Questions tagged [conductivity]

Electrical conductivity or specific conductance is the reciprocal of electrical resistivity

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3answers
712 views

Which is a better conductor, a very thick rubber wire or a very thin copper wire?

I read somewhere that very thick wires are generally better conductors than very thin ones. Is this true? If yes, then would a very thick rubber wire be a better conductor than a very thin copper wire?...
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2answers
62 views

If my circuit is electrically isolated, do i have to worry about a polarizing effect on my sensor's output?

If I am making a conductivity sensor one of the things it need to watch out for is polarizing the water. easiest way to do this is have the output output signal of the sensor have a +/-0.2V square ...
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2answers
1k views

Why is current rating for multicore cable lower than single core with the same cross section?

As per this resource, a single core 10 AWG (5.3 mm2) copper cable is rated for up to 52 amps, while the same cross section cable of 43 cores and more is only allowed to carry up to 15 amps. Why is ...
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1answer
151 views

Why can my body conduct electricity from a 9 volt battery?

I've created a scenario represented identically in the attached image . My question is this: When I connect Jumper 1 to my left hand and Jumper 2 to my right, the LED turns on very faintly but I feel ...
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0answers
52 views

EC Sensor (Analysing the Circuit)

I'm doing an electrical conductivity sensor; my goal is to build a water monitoring device. After analysis I decided to build my own circuit and make some improvements to other designs. An EC sensor ...
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1answer
33 views

Units of Conductance

I'm trying to understand how conductance that is measured in Siemens is equal to Amperes/Volt. The SI units of Siemens is given to be in $$ kg^{-1}m^{-2}s^3A^2 $$ (link). I am not sure how this is ...
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4answers
9k views

I've become an electrical conductor for my headphones… but how?

So I have a pair of Bose noise-cancellation headphones that I plug into my keyboard every night to charge them (via my keyboard's USB port). My keyboard happens to be a metallic Apple keyboard. You ...
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1answer
34 views

Conductivity formula for Metals

Is there any expression for the direct change in conductivity of metals with temperature ? I am aware of change in resistivity with temperature.
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1answer
112 views

Prevent small signal with noise

I am designing a Conductivity Meter by using Arduino. I used ad9850 to generate a sin wave with 1khz and peak to peak 20mV. but there is a bit of noise with my output Signal and after the voltage ...
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3answers
52 views

Contact pressure vs contact area

I'm learning to weld. I've realised my earth clamp is limited. The spring is weak and its contact area is small as it's tooth shaped. Researching better clamps, I see clamps which have threaded bolts ...
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2answers
100 views

insulated wire giving shock

I'm having some problems at my new girlfriend's house. There was a extension cord that was giving shock and I changed to another. This one wasn't giving shock, but when I test it with that screwdriver ...
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3answers
87 views

Is a 5V DC Voltage @ 30mA applied, applied to water, unsafe?

As my question states, I have 5V DC, with an input current of 30mA, being applied across two exposed metal electrodes which are inserted into water. I am trying to measure the conductivity of water ...
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2answers
162 views

What is the principal of Inductive Conductivity sensor?

What is the principal of Inductive Conductivity sensor which uses two coupled coils to estimate conductivity? Image Source I understand that the eddy current losses changes with the conductivity, ...
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2answers
198 views

using sine or square wave to obtain conductivity of solution?

I see for designing a conductivity meter, Some Designer use square waves, as excitation to obtain conductivity and some others use sine waves for this work in their design, which wave do this job ...
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7answers
2k views

Is there any difference between transferring DC over one 36 mm² wire or six 6 mm² wires?

I am designing an off-grid DIY solar power site where the distance between the solar panels and inverter is going to be several dozen meters, so I would prefer to put a thicker wire to minimize losses....
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1answer
2k views

Apple devices - “Vibrating feel” when charging [duplicate]

I am absolutely not experienced when it comes to electrical stuff at all which is why I hope you can help me out on this one because I am a bit worried right now. I own a bunch of Apple devices and ...
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2answers
1k views

How is clearance affected by altitude (air pressure)?

