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.
423 questions
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How to add a trigger-point to a thermistor/mosfet fan control circuit
This is more of a conceptual question from a non-EE about how to add a minimum-voltage trigger-point to a thermistor/mosfet fan-control circuit. I have been toying around with a thermistor circuit for ...
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Using a 10k Thermistor Across a Wide Temperature Range to Produce Linear Voltage Change
I have a 1/8 NPT thermistor that will be installed into a oil filter sandwich plate to measure oil temperature. Here is a link to it -> https://www.ebay.com/itm/276877376822
It is a 10k type, but ...
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How should PA12 be configured in an STM32-based thermistor voltage sensing circuit?
I'm working on an electric wheelchair controller based on the STM32G070CBTx. One part of the design involves temperature sensing using an NTC thermistor. The thermistor is included in a 3-resistor ...
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Is temperature sensing mandatory for parallel 18650 charging? [closed]
I was asked to repair a child's scooter that wouldn't charge. I was given the scooter without the charger, but this turned out to be a blessing in disguise because it was the wrong charger and if I'd ...
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Is the non-inverting input pin of my op-amp drawing significant current from my circuit?
I am trying to make a simple Schmitt trigger circuit with the TLV9302. Input voltage is 5V. On the non-inverting input, I have a voltage divider from the 5V supply using two 10k resistors, with a 1M ...
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Is this a thermistor, and if so, how can I find a replacement component?
I'm attempting to repair the circuit board in the external portion of a mini-split air conditioning unit. The mini-split is a Sanyo SAP-CRV93EH, and it was installed in 2004, so the model is over 20 ...
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Adhesives for attaching the thermistor to metal surface
I am repairing a laboratory incubator that is usually heated to 37 deg. C. There is an NTC thermistor used as a temperature sensor. The thermistor was glued to the heater wire and to the door surface ...
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Thermistor Steady State Resistance Calculation
I have the NTC thermistor “SL22 10009” and I have a query. My load (2fans) draw 2A@12VDC (1A each fan) and I want to learn what will be the resistance of the thermistor after the inrush current drops ...
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Would a thermistor cause noise in an RF power amplifier?
I'm currently working with an SOT-89 RF power amplifier that I am operating at ~400MHz. To measure the temperature, placed a large (1206) thermistor on top of thermal vias of the amplifier on the ...
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Can anyone help me in identifying this SMD part?
I assume it is a thermistor (PTC1) but I don't know its value or data sheet
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Three output pin drill charger with 2output pin BMS
I have this charger( a 12v drill battery charger, with 3 output pins, B-,B+,C)
I've bought it to charge this( a 3cell BMS with two charge/load pins, B-,B+.
The problem is charger wont start without ...
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Trouble with comparator hysteresis with NTC
When the NTC hits 80°C, the comparator will output LOW signal, but it will only be HIGH if only the NTC hit 75°C. So before the NTC hit 80°C, the circuit will work as intended. But the problem is when ...
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Why make so many variations of thermistors that are almost the same
I was looking at some thermistors, KTY81 in particular, and I was wondering why there are so many minor variances between them.
For example, a KTY81/221 has R25 resistance range of 1960 to 2000 ohms. ...
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Identification of componenet labeled 2310 from a dyson vacuum cleaner (v8) motorhead, maybe a thermistor?
I'd appreciate any help in identifying this component.
labeled 2310, no other markings
when disconnected vacuum's secondary "turbo" mode no longer functions
uses a 4pin plastic connector ...
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Which has the faster heating time - PTC thermistors or an etched foil heater?
In evaluating which technology has the faster heating time, given an equal size/thermal mass and an equal voltage, which would be more likely to reach a temperature of 80C faster - a PTC heating ...
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PTC Sensing circuitry
I'm trying to replicate a classic car coolant temp sensor. It hasn't been produced in over 20 years.
The original is a very linear PTC sensor with R25=300 Ω and a coefficient of 1,714 Ω/°C.
How can ...
