value...how can i measure the inductanmce of this coil??
i am trying to tran
RF, Microwave, Antennas and Optics :: 14.07.2007 14:44 :: tanzil_dhk :: Replies: 3 :: Views: 855
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
RF, Microwave, Antennas and Optics :: 28.08.2007 14:51 :: jallem :: Replies: 3 :: Views: 1024
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
Electronic Elementary Questions :: 19.04.2009 02:46 :: chrisbris :: Replies: 1 :: Views: 2894
It should be noted, that the suggested "transformer" doesn't behave like a ususal current transformer. In the frequency range of interest, the said "proportinate voltage" is actually proportional to the current differential di/dt. It must be integrated to achieve a frequency and waveform independet current measurement.
Furthermore, the coil isn'
Analog Circuit Design :: 15.05.2009 01:37 :: FvM :: Replies: 6 :: Views: 3869
How can I measure the impedance of a small coil like the attached photo? coil is 2mm coper wire located inside a quartz tube (4 mm diameter for water cooling). coil diameter is 2.5 cm and lenght is 2.8 cm both like this and while plasma is ignited and coil is
RF, Microwave, Antennas and Optics :: 29.09.2009 02:27 :: steve_rb :: Replies: 5 :: Views: 1130
anyone know what's important we need to calculate single layer air coil inductance
and how to calculate air coil inductance?
Electromagnetic Design and Simulation :: 04.01.2010 02:41 :: kyg :: Replies: 1 :: Views: 2303
I could be way off on this, but it seems that if you want to measure current, wrap a coil around the hot wire and measure the induced voltage. With a current from 0 to about 2.5 amps you should have no problem measuring a voltage.
Analog Circuit Design :: 22.04.2010 22:50 :: eanema :: Replies: 6 :: Views: 1711
how can i measure the inductance of a coil .
Analog Circuit Design :: 29.04.2010 13:29 :: judfid :: Replies: 6 :: Views: 1731
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
Power Electronics :: 12.10.2010 19:53 :: Mr.Cool :: Replies: 11 :: Views: 843
I am measuring the Q factor of a coil with a VNA using two methods.
Do I need to have an impedance match for the weekly coupled small coils connected to the VNA. According to what I understand, no impedance matching is needed.
Is this correct?
RF, Microwave, Antennas and Optics :: 16.03.2011 14:45 :: icpinu :: Replies: 6 :: Views: 1237
I'm under the impression, that the pulse CX2041NL may be better suited for 10 MHz range than mini-circuits TCM1-1 due to it's wider frequency range. But basically each of them should work, if you apply standard open/short/load calibration at the transformer secondary. A general problem with balanced network analysis is the unknown common mode to di
RF, Microwave, Antennas and Optics :: 31.03.2011 17:34 :: FvM :: Replies: 6 :: Views: 1711
A coil placed near the motor might pick up a sinewave by induction.
You might have to experiment with different types of coils (low vs. high inductance, containing iron vs. containing none, etc.).
You might have to try it in different locations (near windings, near an opening in the housing, etc.).
Professional Hardware and Electronics Design :: 22.06.2011 05:02 :: BradtheRad :: Replies: 4 :: Views: 1168
Please see whether this paper from coilcraft is helpful.
Electronic Elementary Questions :: 09.12.2011 06:37 :: mvs sarma :: Replies: 7 :: Views: 2888
I would like to know how can I measure the ampere of a coil, if for example I know the wattage of the coil is 200 watt and the resistance of the coil is 500 ohm and it works on 24 VAC so how much current will it uses? so i can decide type of cable to use.
Electronic Elementary Questions :: 25.04.2012 05:46 :: mohamed.elsabagh :: Replies: 6 :: Views: 498
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
Electromagnetic Design and Simulation :: 30.05.2012 04:17 :: mr_monster :: Replies: 2 :: Views: 250
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
Analog Circuit Design :: 27.09.2012 05:57 :: jiripolivka :: Replies: 2 :: Views: 332
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
Analog Circuit Design :: 04.11.2012 06:28 :: FvM :: Replies: 1 :: Views: 483
For $20 I would buy the correct one, you need a special machine or a LOT of time to wind toroid coils!
