Questions tagged [thermistor]

A device that is used to detect temperature - the word is a portmanteau of thermometer and resistor. The detection mechanism is the measurement of resistance which changes predictably with temperature.

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1answer
29 views

How do I accurately measure the B value of an NTC thermistor?

I'm trying to find a part number for an NTC thermistor being used to monitor the temperature of a rechargeable battery. The thermistor I have has no color markings or numbers to indicate any ...
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50 views

Op amp to supply current to 3 thermistors and an ADC voltage reference input

I have 3 thermistors in parallel that I need to measure. These thermistors will be fast changing - think up to 100C in under 1 second. I want to do this ratiometric measurement, so I want to supply ...
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44 views

Analog differential signaling

I'm a software engineer that sometimes has to deal with some electronics. So I'm by no means an expert... I want to control a BLDC motor and I have added a thermistor to the windings of the motor so ...
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58 views

What is the thermistor sensitivity?

Here it is written: Some references use the negative temperature coefficient (NTC) a to describe the sensitivity of a thermistor alpha = -B/T². and here it is The B constant expresses a degree ...
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37 views

Oversampling, additional bits and a thermistor

Say we have a ten bit ADC (MSP430G2433) and a thermistor. We have the problem that two temperature measurements are too far apart, whilst the temperature has barely changed. So, we take more ...
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51 views

Part number Molex 4 pin wire-to-board connector and 2 pin wire-to-board like Corsair CommanderPro

I'm having a really hard time finding the correct PN for a 4 pin header, used with PWM fans. The header I'm looking for is a 4 pin one, similar to the Molex 47053-1000, but a right angle one. I've ...
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85 views

Anemometer with opamp

This is related to an earlier question of mine, but I have a different follow-up question that I wanted to make a new post for. I'm trying to understand more about how the below circuit works, ...
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General LiPo and Li-ion question regarding NTC

Is it only me or are most of the smallish (1500mAh) LiPo rechargeable batteries don't have the NTC pin (only POS and GND)?
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Finding equation of curve for NTC type thermistor [closed]

I have an NTC thermistor from the KTM 390 engine which I am trying to interface with the Arduino MEGA. The problem is the sensor has no datasheet. I have got the relation between the temperature vs ...
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122 views

Can silicon temperature sensor (e.g. KTY84)'s polarity be inferred if it's inaccesible - polarity band cannot be visually checked?

I have two electric motors at my disposal, both equipped with KTY84-130 silicon temperature sensors (PTC thermistors). The sensors themselves are buried deep within the innards of the motors and I don'...
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Thermistor alternative using variable resister to identify specs and activate 18v Nicd charger?

I have a rebuilt 18V DC Powerhandle (battery)and a new charger. The charger won't activate charging likely because of defective foil wrapped component believed to be a thermistor. Can anyone tell me ...
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34 views

Regulating precision heating

Whats the simplest electr(on)ic(al) method for heating a coil or similar element to a specific temperature? Generating heat is easy; dictating and regulating a specific temperature is the hard part. ...
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70 views

Thermistor with LM358 Dual OpAmp Circuit Validation

Given the circuit layout here with a 9V input and the 10k ohm thermistor specs given, what at what temp would the green LED light and at what temp would the red LED light? I am expecting green to ...
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132 views

Do linear thermistors exist on the market?

I'm working on a project right now that requires me to use a thermistor to sense the tempertaure change with an op amp comparitor with hysteresis. Because of the non-linearity of a normal NTC or PTC ...
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67 views

Unknown component connected to white wire of rechargeable battery

I want to replace a battery for a TDK A26 speaker. (You can see a picture of the battery here). In the country where I live it is no possible to find a replacement, so I decided to replace the ...
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93 views

How to choose NTC thermistor?

