Questions tagged [insulation]

An insulation or insulator, is a barrier of non-conductive material around electrical conductors and other circuit-components like resistors, capacitors, IC etc.

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How to distinguish different temperature wire insulations?

Wire insulations have different temperature ratings: 80°C 90°C 105°C 125°C 200°C These ratings can result in different current ratings for the same wire gauge. Are there ways to distinguish ...
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Would an inductor work differently under a different dielectric environment?

I am talking about these common rounded inductors with a metal core that you would find on PCBs. Would the operation be different in, say, mineral oil vs. air? These are two different dielectric ...
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PTC Heating Element Watt and Insulation Film | Hot Melt Glue Gun

Question 1 If two glue guns of 20 watts and 40 watts are receiving direct current from the electric board (no adapter). Then what makes one gun 20 watts and the second one 40 watts. Is it related to ...
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White insulating sheets inside power supply

Does anyone know what this kind of sheet is called? I presume the purpose is for electrical insulation. The one in the picture is found on a fan inside a power supply.
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Insulation monitoring device for electric vehicle

Good day to all! I am planning on designing an electric vehicle architecture from scratch. My main DC bus voltage is 400 V. However, I have got different voltages in my system. I have got a 600/400 V ...
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What Stops the Windings on an Electric motor From Shorting with Each Other?

What stops the windings from shorting with each other? Are the windings insulated when the copper is still not bent, then the insulated copper is bent into the winding shape?
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Landing a Thermocouple on a surface with voltage present

I am connecting multiple K-type TCs (thermocouples) to an electric engine prototype. I have had a problem with the TCs having up to 150 volts on them when the engine is running. I don't know the ...
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Difference between Working Voltage and Isolation Voltage?

I am building a board to collect data from a 2000V system. The board is going to be powered from a USB port on a laptop and data collected directly into the laptop. I am looking at Isolated 5Vto5V ...
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Electric shock through thick rubber tube filled with coolant and carrying a high voltage wire

I have two Litz wires coming out of a coil. The coil is driven with short pulses of 20 kHz sinosoidal voltage with a peak of 1.4kV. Each Litz wire is insulated by 3 thin layers of mylar sheets in ...
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How much voltage can one layer of a common black electrical tape block? [duplicate]

Wikipedia says just "Low voltage, phase B". The tape I bought has no specification about such property on the package. About how much voltage can one layer of such tape block? If one layer ...
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Is asymmetric insulation resistance a sign of AC appliance failure?

I tracked down an AC appliance (a dishwasher) which started tripping my home current circuit breaker (RCD). I happen to have a professional insulation resistance meter and I was able to measure about ...
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How do you pass Insulation Testing when your load is low impedance?

This is probably a silly question but I read that for class I equipment I need to perform insulation resistance tests and it must be under 1 megaohm. My understanding is that one of these tests ...
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Why is insulation resistance is bad when absorption Ratio ≈ 1 and insulation resistance is good when absorption Ratio >1.25 or 1.3?

i will do absorption Ratio (AR) test for transformers in my job,and i know how to calculate the absorption Ratio AR=\$ \frac{R_{60}}{R_{30}}\$ \$ R_{60}\$=Insulation Resistance after 60 second test \$ ...
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What is the standard PVD coating for electrical insulation purposes?

I want to insulate some copper parts with a thin coating. I am interested in a physical vapor deposition (PVD) process, but I’m not sure if PVD is suitable for the deposition of an electrically ...
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Insulation and losses In transmission line

Why do we consider only P=V.I In AC transmission while designing the insulation of transmission line not the equation P=V^2/Z and consider this equation in determine the insulation in DC transmission ...
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Electric-grade gel / silicone to provide physical protection for circuit boards from damage

Not looking for a brand or product (unless allowed to ask) just the generic name for electric-grade gel / silicone that can be poured on the circuit board or embed the circuit-board in it. It would ...
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What's the right replacement for vintage "glass cloth insulation" that transfers heat in Variac?

I ripped apart a broken 1950s-era Variac autotransformer to diagnose an internal short in the core, and found a layer of gooey insulating fabric mat between the coil/taps and the mounting plate: The ...
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Trying to understand practical applications for bonded metal laminations & insulated epoxy coating [closed]

I am trying to better understand practical applications for bonded metal laminations and insulated epoxy coating. I started a new job at a company that does this and I am so lost. Any insight would be ...
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Strain gauge installation tester vs. insulation tester

An insulation tester (or a Megaohmtester) costs in the range of 500-1k USD and can measure up to G-Ohm and more in resistance. Even a big brand tester like Fluke 1587 costs under 1k. Not saying they ...
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Delayed insulation failure of DC barrel jack

Recently I had to replace a male DC barrel jack that connected a string of LEDs to a driver. Unconnected, I measured 100 VDC out of the driver. The male jack I salvaged from an old 12 VDC power ...
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Is solder mask a valid electrical insulator?

I had some PCBs manufactured prior to ordering all of my components :-( It turns out that the surface mounted 1W LEDs I'm going to use have the heat slug connected internally to the LED's +ve terminal....
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Estimating VAC rating from VDC rating

I have encountered several terminals, sockets, cables, and similar components which are rated in either DC or AC voltage, but not both. I sometimes want to use an AC rated part with DC or vice versa. ...
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How would you apply high voltage on a piece of dielectric making sure breakdown does not occur?

Say you have a piece of dielectric with a breakdown electric field, BDE. For some experimental requirement you have to apply an electric field, E > BDE, across the piece of dielectric without ...
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Distribution of charges in an electrostatic study

I have a question concerning the capacitive coupling between two conductors. The capacitance C between the two is only a function of the diameter of the 2 studied conductors, the insulation thickness ...
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Diagnosing voltage reading on battery pack. Possible Insulation leakage?

