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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How does the tester screwdriver work?
How does the tester screwdriver work? If I put the tester screwdriver inside the "hot wire" of an electrical socket, it lits up if I press my finger against the metal cap on top of the screwdriver. ...
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Voltage required for a spark plug - dielectric constant of air
The dielectric constant of air is approximately 3 kV/mm. The typical space between car spark plugs is between 0.6 and 1.8 mm. By multiplying those numbers in mm by the dielectric constant of air, we ...
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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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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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Measuring currents between 100pA to 100uA
I want to measure absortion/resorbtion currents of dielectric when applying 1000V, 1500V, 2000V.
I have made a small currents measuring device using a LOG114:
I use : LOG114 with 1uA reference ...
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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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PCB material with high dielectric constant
Typical PCBs have a dielectric with a low constant \$\varepsilon_r\$. I'm studying the effect the electrical fields on dielectrics and as an experiment would like to test PCBs with a very high ...
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Can I calculate minimum rise time of a transmission line if I know the length and the loss tangent?
Overview: I am trying to work out if it's possible to transmit my 1.2Gbps MIPI data down a 600mm long flexible PCB strip. Assuming I have the impedance correct, will the signal still be degraded by ...
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How does selecting a higher permittivity substrate in patch antenna reduce its size?
By selecting a higher permittivity substrate do we reduce the height of the antenna or we reduce the length of the patch antenna? We cannot reduce the length of the antenna as it is dependent on the ...
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What dielectric liquids can be used as coolants?
I've seen some interesting videos of people putting their computers in containers with sunflower oil, where they continue to work normal.
Are there any other dielectric liquids that can be used to ...
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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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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 a ...
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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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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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How do internal capacitor stud finders work?
I don't understand how a non-magnetic object like wood can be detected using a stud finder.
For instance, stud finders find wood from the dielectric constant, but I don't understand the principle.
The ...
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