I would like to make a siren on an UPS backup. I used this board with an 18650 embedded battery: https://www.aliexpress.com/item/32911096857.html?spm=a2g0s.9042311.0.0.24db4c4dn31JsH And this siren: ...
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88 views

NTC Thermistor Trigger LED

I'm wondering if anyone would be willing to help me with the basics here. I'd like to create a circuit, as small and simple as possible, with off-the-shelf components, that will allow me to turn on an ...
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5answers
156 views

Which is faster for an MCU? Calculating Steinhart-Hart or search in Look-up Table?

Let say we are to measure 0-100 degree Celsius in 0.1 degree resolution by using an NTC. For a particular MCU which is faster (takes less time to reach the result) : a) Reading NTC value via ADC and ...
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2answers
45 views

How to get NTC resistor's temperature vs resistor curve?

I have a thermistor MF52203 whose rated resistance is 20k. However, the datasheet seems like not providing the temperature vs resistor curve. Without this curve, how can I get the corresponding ...
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35 views

ntc half stack V (oltage?)

could somebody assist pls? im experimenting with battery pack for my cordless chainsaw blackanddecker 36v gkc3630l20 h1 36v. i created 36v battery pack from lifepo4 batteries instead of liion. it ...
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132 views

Need help with circuit design

For the class I am taking, we are to design a circuit with a thermistor in a wheatstone bridge. When the thermistor senses a temperature above 100°F or below 60°F it is supposed to turn on a ...
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61 views

Different markings, same thermistors?

I have three thermistors marked as follows: SCK 053 (dark green); NTC 5D-9 (black); DSC 5D-9...
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107 views

Applying heat to a transistor

I witnessed an experiment in which a transistor was connected to an led and a power supply. A lighter was used to heat up the transistor and this reduced the resistance of the circuit and made the ...
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Same thermistor model (103) with varying response

I was using thermistor model 103 to measure temperature of surroundings. To my surprise, when I checked different thermistors of the same model (103) bought from the same shop by changing them in the ...
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How many inrush current limiting thermistor do I need and where should I place them?

In most designs they place a single NTC thermistor in series before the bridge rectifier and in some two or four: simulate this circuit – Schematic created using CircuitLab Isn't a single ...
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121 views

What is a good (cheap) way to slow down a fan with a thermistor?

What is a good (cheap) practice to manage a fan with a thermistor? Here is what I think to do: simulate this circuit – Schematic created using CircuitLab This should work as temperature ...
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30 views

ADC reference voltage for nRF52840

I have designed an voltage divider bias with thermistor and the output voltage is given to adc pin of my nRF. But the internal reference voltage of my nRF is 3.6V so I did not get any accurate values ...
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221 views

ESP8266 (Wemos D1 mini) analog thermistor

I'm trying to connect my floor heating thermistor (NTC) to ESP8266 (at Wemos D1 mini board). But I'm unable to get good results. I get an approximation formula from this table (after I input my ...
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42 views

Thermistor - NTC 10 D-9 , steinhart-hart equation

I have the steinhart equation which is 1/T = A + Bln(R) + C(ln(R))^3 Where can I find an exact datasheet for NTC 10 D-9 ,(Please attach the exact datasheet with its temperature and resistance table ...
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128 views

Thermistor scavenge from digital medical thermometer

To be more specific, there's this thermistor I scavenge from an old medical thermometer. Something like this Cut to the chase, I connected my multimeter to the two wire of the thermistor where my ...
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229 views

How to calculate the value of the thermistor based on the output voltage of this circuit

I recently bought a board that consists of this circuitry. It came without an instruction whatsoever, so I have to figure out how to measure the temperature based on the output voltage at the To. The ...
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92 views

OTI-301 Infrared Sensor

I built an infrared thermometer using the MLX90614 IR sensor and an Arduino Nano. I needed a little higher temperature reading so I changed to the OTI-301 sensor hoping that it would work with the ...
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62 views

Determine possible thermistor value in multimeter

I have a Toptronic T835 multimeter that has a cracked component that looks like a thermistor. It is marked TR1 on the PCB. The only text on the component is first row [obscured character]B and second ...
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836 views

Hot Glue Gun NTC Heating Element?