With reference to this question I asked the other day: How can I measure a voltage between two conductive surfaces that are completely isolated? There was a good answer there so I didn't want to ...
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Which insulating tape and when?

There are quite a few tapes out there, from the plain black electrical tape to different color variations to Scotch 33+, 77, 88 to Kaptons (polyamide), I have also seen some velcro type wraps which ...
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Any electric insulation material that is great heat conductor even 300°C?

Is there any good electric insulation material or tape that is also great heat conductor even 300°C and above. I wish to wrap nichrome wires with this material in creating a water cup heater. Thanks.
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If power lines are properly insulated, why do we see sparks/arcs in videos these days?

I saw a video where power lines touched due to high speed air and created huge arcs. In another video, a person throws a wire in air, it touches a wire and he gets shocked. Also it is said that birds ...
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Thermal compound for Alumina Ceramic Insulator

My main question is there any article or standard that says that Alumina Ceramic Insulator needs any thermal compound or it could be used as it is (in particular for the Transistor/Triac/Thyristor), I ...
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Insulating JST-PH solder points

Shown in the image are the solder points corresponding to the two terminals of a JST-PH connector. (Jumper is there as a size reference). They are way too close for comfort for me, especially with ...
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What is the reason for yellow tape on top of USB mini-B?

I have noticed that occasionally some USB mini-B connectors have what looks like a transparent yellow tape on their top. It might be Kapton tape, but I am not sure. As an example, please see the below ...
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What was used as paint on insulation/conformal coating in the 1950s?

I'm restoring a multimeter from the 1950s and I was wondering what was used as paint-on insulation/conformal coating. It's the yellow/brownish stuff smeared on the screws and leads in the photo. I ...
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Insulate active or neutral?

If you can only insulate active or neutral, which should you choose? Does it matter? Is it important? Is one better than the other?
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Enameled Silver Wire? [closed]

I like to use enameled copper wire where rubbery insulation would be a pain. Recently I embarked on an electronics project with some lights that would look a lot better if the wires were silver color ...
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Insulation pull tabs on PCB to turn on a device for the first time

In some inexpensive electronic products like toys and remotes, there is a small piece of plastic sheet that disconnects a coin cell or button cell. Pulling out this plastic tab turns on the device, by ...
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Heat Resistant Wire Insulation Types

Good afternoon all, For the past several months I have been working on a project at work and the wire I am using is amazing. When I go to solder it into a joint, the insulation does not shrink and ...
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BIL, Dielectric Breakdown, Shrink Wrap, and Safety. Is there a resource for this information?

I am currently working with a system that produces high voltage transients for system testing, and have some cables that need to be made/modified to work with some new equipment. The operating ...
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where to find exact definition of i/p and o/p as used to define insulation resistance for AC DC converter?

Most AC DC converter datasheet use I/p and O/P to define insulation resistance I am looking for the exact definition of these parameters as used in this context ( I know their definition for ...
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What material can I use to insulate NFC tags so they can be placed almost back to back?

I have posters with "Tap me to check in/out of this meeting room" drawn on them. I have NFC Stickers behind each poster to send the user to a specific URL in the application. They are being placed on ...
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Are breakout boards insulated?

I have a prototype board like this, on which I plan to add some solder traces (the black lines). I plan to place a BNO055 on top of this same prototype board and solder it in place without using ...
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Heat-shrink for electrical insulation of a metal hinge

I have a metal door hinge which is part of a trap for a Physics experiment (measuring 'g' by free fall). I want to cover the hinge so that it is electrically insulated. I was thinking of using heat-...
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What is the idea behind "heat shrink tubing"?

I have ordered some tubes that are labelled as "heat shrink tubing". I wanted them to cover non-insulated wires in the montage, to prevent them touching something unwanted by chance, or each other. I ...
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Can I use these wires for AC current? [closed]

I bought these wires on amazon, and I noticed in the description that they are rated for 80 volts, and are specifically not to be used for household 110v/220v wiring. However, this wire is basically ...
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Using Motor Oil as a Transformer Oil Substitute

I need a rather large volume of oil to insulate a few 15 kV wires/coils. Unfortunately, the volume of oil required puts transformer oil outside of my price range. I've noticed that others have ...
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3 answers
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Thin insulation for 400v plates?

In a design of mine, I need to place two plates on top of each other as close as possible. With a 400v potential difference possible between the plates, what is the best material that can be placed in ...
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How good is the Paracord 550 as an electrical insulator?

So following wikipedia the Parachute cord 550 is made from nylon Kernmantle rope, however this site where I sourced the cables from says that it is made of a Polyester sleeve (outer layer) and a core ...
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Double insulation for NTC sensor

I am a bit in trouble with finding a double insulated 10k NTC sensor and I am questioning what double insulation really means. Does double insulation mean, that there are really two different ...
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13 votes
4 answers
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Why in the world would the tab on a TO-220 package have a connection to anything (but GND, if applicable)?

I know this is in some way a different version of the prior question In i.e. a TO-220 package, why is mounting the (pin connected) tab to case safe? But I am not looking for ideas what to do to mount ...
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Is 1.4mm Pad Distance at Optocoupler Pins for 230V/50Hz Mains Detector Enough?

For a project, I use an optocoupler to detect 230V/50Hz AC on a line - if a light switch connected to mains is pressed. For my calculation, I use 240V as a maximum AC voltage. It will limit the ...
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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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