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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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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Is it better using NTC or a proper temperature sensor?
I need to sense temperature for a lithium battery pack and a TO-220 package transistor. Would an NTC with voltage divider be ok or is it better to use a sensor like the LM36?
Note:
Measured ...
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Maintaining Linear Temperature / Voltage-Drop Relationship Across Thermistor While Stepping Down Input Voltage
I have a 6VDC power source that is exciting an NTC Thermistor R1 (resistance of the thermistor decreases as the temperature increases, but the relationship is not linear). There is a precision ...
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What is this Component labelled VR1
My Falmec Rangehood died. It looks like a component has burst on the controller board. There is actually smoke marks on the cover of the board.
It is next to F1 (non-existent), at the power entry. ...
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Simulating TEC current control input for MAX1969 Peltier driver
I am trying to simulate the control loop used to drive the CTLI pin of MAX1969 shown in the figure. In this application, a DAC is used to set the temperature. I used a regular resistor to represent ...
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How to reverse the behavior of a thermistor?
I have an NTC thermistor that reduces its resistance when temperature increases, but I need a circuit where resistance increases. Without using a different thermistor (or a microcontroller), is there ...
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NTC resistance/temperature deviation from nominal value
In the datasheet of this NTC I found this section:
I understand the steps, but it is not clear to me in the end where do I observe this temperature variation?
Here are my calculations:
Assuming from ...
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How do you turn on a NE555 Timer in general?
I have a schematic where I'm using an LM741 op-amp as a voltage comparator when its Vout is HIGH/+Vcc it "allows it to operate the 555 timer" and therefore activates the buzzer, and vice ...
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Thermal capacitance and resistance of conductive material
In my spare time I am working on this project:
I have a strip of conductive fabric material wrapped around my wrist that gets hot when current flows.
In addition to the measurements you follow with ...
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Adding a gauge affects the transistor switch circuit
Thanks to the help of this community I was able to build the following transistor switch circuit (details here, big thanks to @mathkeepsmebusy):
The circuit works and the LED illuminates based on the ...
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I have a rechargeable battery pack that is fully charged, the batteries aren't heating up and the charge controller won't shut off. Tick, Tick, Boom?
UPDATED AGAIN Sorry folks. I kind of jumped the gun with this question. I was patient and let the charger do its thing. The voltage increase flattened out as the rate of temp change increased. The ...
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NTC connection and noise
I have several times used an NTC in series a resistor to sense temperature with Arduino.
There can be two connections:
1) NTC between the power supply and the resistor (resistor going to ground).
2) ...
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Inrush current limiting for 120V AC powered circuit
I have a load that I'm powering from a 60W AC-to-DC converter that has a stated cold start inrush current of 30A@120V:
https://www.meanwellusa.com/upload/pdf/IRM-60/IRM-60-spec.pdf (the 15V output ST ...
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Does thermistor resistance vary with excitation current?
I am looking to use this thermistor for my temperature measurement application - https://media.digikey.com/pdf/Data%20Sheets/Cantherm%20PDFs/STS1_Series.pdf
The spec sheet mentions that the operating ...
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How does the thermistor activate/not activate a circuit?
I have this schematic which is temperature-dependent and would only make a sound once the heat detected is above the threshold of the NTC thermistor.
Can I get some help with circuit analysis?
How ...
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How to choose a diode and adapt a charging circuit so it can sense temperature from two battery stacks instead of one?
I have two questions regarding the schematic below.
Diode D3 (D2 in the datasheet) at location A3-A4 is not defined in the datasheet. R9 (R2 in the example) is sized at: 220Ω. The input voltage is 9V. ...
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Why do we use a voltage divider to measure the voltage of a thermistor? [closed]
Can someone explain to me when and why I should use a voltage divider when I design a circuit?
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Calculating thermistor value to replace fixed resistor
I have a circuit that uses a 5W 100Ω fixed resistor for inrush limiting. I'd like to replace it with a thermistor for better efficiency. I've not found any information referencing what resistance to ...
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Active thermistor giving skewed readings immediately when heating element turned on
For the purposes of experimentation and learning, I have constructed a circuit that uses a pair of 100 ohm 2 watt power resistors (in parallel for 50 ohms) to gently warm up a Microchip MCP9701A ...
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MAX11645EUA+T ADC Readings
I am having issues with ADC readings with MAX11645EUA+T. I have a 2 input ADC and am driving the inputs with thermistors buffered each with a voltage follower. The ADC works when I have both ...