I decided to take apart a cheap hot glue gun to see how easy it would be to replace the heating element to power it from battery instead of mains. I found the crystal heating element sandwiched ...
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242 views

Fake thermostat with resistor

I have a thermostat (think pt100) This should be connected to a heating solution. I want to fake the temperature from thermostat, so I was thinking to buy a resistor with the ohms at the temperature ...
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527 views

Why is my 10k NTC thermistor on average accurate to 2C

I am trying to figure out what is causing the 2C inaccuracy in my thermistor calibrations, my goal is to get my accuracy down to > .1C. I am using the KS103J2 10K NTC thermistor. To calibrate my ...
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177 views

Why do all my NTC thermistor have a PTC curve?

Suddenly, after testing my NTC thermistor (100k), the thermistor's curve started to turn into a PTC curve. To measure the resistance I am using an Arduino. I think its a hardware issue as I did not ...
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129 views

Does increasing the current make a thermistor more accurate?

For example, if the resistance/temperature ranges were fixed to 7500ohms (0C) and 400ohms (70C). At 30mA, the voltage would be 225V (7500ohm), and 12V at (400ohms). If the current was to 50mA, it ...
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456 views

Please help me to read schematic [closed]

I am doing repairs on a monitor of mine and I have to replace a thermistor. I cannot quite read the values of the thermistor on the schematic for the monitor. Can someone see the image and help me to ...
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219 views

Difference between standard and extended Steinhart-Hart equation

I looked up the data table for a thermistor I purchased and noticed it uses an 'extended' Steinhart-Hart equation. I'd like to understand the difference between these equations, such as how the D ...
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44 views

Battery heating issue

In my project, we are using Li-Polymer batteries. We have LCD and high-power components which will generate heat. We have an enclosure in which battery and LCD and other hardware will be fitted. We ...
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115 views

How did static charge ruin my control board?

We have a Thermia geothermal heat pump that was working fine up until we had a particularly bad thunderstorm. Lightning took out the power for a while and burned up a DSL modem, a router, and a IP ...
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57 views

Help to identify an uncommon thermistor

I am trying to identify a thermistor that was used in a "smart thermostat". It is a surface mounted small part (0603 form factor), bears no markings. I measured the resistance across at a few ...
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Thermistor probes wired in parallel

I have three temperature probes. Each probe consists of four sensors (NTC) with a common wire. The sensors wires are connected together and the common wire for each probe is available: The wiring ...
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What's the simplest way to calibrate a thermistor?

As a hobbyist who don't have access to lab equipment, it really seems impossible to me to be able to calibrate the thermistor that i have. Of course there are calibrated temperature sensors like ...
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110 views

Beta value of the thermistor

Why is that there are two different Beta constants for a same thermistor even though Beta constant depends on the material? For example: Murata's NCU15XH103D60RC has three different beta constants: ...
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79 views

Cryogenic PCB temperature monitoring

I'm operating a board at cryogenic temperatures (65 degrees Kelvin and higher) and need to monitor the PCB temperature. All of the standard surface-mount thermistors I've seen have operating ranges ...
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55 views

Thermistor in power supplies

a thermistor is commonly used in power supplies to limit inrush current. But once the thermistor is heated up the resistance is ideally 0ohms. If i switch the power supply on and off rapidly there ...
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195 views

Analog input like in a PLC: Thermistor or 0-10V

Depending on the configuration, PLCs can often measure 0-10V, resistance or 0-20mA on the same set of screws. How to use the same screw terminal to measure resistance of an NTC element, voltages in ...
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need help identifing parts

The first Green bit is a thermistor out of a fluke 374 clamp meter, but cant find the manufacture from the logo or what the number means. The other is a socket pin from a single wire connector, its ...

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