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Questions tagged [dielectric]

A dielectric is an insulator that can be polarized by applying an electric field. A common example is the use of a dielectric within a capacitor between the metallic plates to increase the surface charge.

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1answer
85 views

How come distilled water hasn't replaced transformer oil as a high voltage insulator?

I've noticed that distilled water has an extremely high dielectric straight (65-70 MV/m). With that considered, how come it isn't used in the place of transformer oil for 10-20 kV applications where ...
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47 views

PCB Layer Stack Dielectric Constant Math

I have a question reference PCB layer stack and the adding multiple dielectric constants together. The image and description below should help clarify the question: The differential pair will be ...
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1answer
64 views

What are the “poles” of a signal (after it's reflected perhaps)

I desire to learn about "estimating the poles of a resonant signal", specifically the complex natural resonance of objects. However, I don't know what "poles" are. What would you suggest I look up ...
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69 views

HF characteristics of Liquid Electrical Tape

Some self-wound toroid inductors from a HF-radio kit are sitting a bit too loose on their PCB for my liking; they stand upright and are only held in place by the thin enamel-coated inductor wire that ...
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1answer
59 views

How can the dielectric constant of water be so high but water on electric devices can cause a short circuit? [closed]

Is it only the fact that pure water has a high dielectric constant and non-pure water i.e. the water that usually causes a short circuit is contaminated and it's the contamination mixture in the water ...
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87 views

C0G vs polypropylene capacitors in signal filtering

Can anybody give me a comprehensive pros and cons list or explanation about the differences between C0G (NP0) ceramic and polypropylene capacitors? I would like to use them in signal filtering and ...
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52 views

Grounding polycarbonate or Plexiglas

If a record turntable's base is made from a 2" think piece of acrylic (for instance polycarbonate or Plexiglas) can it be successfully grounded to eliminate any static charge that it would build up in ...
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26 views

termination of a parallel wire differential transmission line as delay line on variable dielectric constant medium

Well this has quite a long title, lets explain the situation I'm currently working on the design of a sensor to measure the dielectric permittivity of a liquid medium, the idea is to use a ring ...
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23 views

How flux density increases in the dielectric medium?

The above figure shows a polar dielectric medium in an external electric field which is normal to it's surface. From the equation of D(electric flux density) we see that flux density increases but ...
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1answer
23 views

PEC-backed dielectric material

For the paper named "Antenna Miniaturization and Bandwidth Enhancement Using a Reactive Impedance Substrate" the statement "PEC-backed dielectric material", so what is the meaning of this statement? ...
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3answers
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High voltage dielectric breakdown & layering insulators

I’m going to use 230 kV as the reference voltage for the example below; I know if I put a piece of metal too close to a 230 kV source it will breakdown the air and jump to the piece of metal causing ...
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160 views

Capacitance of circular parallel plate capacitors

I've been trying to solve this question for a while now , but I can't seem to get to the written solution. Question : Calculate the capacitance of a parallel capacitor having two identical conductor ...
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1answer
47 views

Dielectric Loss for Constant Impedance

Are dielectric losses the same for two different 50ohm structures that are built in the same dielectric medium? Eg. Two 50ohm Stripline traces in FR4 where one is very skinny with close GND planes, ...
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279 views

What would be the combined dielectric constant of two dielectrics in series?

Let's say we have two parallel conductor plates. In the middle, there is not one but two layers of dielectrics made of different materials. If we know the relative permittivity of each dielectric, how ...
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What lubricant is suitable for switch contact?

I have this expensive DPDT switch (20A 250V 2hp) which the only problem is dirty encumbered inside. The encumbrance is made of carbonized material and some kind of wax and dirty electrical contacts. ...
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1answer
30 views

variation of thickness of dielectric layer for different textile-based capacitive pressure sensors

For my thesis I am working with textile-based capacitive pressure sensors and I am struggling to see how much variation in thickness of the dielectric layer you can have before you have noticeable ...
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1answer
93 views

How far does reforming a capacitor help? Does it have any adverse effect on using such a capacitor on components?