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Output of ADC when no input is supplied
I am working with a Raspberry Pi 3b+ connected to an MCP3008 ADC to read sensor output.
When the sensor is not connected it gives some floating value (max. value). Is it possible to get a value of ...
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How serious is the 125 °C limit on an NTC thermistor?
I'm measuring a temperature for use in a thermal cutoff circuit at probably ~100 °C. Temperature exceeds 100 °C, microcontroller kills the power to it. Nothing novel here, but I'm not certain of the ...
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Noise on PCB trace influences NTC measurement
I have a general question regarding noise in PCB-Designs.
The PCB I'm currently working on is failing some tests on the RF side. I have scanned the internet for information, but there are no concrete ...
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How do I select a replacement ICL NTC thermistor for a PSU?
I want to replace an ICL (inrush current limiting) NTC thermistor in a vintage computer PSU (for Amiga 1200). This question is similar to 'Selecting an NTC for inrush current limiting', except that ...
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Resistor identification on a shunt PCB of a battery manager
A battery manager (Victron Energy BMV-602S) has a shunt which has a small PCB attached to it. The manager is able to monitor two batteries - "advanced" monitoring of a leisure battery (B1) ...
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NTC resistor to balance ambient temperature change on precision current controlled lamp
I use a constant current control design to control the current through the halogen lamp, which typically runs at 800-900 mA
Resistor MPN: PCS2512DR1000ET
DAC: MCP4725
simulate this circuit – ...
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Thermistor in Wheatstone configuration and ADC offset
Based on my rough analysis, I realized that by measuring a thermistor in a Wheatstone configuration, I could technically reduce the ADC offset error LSBs because we are substracting two divider ...
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What is thermistor Beta?
In the attached datasheet, I see the Beta value (K) is from 0degC to +50degC.
What does it actually signify in terms of usage in an application?
Like, how to understand that parameter if I have to ...
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A simple temperature sensing switch circuit to power a heater to prevent frost damage [closed]
Ok, up front, I am a huge noob at electronics design, not an engineer, just a dangerous man with a bunch of electrical components and a moderately good soldering iron, and just enough knowledge to ...
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How is a thermistor voltage converted into a temperature value?
Here is a list of thermistors I have found on Farnell:
https://uk.farnell.com/honeywell/135-104laf-j01/thermistor-ntc-100k-5-axial/dp/2112935
https://uk.farnell.com/ametherm/ms35-10018/ntc-thermis-...
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NTC physical simulation
I have a heating device that uses an external 47 kΩ NTC thermistor as the temperature feedback for temperature control.
What I would like to do is to make the NTC thermistor "wireless", so I ...
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Help with series NTC sizing
The inrush current of my 12V/10A rated SMPS exceeds the inrush current limit of a rocker switch so I need to dampen the inrush current by an NTC as shown below. (I know there are other methods but ...
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Modifying NTC thermistor signal
I have various devices with two wire NTC thermistors for which the curves are known.
I want to add a programmable offset to this thermistor. The lowest the resistance goes down to is about 500 ohms, ...
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How to get the thermistor with the lowest resistance?
My ASUS motherboard has one thermistor connector that takes a 10 kΩ thermistor.
I want to connect 2 or 3 thermistors to this connector but only the one with the lowest resistance to be read by the ...
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10 kΩ thermistor failures when connected to thermostat controller units
I have had many failures of these 10 kΩ thermistors when connected to heating thermostat controllers. I have contacted the manufacturer of the thermostat controller units and even they are at a loss.
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Is it safe to place thermistor on 18650 battery tab?
I'm making a BMS for a 3S1P Battery Pack, with the intention of using two thermistors to measure the battery temperature and let the circuit know when a battery is too hot or too cold. The battery ...
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Simulate a thermistor to fake temperature readings in heater
What I want to do
Control an old heater to avoid running during hours where kWh is expensive. Bonus: Getting a more even inside temperature.
How I plan to achieve this
I know there is a product where ...
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Instrumentation amplifier noise considerations
I am trying to understand and calculate the expected noise behind a simple NTC-bridge circuit where the signal is amplified by a instrumentation amplifier.
My goal is to measure 1 mK temperature ...
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Inrush NTC thermistor vs. frequent on/off
NTC thermistors has high resistance at normal temperature, thus limiting the effect of a surge of current during power-up. Its resistance lowers after itself heating up during normal operation, ...
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Understanding inrush current and mitigation methods
I want to be able to automatically switch on an AC-DC power supply edit for clarity: it's a constant current LED Driver [edited again for further clarity- the driver won’t actually be driving LEDs- ...
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