Questions tagged [temperature]
Temperature is a property of a substance related to the amount of heat energy it contains.
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Four MAX6675 give different temperature values at room temperature
I have designed a board with four MAX6675 thermocouple digitisers to measure temperatures at four different positions in a device. The board is connected to a Raspberry Pi, which reads the data via ...
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What is the accuracy of a thermocouple after calibration?
I'd like to use a thermocouple to create a general-purpose temperature probe. However, the accuracy is quite a bit lower than I want. Almost every source I look at (example) lists the accuracy of a ...
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High temperature reading of mechanically-separated body
I have a device with 2 mechanical parts. One side is stationary and can be connected to an electronic circuit with power. The second side is an enclosure that can have high ambient temperature (100-...
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Calculate the junction temperature of a MOSFET during pulse
Hi all I have a question regarding using a MOSFET for a constant current source. I have found this question with some answers but it wasn't clear to me yet.
I want to create a constant current LED ...
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Have I got a dodgy batch of TMP36 sensors
I bought some TMP36 sensors from Amazon.co.uk for a small project (ESP8266 NodeMCU temp sensors) and have struggled to get sensible output from them
I have tried reading them from A0 on the ESP8266 ...
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Measuring oscillator stability vs temperature
How do people measure frequency stability vs temperature? Is it by having the data of frequency vs temperature and then try to fit the curve and finding the temperature coefficient or by finding ((d(...
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Is the JEITA battery charging temperature standard accepted by EN62368-1?
EN62368-1 Annex M.4.2.1 mandates that the battery charging circuit shall 'stop charging' when the temperature of the battery exceeds the highest specified charging temperature (typically 45°C). ...
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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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Transmission distance with AM2320 temperature and humidity sensor
I'm about to work with a temperature/Humidity sensor, this sensor has to be wired more than 5m and less than 10 m to my PCB board, I was going to use the SHT3xx sensors, these sensors work with I2C ...
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Measuring Discharge Rate of LiPo battery
I am attempting to change the temperature that a 3.7v rechargeable LiPo Battery is discharged in and am seeing how this affects the capacity and discharge rate of the battery. My setup currently uses ...
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Creating battery pack with biased thermistor resistor network. How to ground if sensing externally
I designed a battery pack board for a customer that uses a multi-cell low-side (NMOS) protection IC. The protection includes OV, UV, OC, and OT/UT protection for the pack. The Overtemp and Undertemp ...
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How to calculate temperature rise of PCB polygon?
I'm designing a PCB where I have a polygon that carries current from one terminal to two pads, each pad should pull 33 Amperes, so a total of 66 Amperes running through that polygon.
How can I ...
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Three-wire load cell and HX711 weight compensation
In my project I use a 3-wire load cell (like this (3-wire 50kg), but mine were purchased from eBay) and an HX711 for weighing.
My wiring is like this (but I use an Arduino Mini Pro 3.3 V):
Apparently ...
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Thermal resistance - transistor temperature
I have a transistor with Vsupply = 24 VDC, VCEO = 45 VDC, and ICE = 20 mA.
How do I calculate the ΔT (rise in temperature) of this transistor? I would like to know what thermal resistance I may have ...
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Why does my SEPIC converter output more power at higher temperatures? What are the implications of this behavior?
I have a Pololu S18V20ALV SEPIC voltage regulator board that is wired to a high-amperage 5V USB power source on the input and a DC brushless fan on the output. The output is set to about 5.5V. ...
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What's the best approach to measuring an SMD component's temperature (using an SMD temperature sensor)
Question
Is there a temperature sensor (or else) which allows for the measurement of a copper pour on a PCB (and therefor the approximate temperature of a component)?
I want to read the temperature ...
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Why is the temperature sometimes expressed as a difference between two values and not an absolute value?
I was going through an IEC standard - 61439-1, table 6.
For aluminum, the standard specifies the value as 55K which is a temperature rise.
IEC 60085 specifies the class B insulator absolute value as ...
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Tuning motor temperature
I have a DC motor, running in two modes, slow and fast. I will need to run the motor in FAST mode only. The motor is already running for 10 years. The motor experiences variable load.
According to the ...
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Thermal Protection - NTC + Comparator + Hysteresis
I am looking to implement a temperature protection circuit using an NTC thermistor and a comparator.
Was thinking of using a hysteresis design I found in a manual by TI -
Do you think that's a good ...
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Buck regulator thermals calculations
Schematic:
Specification:
Vin = 24V
Vout =5V
Iout max = 8A
Freq = 0.691 Mhz
Assumptions: Good layout and FETs mounted on 1-2 inch^2 of copper.
Calculations based on this doc: https://www.ti.com/lit/...
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Alternative to MLX90614 IR Temperature Sensor : ISB-TS45D?
Has anyone tried using the "ISB-TS45D Infrared Thermopile Sensor" for measuring temperature using Arduino or any other board. I have used the MLX90614 sensor but is is much costlier than ISB-...
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Industrial PT100 temperature transmitter and ESP32 with micropython
I'm building a temperature controller using ESP32s and industrial PT100 temperature transmitters.
The transmitter I'm using is this:
MUR-HS-U
It has selectable temperature ranges and outputs 1-10V ...
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Voltage reference to drive multiple thermistors - high precision with op amp to supply current, or just generic voltage ref?