I read a few articles on the internet about reforming capacitors. Does this actually apply only to a capacitor that was stored during a certain period of time or can it be used on any electrolytic ...
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3answers
363 views

Coaxial cable: how is it possible to define a conductance?

I have a coaxial cable with internal conductor of radius r1 and external conductor of radii r2 and r3. The material of the conductors has a conductivity \$\sigma_1\$. Between the conductors there is a ...
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1answer
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What impact, if any, does the solder mask color have on the electrical and mechanical properties of a PCB

At my place of work, we use soldermask colors as a sort of poke-yoke for manufacturing purposes E.g. Technicians know that green pcb goes with green, blue pcb with blue, etc. This has lead to some ... ...
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1answer
46 views

Decide coherent time and fade duration through empirical studies on the channel and relate them to channel modeling

I. Scenario: TX floating in the lossy heterogeneous medium with undetermined positions within a limited region; RX fixed in the air and closed to the boundary of air-lossy medium; Frequency: 500 MHz ...
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2answers
59 views

Suggestions on conductive materials for textile capacitive pressure sensors

I am doing preliminary research for my thesis. The thesis involves textile capacitive pressure sensors. I am trying to find out more about how the type of conductive material used affects the ...
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1answer
118 views

How does glass create an electric field?

I'm reading from Microchip's data sheet regarding their MAXTouch microchip, which details on how to create a touchscreen compatible with their chip, and in discussing the "mechanical stackup" of a ...
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1answer
159 views

Capacitor dielectric: Is X7R a direct upgrade over 2C1?

I'm trying to replace a capacitor with an IECQ-CECC 2C1 Dielectric. The supplier has offered a comparable EIA X7R Dielectric. Viewing this comparison document, they are largely identical. However, the ...
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2answers
95 views

Material with fairly high resistivity, but allows flow of charge

Is there a material with fairly high resistivity (at least semi-conductor level), but also allows the flow of charge through it (and subsequently to the ground)? The flow of charge does not need to be ...
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1answer
53 views

How does same capacitor with different dielectric affects the circuit?

I am working on a project and finalizing 0.1uF capacitor with 50VDC(decoupling). I am finding with different dielectrics. My question is how does two diffrenet capacitor having same capacitance and ...
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3answers
120 views

Capacitor dielectric and current flow [duplicate]

A capacitor has insulating material between plates and this insulting material does not provide any electrical or conducting path between capacitor plates. But still, capacitor allows DC or/and AC ...
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5answers
136 views

Confusion regarding effect of dielectrics on energy stored in a capacitor

If inserting a dielectric has the effect of reducing the magnitude of the electric field in a capacitor (holding all other variables constant), then why is the energy stored in a capacitor directly ...
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1answer
193 views

Use AD5933 evaluation board for impedance calculation 1Khz-100kHz

I recently got the AD5933EBZ evaluation board. After taking a look at the user guide, the AN1252 application note and the datasheet of AD5933 itself, I am trying to measure the capacitance across a ...
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4answers
151 views

What is the correlation between dielectric plates and capacitance? [closed]

A project I'm working on requires a capacitor of 37000 uF and a voltage rating of at least 10kV, but every capacitor I find online can only meet one of these standards and is very expensive, so ...
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3answers
246 views

Electrical generator where a dielectric is pulled out of a capacitor

In physics class I learned that removing the dielectric out of a charged capacitor increases the voltage and therefore the energy stored. Could this effect be used to build a generator? The extra ...
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1answer
120 views

Phased array minimum size

I want to know two things,how big does the phased array needs to be to form proper beam and what is the smallest area the beam can be focused.I learned little bit about lasers and with focal lense,the ...
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1answer
2k views

What is electron trapping

I am reading an article in which they consider a model for charge transport in dielectric. The following figure can summarize the different procedures done in this manner: I am new in the domain ...
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1answer
223 views