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Why put a capacitor between VCC and a thermistor which is referenced to ground?
Just going through an old schematic here and noticed something strange:
there is a thermistor that is used to measure the board temperature, but it has a 0.1uF capacitor between VCC and the thermistor....
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Precise Electronic Measurements
I've been looking into various electronic components and noticed rampant 5%, 10%, and even 20% tolerances and accuracies not only in basic components such as capacitors, inductors, and resistors, but ...
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NTC inrush current limiter steady current rating
I understood most of parameters to choose NTC inrush current limiter, but couldn't understand steady current concept. In particular, how voltage comes into play.
For NTC to work as designed it has to ...
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How to calibrate a NTC Thermistor using a manipulated Steinhart-Hart Equation?
I have a NTC Thermistor setup in a voltage divider to with a Arduino such that it can read me the temperature using the Steinhart-Hart equation.
I initially calibrated the thermistor and measured its ...
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HP ESP120 Server PSU: What is this part for?
I have an HP ESP120 Power Supply that I am using for my RC battery charger (Yes, big batteries). Since the case is quite bulky I am in the process of building a new case.
I noticed a little separate ...
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Shining a Light When 2 Thermistors Deviate from Each Other
I have a heater that I am designing a control circuit for. As an additional level of safety I need to monitor 2 NTC thermistors and turn on a red led when their values differ by more than 5 degrees.
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How does DS18B20 temperature sensor get the temperature?
I’m trying to understand how the DS18B20 temperature sensors works. Is there a way to know whether it uses a diode or thermistor to calculate the temperature? I couldn’t find anything on the data ...
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Why is the output of the thermistor connected to the inverting terminal of the op-amp in this Texas Instrument IR thermometer schematic?
I am making an IR contactless thermometer by following this application note provided by Texas Instruments.
I have some doubts about a few connections in the schematic diagram provided.
Vref1 is ...
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How to Calculate Thermistor Resistance?
I'm working on an embedded system project using an STM32 microcontroller, and I need help calculating the resistance of an NTC thermistor from a specific circuit design. My background is in software ...
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Troubleshoot negative reading from thermistor sensor when the projector powers on
I'm in the process of fixing Epson EB-E500 projector lamp/temperature error. The projector turns on correctly, it displays the interface and after about 15 seconds the display shuts off and the fans ...
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Testing Thermistors and Resistor that reads as a Capcitor
I have an Air Source Heat Pump that has stopped working, I have an error code which is:
Faulty thermistor - dead short/open circuit.
There are 5 thermistors in total, one built into the power board ...
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How to apply a thermistor to my LED driver (TLC59116 PW package)
I currently use a TLC 59116 16-channel I2C LED driver in a 4 x 4 LED array driven by Arduino and would like to add a thermistor to the circuit design. I'm unsure where to add it or what supporting ...
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Adjusting underfloor heating thermistor resistance to match a different controller
I have DeviMat underfloor heating installed in my bathroom, presently matched to a Danfoss DeviReg "smart" thermostat. There's a matching Devi heating probe installed under the floor which I ...
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Is it better to use a NTC or a MOSFET to limit inrush current [closed]
I need help to design a circuit to limit the inrush current to a simple motor controller for a 36 V, 250 W motor on an ebike.
When turning on the battery to the controller there is a very large inrush ...
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How do I properly wire an SL-510-SS pyrgeometer to measure its internal thermistor resistance?
I've acquired an SL-510-SS pyrgeometer and am having trouble wiring the internal thermistor.
The manual gives the following description:
The manual also provides the following diagram:
I've ...
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Thermistor misreading
I'm currently working on a hotplate project with an ESP32, utilizing a 10k ohm NTC thermistor (B57550G1103F000) capable of measuring temperatures up to 300°C. However, I'm encountering issues with ...
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What's the output voltage
For the circuit shown in Fig. 3, the bridge is balanced when T=100 C. That is R1=R2=R3=R4=10k ohm. The thermistors are matched, and their resistance related to temperature by ...
