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.

Filter by
Sorted by
Tagged with
0
votes
0answers
10 views

Digital measurement of dissipation factor for HV transformers

I am reading some documents on how to calculate and measure the dissipation factor tor tan delta by using the digital measurement and here is the link. After reading first what is the dissipation ...
0
votes
1answer
101 views

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 ...
-5
votes
2answers
126 views

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 ...
1
vote
1answer
129 views

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 ...
2
votes
3answers
76 views

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 ...
0
votes
1answer
62 views

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 ...
2
votes
2answers
55 views

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 ...
12
votes
4answers
2k views

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 ...
0
votes
1answer
45 views

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 ...
0
votes
1answer
71 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 ...
0
votes
0answers
129 views

Transformer Welfare

I know this circuit is dangerous, but i made it anyway (probably a mistake)-https://www.instructables.com/id/Variable-voltage-ignition-coil-power-supply/ In my circuit, I used a small ignition coil ...
5
votes
2answers
1k views

1kV DC Circuit - Insulation on ground wire?

If I have a 1kV DC circuit, does the ground wire need to be rated for the full 1000V? The circuit is pretty simple, two wires from a power supply to a resistive load.
0
votes
3answers
79 views

Safety and isolation transformers

What safety measures can be taken when using a 1:1 isolation transformer in order to avoid electric shock even if someone touches both ends of the secondary? Would an insulation monitoring device be ...
0
votes
1answer
77 views

Is Mica non-conductive?

Are mica flakes like ones found in makeup and body lotions completely non conductive and should I be worried if it gets inside the components of my computer? Or should I be more concerned about ...
10
votes
3answers
893 views

Is kapton suitable for use as high voltage insulation?

I need to solder together some wires which will eventually run at about five kV, and I'm trying to figure out the best way to insulate the exposed leads. Heat shrink (my usual go-to) is apparently ...
1
vote
3answers
71 views

Why is conduit for 120V building power metallic?

I saw wire conduit being installed in a building, and it was metallic. Wouldn't you want to use an insulating material instead? What if the live wire sheath started to fail? It would short to the ...
2
votes
1answer
74 views

Why does wire insulation have a working voltage and peak voltage?

I understand the concept of a wire having a working voltage and a peak voltage. My question is, physically why is this? What is happening? I was under the impression insulators had a dielectric ...
1
vote
1answer
62 views

Electrical insulation resistance of TO-220 package with SIL pad and plastic shoulder washer?

What would a ballpark insulation voltage (HI-POT) rating be for a TO-220 package (with a "hot" tab) mounted to a grounded heat-sink with SIL pad and shoulder washer? I am not seeing much ...
4
votes
2answers
112 views

Capacitor outer case insulation

Im designing a high voltage circuit and I have a trace at a different potential than the capacitor it's running underneath. My question has two parts, in general, what is the insulation around ...
2
votes
0answers
52 views

Grounding a device with double insulation prohibited?

There are Class I and Class II electrical devices. Class I devices need to have live parts grounded and Class II have double insulation. Why grounding of class II devices is prohibited? I mean, we can ...
2
votes
1answer
175 views

Transformer Insulation - High Voltage can Jump Through Ferrite Core?

First of all, I really searched the topic on both EE.SE and Internet but could find nothing. If this is asked before, please forgive me. As I stated here earlier, I was working on an HV amplifier. ...
3
votes
3answers
75 views

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 ...
0
votes
2answers
58 views

Proximity of Insulated Wire

I want to sell an electrical product with an earthed, metallic enclosure for commercial use in Europe. The wiring inside the product is pretty tight. Are there any laws that prevent me from having ...
0
votes
1answer
66 views

How to evaluate equivalent insulation resistance of two cables?

My guess was that the equivalent insulation resistance of two cables in parallel is same as the equivalent resistance of two resistances in parallel. But instead it is the sum of the two insulation ...
0
votes
1answer
61 views

What is the voltage between each turn in a transformer winding

From a perspective of insulation, how much voltage between each individual turn in a transformer? Example from picture above, the primary winding have 16 turns. Let`s say 800VDC is applied between + ...
4
votes
1answer
785 views

What is this translucent heat-resistant insulation?

On the picture from this question, what is the translucent insulation on the transformer center-tap made from? It looks like polyethylene, but it obviously isn't because PE would melt at soldering ...
4
votes
3answers
247 views

Coloured coating within CRT

I have noticed that a lot of CRTs have a coloured coating inside of them that would appear to have practical purpose other than maybe protecting the aquadag. Paints and plastics tend to be avoided in ...
2
votes
0answers
190 views

How to insulate a high voltage PCB trace?

I am making a PCB with a HV power supply module. Namely the C9619 module from Hamamatsu. The module produces up to 2 mA and 4 W of power so the heat won't be a problem The module can produce up to ...
2
votes
1answer
119 views

Name of fabric insulator found inside motors

What is the name of the fabric sleeve insulator used for components (typically fuses) and solder joints found inside motor windings? Can regular heat shrink tubing be used as a substitute? Image by ...
5
votes
2answers
2k views

How to solder Christmas lights insulated wire?