Let's say you have a high-voltage circuit (or any voltage really) and you want to provide appropriate clearance distance for the PCB, connector pins, etc. (Above image from link) There are standards ...
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1answer
745 views

Dependency of Conductivity on Temperature of Extrinsic Semiconductor

For an Extrinsic semiconductor ,how can we proof the following dependency of Conductivity on Temperature as shown in fig.: My Thoughts: At \$ 0K \$ there is no energy available , hence no ...
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6answers
2k views

What is the ampacity of 14 gauge silver wire?

There is no information I can find (charts/specifications) that gives the ampacity for single core silver wire. But I know this can be calculated, I've found this property list for silver from a [...
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4answers
106 views

How to sense the pull on a metal wire

I'm building a small interactive exhibition display for a museum. The showcased artifacts are protected against theft with a metal security recoiler like this: If a visitor picks up one of the ...
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1answer
591 views

Covering electronic device with plastic film wrap

I hope someone can help here with an electronics issue I have. I am currently shipping an electronics device, an audio reel to reel to be exact. It was suggested that I wrap it in plastic film wrap, ...
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1answer
74 views

Are there any transparent photoconductors? [closed]

Are there any transparent photoconductors? If so, can I know the timeframes of some examples of them where they reach full conductivity? I need one that reaches full(or approximately full) ...
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2answers
3k views

How to design drone power tether system? (high power with ultra light cable)

There are drones that are powered with power tether from the ground station, and such drones can be airborne 24/7, not only 20 minutes when using batteries. I'm very interested to reverse-engineer ...
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2answers
236 views

Will any type of solder bond to any non-conductive material?

Are there materials which solder will physically bond to but itself is not electrically conductive?
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2answers
155 views

How can I make contact with the material if soldering is not possible?

Sorry for the title, I have problems putting it to words in English. I ordered some small and cheap Chinese solar panels. I thought it was fun to tinker with them and learn about electricity. After ...
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1answer
122 views

Can a textile fiber cause an electrical short?

Let's say you are cleaning some USB ports/plugs with chenille pipe cleaners moistened with alcohol. As you can see from the image of a USB port below, the raised wire contacts inside the port could ...
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2answers
2k views

Water leak detection sensor and circuit

I am planing to build a ROV for underwater use and at this point I am concidering to have some water leak detection system for the electronics enclosure that has to withstand underwater pressures up ...
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4answers
477 views

Conductivity sensor AC frequency

I'm trying to figure out how to determine what frequency an electrodeless conductivity sensor needs for accurate measurement. An inductive sensor consists of two wire-wound metal toroids encased in a ...
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5answers
699 views

Measuring water level inside a drinking glass

Background: I am creating an automatic tea brewing machine using an Arduino and an electric water kettle from Amazon. My family and I drink lots of tea and we have many different sizes of glasses. I ...
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1answer
53 views

Wireless RF wetness detecting alarm design

I am working on a project to trigger an alarm wirelessly using RF when wetness is detected. I'm using conductive threads to detect the wetness in a material through the principle of conductivity and ...
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1answer
241 views

Admittance calculation of a circuit

I am measuring the admittance of a circuit, by switching a load off and on at different loads. The admittance value I got from the measured voltage drop and current flowing through my circuit. The ...
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2answers
3k views

Does doping always increase the conductivity of a semiconductor?

The conductivity of a semiconductor is given as (if extrinsic): \$\sigma = qnu_e + qpu_h\$ where \$\sigma\$ is the conductivity, \$u_e\$ and \$u_h\$ are the electron and hole mobilities. But does ...
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3answers
3k views

Why is gold preferred over silver for bond wire?