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Thermocouple vs NTC
I want to test the accuracy of the NTC soldered in a current sensing board with a shunt resistor. For that, I attached a thermocouple type K to the junction of the shunt using epoxy and applied a ...
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Do I need clean Vdd when measuring resistance using ADC with Vref tied to Vdd?
I want to measure the resistance of the thermistor with the MCP3021 ADC using the voltage divider method. Since this ADC has Vref connected to Vdd and Vdd is powered from a DC/DC converter, I was ...
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Sanity Check: Does adding a second voltage divider change the properties of the original?
I have a thermistor configured in a simple voltage divider on a 5V circuit as follows:
I have no control over that part of the circuit.
The problem is that, at normal operating temperatures, that ...
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Choosing an NTC thermistor for inrush current limiting at 5 V
I'm designing a very simple circuit to enable a Raspberry Pi to power down safely in the event of a power outage.
It is comprised of a supercapacitor, a diode to prevent reverse current flow, and a ...
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Series resistor selection using B value
I am following this document to calculate the series resistor for an NTC.
Here the NTC used is NTCG164LH223HT1.Below is the snippet from the calculation section.
In the equation for RNTC the B value ...
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Can the B-value for NTC be used to extrapolate beyond the B range?
Most NTC thermistors have operating range way beyond the single B value specified in the datasheet. For example NTCALUG01A473HA has operating range -40..150C but only B25/85 specified.
Can I use basic ...
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Is it possible to multiplex thermistors for multiple cell battery configurations for the BQ25756 or other JEITA charge ICs for spaced apart cells?
I'm trying to figure out how to safely implement fast charging using the BQ25756 with a most likely 2s (though up to 4s is possible) layout of physically spaced out cells.
I haven't fully decided on ...
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Inrush current limiter thermistor acting up
One of the power amps I am working on uses a thermistor for inrush current limiting (SL15 25003) as shown in the schematic below (ICL1). When I was testing the unit it seemed to me that there was some ...
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Inquiry Regarding NTC Selection and Placement for ST L6924D LiPo Battery Charger
I am planning to create a lithium-polymer (LiPo) battery charger using the ST L6924D charging IC. Could you kindly recommend an appropriate NTC (Negative Temperature Coefficient) for controlling ...
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NTC Thermistor Life span?
is there a lifespan of how long an NTC thermistor should last when used as a current inrush limiter? was thinking it should go over 10 years but not sure?
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How does current flow in this temperature protection circuit?
Reading through the data sheet for a TP4056 Li-ion battery charger, I found the diagram of a typical application. I'm trying to fathom how the temperature protection circuit functions. I've found this ...
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Does it have to be the same thermistor?
I have two blown thermistors in a TV. I can't get the same part locally in the UK and ordering it from China will take a month at least so im looking for an alternative from local electronics parts ...
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Relay/Mosfet circuit for outputting source of highest voltage?
Currently using ntc thermistors to measure temperatures, I’m then using a comparison circuit to filter through a set of 3 thermistor-passed voltages (outputting the highest voltage).For overall design,...
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NTC layout for MOSFET temperature sensing
Here is a picture where there is a NTC (RT501) that is surrounded by a solder ring connected to the copper pour of the drain of the MOSFETs. Any reason why the layout the way it is with the ring? Also ...
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Can't get thermistor to work
I've got an NTC thermistor. This one, to be exact.
It has a table of resistances corresponding to temperatures. I've used it to derive a Steinhart-Hart equation using the NTC's resistances at 0°C, 20°...
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NTC wire in a replacement LI-ion battery has a different color [closed]
I am replacing a battery pack in a speaker. It is a Li-ion 18650 2600 mAh 7.4 V. I got a replacement from a shop in China claiming to be local. The replacement has an NTC and three wires just as the ...
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What thermistor for a TP4056 lithium charge module?
This TP4056 Li-Ion battery charger datasheet specifies an NTC thermistor be used for battery temperature sensing while charging. Is there any further specification I should know about the NTC ...
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