Dielectric Transformer Oil

Which commercial oil can i use for isolation of a high voltage transformer+voltage doubler?.The output voltage is about max 60kv.
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54 views

Side effect of dielectric polarization

Sorry for my obvious question, but I am not from the field of electronics and electric engineering. I was reading this article: The first sentence in the introduction says: " All solid ...
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1answer
1k views

Pros and Cons of Types of “Dielectric Grease”

I have come across two different types of dielectric grease. One, the "usual" kind, is a silicone grease that has added insulators. Another, less common, is a hydrocarbon grease, typically ...
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1answer
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Technology “dielectric constant” information

OK, so when working in a technology, say Bipolar, to build a high frequency amplifier, can I trust that the dielectric constant info for the various films contained in the electrical design rules, are ...
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0answers
182 views

Installing (and soldering to) PTFE (teflon) Insulated Terminals

I am doing a condenser microphone board project. Now I need to install two PTFE insulated terminals (these are in the picture) to a board. The holes are a little larger than the bushing of the ...
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4answers
2k views

Confusion in understanding the relation between permittivity and capacitance

The insulating medium between the capacitor plates is called dielectric. This appears in the Coulomb's law: $$F = \frac{q_1 q_2}{4 \pi ɛ r^2}$$ ɛ is the "permittivity" constant which depends on the ...
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2answers
674 views

Understanding surface and volume polarization charges

Can someone please give me an intuition of this formulae? I am unable to visualize the formulae in equation 5.26. Specific question - How does a dielectric when kept in an external electric field ...
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2answers
159 views

question from capacitors

A capacitor of capacitance 1uf withstands maximum voltage 6kv while a capacitor of 2uf withstands maximum voltage 4kv. What maximum voltage will the system of two capacitor withstands if they are ...
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1answer
241 views

Mutually Insulated Circuit

I am reading through a HIPOT / Dielectric Strength requirement that states in no so many words: "withstand damage when 1KVac is applied between all mutually insulated circuits" I search every where ...
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3answers
642 views

Material whose dielectric constant * [dielectric strength]^2 > 20,000,000,000

I'm looking for a material or compound, whose dielectric constant multiplied by the square if its dielectric strength (MV/m) is greater than two billion at temperature from -20C to 100C. It doesn't ...
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1answer
126 views

Can anyone here help me build a capacitor?

Here's the project: I'm building a capacitor by hand to essentially measure the permittivity constant. I am doing so by building a capacitor of known dimensions, setting up an RC circuit and plotting ...
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3answers
477 views

layering high dielectric constant and high dielectric strength materials in a capacitor

I'm trying to get a better understanding of the relationship of dielectric constant (relative permitivity) to dielectric strength (breakdown voltage).I want to know what happens when you layer ...
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1answer
62 views

RF dielectric measurement of a sample

during non contact dielectric measurement of any sample using VNA and patch antennas,should the antenna dielectric be taken into consideration for calculations? i want to use a ultra wide band patch ...
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1answer
151 views

What happens to current if I change dielectric from air to material with Ɛr>1

Electrostatics: One of the job interview question: Plate capacitor, with area of electrodes S, and distance between them d,has air as dielectric. Capacitor is connected to constant voltage source. ...
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1answer
171 views

Unit of permitivity

In electromagnetism, permittivity or absolute permittivity is the measure of resistance that is encountered when forming an electric field in a medium. In SI units, permittivity ε is measured in ...
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1answer
158 views

Adding Slab to a Capacitor

I was solving a question in an Electromagnetics book and need some help: two parallel plates were connected to a 100V battery. The battery was removed and then a slab of dielectric material was placed ...
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4answers
95 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
313 views

How can S11 component measurement circuit be made on a pcb?

I have a material whose dielectric properties need to be measured. I have done literature review on the physics & impedance based methods to determine the dielectric component. It requires S11 ...