Electronic Elementary Questions :: 08.11.2012 12:43 :: chuckey :: Replies: 2 :: Views: 353
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
Power Electronics :: 17.12.2012 00:58 :: ismu :: Replies: 3 :: Views: 234
Additional to the classic current transformer method, there are now available devices which look like current transformers in that they generally have a toroid form that you pass the current wire through, (optionally with more than 1 turn), but are Hall-effect sensors. Some simply amplify the sample, other more accurate types use a null coil and a
Electronic Elementary Questions :: 28.05.2013 17:32 :: Darktrax :: Replies: 2 :: Views: 684
Use a rogowski coil.
Analog Circuit Design :: 01.08.2004 19:14 :: Beetroots :: Replies: 4 :: Views: 977
If you are operating in sea water, there is a proven method. Naval vessels use a detector called a Rodmeter.
The rodmeter is a coil inside a waterproof sheath. On the surface of the sheath are two contact buttons. A constant magnetic field is established by the coil.
- As the vessel moves through the water, the conductor (seawater) is cut
Microcontrollers :: 12.01.2005 16:04 :: House_Cat :: Replies: 12 :: Views: 3172
You need to put a resistor between the uc and the bjt. This will limit the current and put less stress on the uc. You can use a darlington pair of transistors to get more current gain.
As a test, hand hold a wire between the collector and emitter of the bjt and see if the relay closes. You need a diode across the relay coil pointing towards
Microcontrollers :: 21.06.2005 00:35 :: flatulent :: Replies: 2 :: Views: 508
10 turn coil should have full DC supply voltage if not oscillating. Check 215V supply without a load and when loaded with oscillator. When oscillator is not running it may draw significant current and overload supply. It could be a reason that you have only 100V. The reason why oscillator is not working can be wrong connection of transformer windin
Analog Circuit Design :: 02.08.2005 22:43 :: Borber :: Replies: 12 :: Views: 1145
You can control an AC device using a relay. The important relay parameters are:
Maximum contact voltage. Contact voltage ratings are different for AC and DC loads.
Maximum load current. Relay current ratings are different for resistive, lamp, inductive loads.
The coil drive voltage that is available. Relay coils come in various
Electronic Elementary Questions :: 08.02.2006 14:56 :: Kral :: Replies: 5 :: Views: 1680
Most common way is to use two coils of wire. They must be isolated and work like transformer. Feed first coil with some small AC voltage, measure feedback from second coil. Once you put some metal object near coils you will have a change in second coil output. Size of coils, number of turns, (...)
Professional Hardware and Electronics Design :: 17.11.2007 13:18 :: Zman :: Replies: 1 :: Views: 1204
I use digital meter and when two point is completely electrical isolation than it display "0.L", I always think that.
That circuit is the power supplier for computer, it is decayed, I did testing probe on the primary coil of transformer and see that. That voltage is fed from a voltage rectifier, 220VAC to 250VDC.
Electronic Elementary Questions :: 23.11.2007 09:51 :: smiles :: Replies: 3 :: Views: 539
I know that the reactance of the input coil on the GSM Sniffer is almost a short circuit at lower frequencies but doesn't it pickup every radio station, television station and taxi-cab radio in town?
Doesn't it also pickup mains hum and light dimmers?
Hobby Circuits and Small Projects Problems :: 26.12.2008 09:43 :: Audioguru :: Replies: 5 :: Views: 1911
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
Electronic Elementary Questions :: 12.01.2009 10:23 :: ECM :: Replies: 5 :: Views: 6427
I didn't except a low frequency RFID system. In this case, the situation is somewhat different.
You don't have matched RF antennas rather than tuned inductive coupler coils with 125 kHz (and also mostly with 13.56 MHz RFID). To monitor system operation without disturbing the field, you can either use a very small test coil (one or a few windings
Digital communication :: 03.07.2009 02:35 :: FvM :: Replies: 5 :: Views: 952
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. (...)