Silver is a better conductor than gold and in Integrated Circuit package where exposure to air should not be a concern Gold is used. Any particular advantage of using Gold over Silver?
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1answer
711 views

Water conductivity measurements/ESP8266 - getting strange results

Hope this is the correct forum and thanks in advance for reading this. Summary: I'm working on EC (electric conductivity) measurements using a capacitor and the pins of an ESP8266 microprocessor to ...
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1answer
90 views

Unknown Ψ variable in JFET's drain current equation

This question considers unipolar transistor, that is JFET. I really didn't find any other formula than this one which applies only for linear/ohmic/triode region of JFET U/I characteristic. What is ...
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1answer
180 views

Unipolar transistor's transconductance/admittance

Unipolar transistor basic variable transconductance is commonly marked by: It is commonly used in calculations where we need drain current, Ugs, rds(on), and similar. I have also seen many equations ...
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2answers
564 views

does a broken or blown ac adapter conduct electricity? [closed]

I had this question in my mind for many days. The main question came to my mind from times ago when I was working on some electronic devices and at that time I had an ac adapter that it had some ...
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1answer
75 views

Computing the electric potential generated by a current density across media with different conductivities

Model: a right cylinder composed three layers of conductive media. The is a disk of unit charge density in the center of the cylinder. The disk radius is equal to the cylinder radius. The outer layers ...
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1answer
58 views

Why do you need a conductive layer with conductivity of \$~10^4\$ S/cm in a capacitance touchscreen?

ITO has has conductivity of \$~10^4\$ S/cm. A capacitive touchscreen measures the change in capacitance or electric field.  1) Why do you need a conductive layer in a capacitance touchscreen in the ...
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0answers
45 views

Unusual informations of PN-diode

There are several variables like: concentration of electron deficiencies/holes or electrons (n,p) in p/n-type of semiconductor, concentration of donor or acceptor atoms (Nd,Na) in doped semiconductors,...
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1answer
104 views

Conductivity monitoring to detect integrity loss of glass coating of steel

I have an application where the integrity of the glass lining of a glass coated steel vessel needs to be monitored. In theory, once the integrity is lost anywhere there ought to be contact between ...
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1answer
264 views

Electron flow through the semiconductor crystal

Talking about doped semiconductors: Atoms outer shell extends and overlaps with another ones outer shell (the conduction band), right? So when electrical field is applied to a semiconductor bar (lets ...
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1answer
36 views

Difference in conductivities of metals and semiconductors based on quantum theory

According to Fermi-Dirac statistics, in a metal, only certain number of valence electrons take part in conduction when they acquire an energy equivalent to KT for some temperature. Now my questions is:...
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1answer
2k views

Why don't we get electrocuted when touching a pot sitting on an induction cooker

As the title says, why does that not happen. As far as my understanding goes, an induction cooker is a coil of conductive wire through which AC is pumped. This generates an oscillating magnetic field ...
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1answer
62 views

Is there an electronic pre-treatment spray for long life reliability in connectors?

Is there a good spray or paint-on treatment that I can apply to small electronic connectors before connecting them, that will help them maintain a good connection over long spans of time? I am ...
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2answers
587 views

Copper wire thickness

What diameter copper wire (single core, not isolated, open air) is needed to safely conduct 120A current from 22.2V battery to a load on 30cm distance? Of course I searched on the Internet and there ...
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4answers
84 views

Help me understand dielectrics

So, they're insulators or poor/non-conductors of electricity. Yet somehow they are also capable of holding and/or transmitting an electrical charge. Does that not seem like a crazy paradox, ...
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1answer
26 views

Testing changing sheet resistance with impurities

I have a chemical film, and I'm trying to detect the presence of impurities on the film. They should change the resistance. Assuming it does, how do I measure it? I believe the four point probe method ...
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1answer
8k views

How to calculate a cell constant of conductivity probe

I'm trying to design a 4 Pole probe to measure electrical conductivity and I having some doubts about the theoretical calculation of its cell constant. I know the formula, K(cell constant)=L(Distance)...
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1answer
197 views

Typical resistances of jumper wire and silver foil

What is the typical resistances of the following or how can I go about calculating this approximately? 1) Typical jumper wires used in prototyping with breadboards 2) a silver foil with dimensions ...