I want to fix Christmas lights like these, whose wires got cut near the batteries. The LEDs near the batteries still work. I tried touching the wires from the two parts and I was surprised that the ...
1
vote
3answers
118 views

Electrical isolation problems when routing between pads of SMT resistors/caps

According to answers to this previous question, routing traces between the pads of SMD caps/resistors, as shown in the picture, is not dangerous as long as trace to pad clearances are obeyed and the ...
1
vote
2answers
567 views

DC Motor Winding Insulation Material

As I understand it, the field coils and armature windings in a DC motor are insulated and this insulation can 'burn off' if the motor overheats, causing a short circuit to develop. What is the ...
4
votes
1answer
172 views

How are electric under blankets fail safe?

Electric under blankets are mains powered and yet you lie on them. 240V in the UK. They appear to effectively be a single resistive heating element. Clearly they're not earthed as that would be ...
0
votes
1answer
93 views

How to prevent noninsulated wires close together during manual wiring a PCB?

Actually I have two problems, but this one is most annoying: I have like 10 wires I want to solder to the pins of a pin header (2.54 mm distance apart). Initially I kept like 5 mm of the end of each ...
1
vote
2answers
208 views

Meggering Three Phase Motor (Phase-GND, Phase-Neutral, GND-Neutral)

When meggering a three phase motor, could someone please help me understand the values we would expect to see for a motor with no insulation or ground faults. From my understanding: Phase-GND: ...
14
votes
1answer
1k views

Are there disadvantages of heat shrink tubing with higher shrink ratios?

Heat shrink tubing comes in various shrink ratios. The most common of which is 2:1, but there are also 3:1, 4:1 and higher. Assuming cost is the same, are there any disadvantages or consideration ...
2
votes
4answers
143 views

Proper insulation of wires connecting to the submersible pump (5V)

I'm building a simple plant watering station, which uses a relay-controlled submersible water pump (this one). The intent is to submerge the pump into a large enough water container to avoid frequent ...
0
votes
7answers
187 views

How to strip pieces of insulation in a wire?

I would like to strip some insulation from a wire (like shown in the image below, the green area should be only the metal inside, no insulation). I was wondering how I could possibly do this. Cutting ...
5
votes
1answer
273 views

Insulation Voltage of Aluminum PCB - With and Without Electronic Components

We are working on a product that contains an LED module consists of 66 LEDs (33s x 2p - 100VDC load voltage). We'll use aluminum PCB due to the thermal requirements but the customer requirement ...
1
vote
1answer
103 views

Insulating from static electricity

I am happy to announce that my pocket extra-strong static electricity generator project is now complete and works well. However there is one problem, I am often getting zapped severely (to the extent ...
0
votes
1answer
247 views

the volt time constant of a pulse transformer

I am looking for a transformer to use with a RS485 driver, but I don't know on what criteria I am to pay more attention: Insulation Voltage or Volt-time constant. Can someone explain me if the volt-...
0
votes
1answer
53 views

Is thermally conductive epoxy needed if long settling time is acceptable?

I'm using SMD based analog temperature measuremet ICs (a version of the old TMP36). It will be mounted on a tiny and thin (.5mm) PCB I've cut to hold the IC and a few mfgr recommended parts and a 3 ...
1
vote
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 ...
3
votes
3answers
400 views

What material(s) are used in IC's as insulating layers between metal layers?

This question and the answers hits close to the topic. One picture shows it as SOD. Silicon-oxide dielectric? I'm aware that around/within the transistor, silicon oxide is grown for insulation where ...
5
votes
2answers
2k 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 ...
0
votes
1answer
163 views

Megohmmeter, Insulation tester, megger

Can anyone please explain how does megohmmeter (insulation tester) work. Here is what I don't I don't understand: These little tester can produce e.g. 1000V, how is that done? What are the internals ...
4
votes
3answers
700 views

How to safely insulate the Power PCB of a display computer monitor?

CONTEXT The other day I was checking the heat coming off an aluminium heatsink on the power PCB of an eizo EV line led display monitor. It was okay, not too hot, just warm and tad bit hot. When I ...
3
votes
1answer
168 views

Isolation for TO-247 Leads at High Voltage (1000V)

Regarding the fairly new High Voltage SiCFET Devices with operating voltages of 1200V+ in leaded TO-247 packages (or variants thereof): How to isolate the Gate-, Drain- and Source- leads (and ...
2
votes
2answers
61 views

Insulation resistance tester: orders of magnitude difference in measurement depending on connection polarity

https://youtu.be/eGjd7HoYyz8?t=115 The man on the video is measuring a transformer's insulation resistance, the resistance measurements are very different depending on how the meter is connected: ...
1
vote
1answer
135 views

Will copper wire with a non-tarnishing coating be insulated?

I need to make a coil to test voltage created by flux for a project, but bought the wrong grade of wire. Will the non-tarnishing coating act as a good enough insulator for voltages in the millivolts? ...