Analog Circuit Design :: 25.08.2009 07:41 :: UroBoros :: Replies: 2 :: Views: 3804
I think, the application note answers most of your questions. I don't see the circuit as a totem-pole output. It's rather a bipolar current pulse generator with independent control timing for both drivers. The application note additionally suggests a circuit with active current limiting. But I agree, that there are some unclear points in the AN. Th
Hobby Circuits and Small Projects Problems :: 03.10.2009 10:15 :: FvM :: Replies: 3 :: Views: 2611
You'll find rules of thumb in RF handbooks and amateur radio literature. For complex geometries, e.g. PCB coils, I prefer a measurement or a numerical simulation. FastHenry from is a good free tool.
You'll need a method to fine-tune the circuit after making it, so an oscilloscope and either a signal generator or
RF, Microwave, Antennas and Optics :: 31.10.2009 04:30 :: FvM :: Replies: 6 :: Views: 3824
Seriously, the question for best method can't be answered without a full specification. An AC only measurement generally
suggests a current transformer or di/dt sensing (Rogowski) coil. Both provide high bandwidth, isolation and low interference
susceptibility, the latter also insensitiveness to DC currents and effectively unlimited overload ca
Analog Circuit Design :: 08.11.2009 04:57 :: FvM :: Replies: 9 :: Views: 4466
This measurement envyronmet called: GDO...
(GridDipOscillator, & as hes name tels us, it is a very old, so ca. 80-90 years, technique)
What you need:
a sweeped signal generator (in your checked fequencies) with a relative small, but wideband coil as antenna, than if you are with them over your TX/RX(exactly a tuned-swinging coil) (...)
Digital communication :: 01.01.2010 15:54 :: karesz :: Replies: 1 :: Views: 647
Strictly spoken, only a current transformer scales down a current. A shunt resistor in contrast converts the current to a voltage, a di/dt sensor (rogowski coil) generates a voltage proportional to the current change in time.
Embedded Systems and Real-Time OS :: 02.01.2010 04:56 :: FvM :: Replies: 5 :: Views: 937
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 (...)
Power Electronics :: 12.02.2010 16:28 :: FvM :: Replies: 3 :: Views: 1206
Why don't you use a Rogowski coil to measure the current.
Analog Circuit Design :: 16.02.2010 02:24 :: sakhan :: Replies: 7 :: Views: 2807
I am currently doing a undergraduate project in my university and need some help rgd my circuit design. I am trying to experiment with resonant inductive transfer to wirelessly transmit power.
The setup is:
I have a load which is an LC circuit with a capacitor connected in parallel to a copper coil. I need to drive power into this LC c
Analog Circuit Design :: 08.06.2010 13:36 :: naveenlp :: Replies: 5 :: Views: 996
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
Analog Circuit Design :: 21.09.2010 17:45 :: cdrrck24 :: Replies: 6 :: Views: 1249
You may want to tell about the time constant of the said capacitor-coil (LRC) circuit, but according to the switching speed of most coils, I won't expect more than a few ten or maximum one hundred ms. So obviously, the involved frequency range is much above "zero" hertz. Actually, it isn't too far apart from usually specified ESR frequency range.
Analog Circuit Design :: 01.05.2011 18:02 :: FvM :: Replies: 14 :: Views: 1495
At first sight, both "strange" waveforms seem to indicate RF oscillations of the power stage. This would be actually another expectable result of placing an inductive shunt into the source connection of a power stage transistor.
The waveform marked as "O.K." is showing a considerable amount of negative mutual inductance. It's far from resemblin
Power Electronics :: 04.11.2010 18:04 :: FvM :: Replies: 13 :: Views: 1390
I have the device that comes with the chips that reads and writes to the chips.
In this case, you can wind of few wire turns as a montor coil, connect an oscilloscope and try to detect the carrier frequency as a first step. To identify the protocol, some deeper knowledge of RFID would be needed. You can find introducing literature a
RF, Microwave, Antennas and Optics :: 03.12.2010 18:45 :: FvM :: Replies: 4 :: Views: 849
The best way is to use larger diameter coils on both ends of the link.
RF, Microwave, Antennas and Optics :: 13.12.2010 12:23 :: flatulent :: Replies: 5 :: Views: 1267
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
Microcontrollers :: 31.05.2011 09:04 :: FvM :: Replies: 3 :: Views: 516
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.
Electronic Elementary Questions :: 20.12.2011 12:12 :: ark5230 :: Replies: 7 :: Views: 461