Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [thermal-cutoff]

29 questions
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Why do we assume VGS0 for a mosfet in cuttoff and Vce>0 for a BJT in cutoff?

The devices below are both n polarity devices, the BJT is a NPN and the MOSFET is a NMOS. For the BJT in cut-off, why do we have to assume \$V_{ce}>0\$? For the MOSFET in cut-off, why do we have to assume \$V_{GS}…
pyler
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6
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4 answers

Why not include a thermal fuse in electrical outlets?

I have found myself reading reports of fires lately, including some that started due to high-resistance connections in electrical outlets and switches. A load on a high-resistance connection can generate enough local heat to ignite building…
Stephen Collings
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5
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2 answers

Thermal relief style X or +?

Are there any differences between a thermal relief in a 'X' shape for a '+' shape? I am using Altium and the software has both styles for selection.
mFeinstein
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4
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Do Thermal Cutoff switches exist for temperatures below 50 C?

I have been trying to find some passive thermal cutoff switches for a project, but it seems that all of them are for 65 degrees C and up. Is there another name for lower temperature TCOs? Any help in finding these would be very much appreciated.
Xantham
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2
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1 answer

Options for a simple over-temperature cut-off?

I am designing a heater circuit that will be used in a product to be produced in small to medium quantities (hundreds to thousands of units, not tens of thousands). This heater will be PWM controlled to maintain a set temperature in the heated…
Matt B
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Determining values when designing with thermal fuses; calculating influence of location/proximity to heat source & properties of protective coverings

The root question: Are there any best practice rules or guidelines for spec'ing out a system with a non-resettable thermal fuse? What criteria is used to determine what rating fuse is needed? I'm primarily talking about the fuses you find in most…
JCReardon
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I need to make a makeshift thermocouple given limited resources in the third world

I'm living in a part of the world where scrap electronics are hard to come by. Recycling these are big money in the impoverished SEA region I'm living in. I have a Fluke 289 with a type K thermocouple that is reasonably precise. I really don't want…
Aaron Butkovich
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High voltage power thermal fuse for DC

I am looking for ways to break a high voltage DC power line when an overheating scenario occurs. Preferably I would like to do so using a thermal fuse but can’t find any thermal fuses rated for high power and voltage DC. Does this not exist? Is it…
LukasL
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Name of this crimp connector?

What is the name of this crimp connector? It looks like a spade connector (female) with a missing tail. In the picture, it used to attach a thermal fuse. Does it require a special tool to install? Can you make your own by repurposing a spade…
Jet Blue
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Using a thermal fuse in a PCB terminal block?

(This is related to question How to solder a 70 °C (158 °F) thermofuse). Would it be a good idea to use a temperature/thermal fuse inside a terminal block like the picture below. I see only benefits: No problem destroying the fuse because of…
Michel Keijzers
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Thermally protecting a varistor

I am designing a circuit that has a nominal 24VAC input. This circuit is protected by a 4A Fast-Acting fuse. I would also like to insert a transient voltage surge protection. For achieving that, I am willing to add a 26VAC varistor between the input…
gstorto
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Does the color band on a thermal fuse indicate temperature?

I have a thermal fuse that is blown (open circuit.) Any textual markings it might have had are worn away, but I'm wondering if the yellow color on the one end is significant. In looking for possible replacements, I've seen yellow, black, tan, etc.,…
Dave H.
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Does the thermostat cause arcing?

I am planning use to resettable thermostat switch in my circuit. I will use it to turn off the optocoupler input. With 5 volt, current is 5-10 mA in optocoupler LED. But I'm worried that an electric arc might occur between the contacts. Electric arc…
johny adv
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Thermal Faliure of thermal overload protected ICs

I have encountered a number of instances now where ICs that supposedly include "thermal overload protection" will still heat up until they fry. Examples: LM338,LM2576. These devices datasheets provide little details of the thermal limiting…
Brandon Hill
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Constant Power Micro Load

I am trying to make a circuit that slowly discharges a multi cell lithium battery to storage voltage. I already have a comparator circuit that can turn on or off discharging. I want to support 2s to 6s batteries so we are talking about voltages…
Y. Shrestha
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