The magnetics tag has no wiki summary.
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How to route Gigabit Ethernet, remote PHY or remote RJ45 connector?
I need to design a 10/100/1000 BASE-T “backplane” board that contains multiple PHY outputs from Ethernet controller chips. On the board ,the LAN specifications are very strict in regard to how the ...
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1answer
116 views
Amperian loop to measure solenoid's magnetic field
My textbook proves the formula \$B =\mu_0In \$ for a solenoid by taking a rectangular Amperian loop as shown here:
The problem I see with this though is that it only takes into account the ...
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1answer
113 views
Magnetic Encoders - Tips and Tricks
I am new to encoders in general and I am thinking about using a magnetic encoder in a personal project were I will need to make my own servo, and thus get an absolute position reading (instead of the ...
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1answer
181 views
magnetic field outside solenoid
It is written in our course book that the magnetic field outside a solenoid is negligible and almost zero. Why is it negligible? Is it negligible compared to the field inside solenoid or is it nearly ...
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1answer
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Am I following the procedure to set the sensitivity in Try Mode for the A1362 Hall-Effect sensor correctly?
I am following Figure 5 pg. 18 of this data sheet: Vp(HIGH), Vp(MID), Vp(HIGH), followed by 0-255 Vp(MID) pulses that increase the sensitivity each time Vp(MID) is applied.
However, when I bring ...
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Differences between a planar coil and coplanar waveguide to create a local 1D AC magnetic field
Coplanar waveguides (for example picture look here) are often used in research to create a local in-plane magnetic field. Now if compared to a planar microcoil like this,
driven by a AC voltage in ...
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2answers
216 views
Sensing magnetic pulses from a rowing boat impeller
I'm a mechanical engineer at uni who has some basic experience in electronics and programming. I'm building a system for my rowing boat to help me with my training. This will give me feedback on a ...
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How to choose a reed switch and magnet?
I need to use a reed switch and a magnet on a shaft. When it get turned to a specific degree the magnet will trigger the reed switch. The shaft only turns one way and is turned by hand.
The problem ...
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448 views
Ethernet Without Magnetics?
How / can you connect Ethernet devices together without magnetics? How do you wire it up? What sorts of practical limitations are there on doing this?
To clarify, I'm not trying to connect two ...
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3answers
398 views
How to convert a three wire hall effect sensor to a 2 wire sensor?
Would there be any possibility to convert a three-wire hallsensor to a 2-wire equivalent.
The connections are a V+, GDD and OUT.
The voltage between V+ & GDD would be 24V and the OUT port would ...
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569 views
What sensors are commonly used for vehicle detection?
I want to make a vehicle detection prototype. I find there are multiple choices of sensors that can be used to detect a vehicle, such as acoustic, ultrasonic, infrared, magnetic inductive sensor.
I ...
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115 views
Automobile ignition coil (spark coil)
Question: How is this possible to get 1:1000 electric potential scale while primary/secondary loop scale is only about 1:100?
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1answer
170 views
Controlling temperature of a water bath with induction plate
I am thinking of building a sous-vide cooker using some kind of prebuild heater, controled via an AVR and temperature sensor like the LM35. There are a lot of references around using rice cookers, ...
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1answer
234 views
How close can I place two transformers?
I need to place two of these transformers in a case. How close am I allowed to place them? Can they touch each other (of course, they will be electrically isolated)? Is their orientation with ...
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5answers
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Does magnetism affect SD cards?
Would a strong magnet have any effect whatsoever on a thumb drive (I'm assuming not) or on an SD card? It seems unlikely, but I'm hoping someone can give me a definitive answer, since I'd rather not ...
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313 views
Do magnetics connectors exist?
Conventional connectors, where the plug and socket have metal parts which touch, suffer from the following problems:
Limited mating cycles or expensive plating.
Impedance mismatch (relevant for high ...
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1answer
206 views
Building a coil for galvo motor
I'm building myown galvo motors and for that I need some coils that I'll have to build myself to fit into the dimensions I need.
Is there any technique for winding the wire or is it just straight ...
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82 views
Two RJ45s one PHY
Is it possible connecting two RJ45s to a one port ethernet magnetics? If yes, Does it require just turns ratio adjustment or other issues have to be taken into account?
Thanks!
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2answers
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How to check whether a component can work in strong magnetic fields?
I want to design my PCB to operate nicely even when we place it next to a neodymium magnet. How to check whether my component can work in such condition without shielding?
Edit: I haven't face any ...
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437 views
How big a magnet do I need to wipe my portable HDD?
According to this article, I need a really big magnet to wipe the data off my HDD. Thing is, I don't know how strong a "laboratory degausser" is, so I'll ask it in my own terms: I have a pair of ...
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3answers
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How is the state of a bit position on a hard drive measured?
Firstly, I am not the EE type, but I do have a petty good foundation on physics work on a pretty low level. I was wondering what mechanism it is that measures the magnetic indentation on hard drive ...
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2answers
207 views
Sending data over a magnetic field
I need to find a way to trigger this Hall Effect Sensor with a non-permanent magnet. Does anyone know if an inductor's magnetic field would be strong enough? Or am I going to have to build an ...
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2answers
884 views
Controlling an electromagnet with Arduino
I'm just starting up with electronics and looking to control an electromagnet with the Arduino. I'm wondering what hardware setup will make the most sense to use to turn the electromagnet on and off ...
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1answer
429 views
Which type of Ethernet magnetics should I choose for PoE?
I'm trying to find a suitable PoE MagJack for use with my Phy, KSZ8051MNL. The problem is that I can't find one with the same suggested magnetics topology. The closest one I can find has one extra ...
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2answers
281 views
Discrete Ethernet magnetics
Rather than using an Ethernet magnetics component, is it possible / reasonable to simply use individual isolating transformers?
Inside the magnetics component, it's clearly made up of individual ...
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1answer
97 views
Fine-grained sensing of distance between two permanent magnets
(disclaimer: bit of an electronics newbie here)
I have a bunch of little magnet ball-bearings that I was playing around with the other day. I formed them into a strand, then fixed both ends leaving ...
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3answers
366 views
For remoting 1000Base-T ethernet connector, is it better to remote PHY from magnetics or magnetics from connector?
I'm in need of remoting the gigabit ethernet connector from the main board to a back end board that has all the other connectors. I plan on doing this with a high speed board to board connector ...
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2answers
285 views
Using the audio input port as a voltmeter
I'm a physics undergraduate currently studying electromagnetism. I have no experience at all with playing with electronics. I'm trying to see the effect of a changing magnetic field on a closed ...
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1answer
54 views
generic term for inductors/capacitors/transformers for power-handling applications
Can anyone think of a generic term to cover capacitors and magnetics for power-handling applications? (is there one?)
I want to distinguish from power semiconductors and signal-level ...
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2answers
1k views
Magnetometer dynamic calibration
I am working on a Magnetometer AK8975 being a part of an IMU. Which seems to be very tricky for me. This chip gives a 3D vector as output describing earth's magnetic field at any place on earth or ...
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1answer
341 views
Do diamagnetic material exhibit induction?
Silly question perhaps, but do metals with the property of diamagnetism also exhibit inductance? Would a fluctuating magnetic field induce a current in a diamagnetic metal?
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1answer
2k views
Ethernet: how important is the magnetics topology?
I have some Ethernet issues with a set of boards (6/10 are bad). They're possibly just assembly house mistakes... but I'm very concerned about my magnetics jack.
I could have sworn I saw a example ...