I would like to drive 8 thermistors in parallel.
They will be driven from 2.5V in a voltage divider. This will be about 20mA current draw.
I will be using a ratiometric measurement where the ADC ...
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Battery charging / discharging in a very challenging temperature environment
I'm searching for a solution to charge and discharge a battery pack. The current idea is to use 18650 cells, with 4 or 6 cells (~25-60 Wh) in series. The outside environment I'm dealing with can be ...
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How can I turn off a MOSFET when the temperature rises?
I am using a MOSFET as a pre-regulator.
When the voltage is too high, the temperature of the MOSFET is getting too high. (Even if I take 15 mA current.)
As a safety precaution, if the junction ...
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Temperature rise in the inductor?
I have a customized inductor which is of E70 core. I would like to calculate the temperature rise in the inductor.
Ac copper loss= 5W, DC copper loss 2.5W, core loss 8W (according to steinmetz). I ...
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UV protection for character LCD
I am using 20X4 character LCD display.
Like these: https://www.alibaba.com/product-detail/big-size-20x4-line-white-color_62471561311.html?spm=a2700.pc_countrysearch.main07.78.2bafd2a7u344W2
The ...
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Why is the MCP23S17 device getting too hot suddenly and randomly?
Circuit is a Raspberry Pi 4A SPI master node talking with one MCP23S17 device. I'm testing the single-circuit version in a protoboard.
We are using A bank GPIOs for reading, and B bank GPIOs for ...
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Calculate the Thermal Resistance (Junction to ambient) from Thermal Resistance (Junction to mounting base)
I have this MOSFET - MOSFET Datasheet
I want to calculate the maximum junction temperature of the MOSFET part. I have calculated the power dissipation.
In the MOSFET datasheet, there is only Thermal ...
user220456
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TMP36 sensor temperature spiked to 200+ (actual temperature of the component)
I've been learning Arduino and playing with the TMP36 sensor, trying to read temperature of my room. To do that I've assembled a super-easy scheme just to read the values to Serial monitor, something ...
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Will the resistance of the certain valued resistor decrease or increase at cryogenic temperature?
I tried to measure resistance of 332k Ω while dipping in liquid Nitrogen (cryogenic temperature) I got the resistance value near about 458k Ω, doesn't it contradicting "Resistance should increase and ...
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Board is getting reset when I lower the temperature in Thermal Chamber
I have a board which I put in the thermal chamber.
I increase the temperature inside the thermal chamber to 85degC. Soak it for 2 hours and note some readings.
Then, when I change the temperature to ...
user220456
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Multiple temperature sensors - One output
I'm a plumber and I'm not able to find a commercial product that fits my needs, so I'm wondering if it would be feasible to build it from scratch... I'm familiar with basic understanding of electronic ...
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Temperature vs. lifespan: the 10 degrees Celsius 'rule'
TL;DR: What's the origin of the 10 degrees Celsius rule?
I have heard many times that for every 10 degrees Celsius, the lifespan of components gets halved. There are many documents on the web quoting ...
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Heat transfer coefficient in a Module Baseplate
Today, for example in a power IGBT module cooled by a heatsink, it has been found that the heat transfer coefficient (htc) distribution may not be uniform across the bottom surface of the module ...
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Magnetic Field Strength Measurement at Extreme Temperatures
Hi I have just been given a project at work and we are magnetically stress testing DUTs at extreme temperatures going from -40 Degrees Celsius to 200 Degrees Celsius, I need to come up with a way that ...
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PID neural network temperature inertia
I am using a PID Neural Network (PIDNN) algorithm to control a multi-zoned temperature hardware. The aim of the algorithm is to minimize the error with the Backpropagation rule and weights updating.
...
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Soldering sheet busbars to PCB concerns
Hello fellow engineers
I have decided to solder busbars to a high current pcb , but i have 2 concerns :
Does soldering a flat busbar (shown in left image) could cause thermal stress and deformation ...
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Have 1 temp sensor send temperature readings to 2 seperate temp gauges
My old truck (fuel injected '92 Ford Ranger) has 2 temp sensors, located where the hot coolant leaves the engine.
One sensor goes to the ECU, which alters the amount of fuel which is delivered to ...
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MSP430G2553 Reading from ADC10 Temperature with Button ISR
This is my lab assignment. When I press the button, the red LED toggles on and off. But, I can't seem to read anything from it. Also, there's an empty loop in the code, but I don't know what to insert ...
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What are the materials needed for boiling milk alarm sensor?
I have recently bought raspberry pi to start working on it. I have never ever used it before. I am thinking of doing very basic task of led bulb on/off for getting into it. I am curious on developing ...
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How can the temperature drift in this unusual absorption detector be reduced?
I am using this simple circuit in a sensitive hand-held probe to detect metals in the ground. It works very well except for the temperature drift.
The drift means having to often re-adjust P1+P2, ...
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NTC Thermistor selection for high temperature where beta value needs to be > 22000
We would really appreciate some help with finding a thermistor (and accompanying resistors) in order to do some current limiting in high-ambient temperatures. The circuit comes from the LT3741 ...
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PID tuning single input two output with changing setpoint
I am operating the process in the image below, where I am using a recirculating heated/cooled bath (RHCB) (Polystat 12122-56) that externally circulates hot water through a heat exchanger (HX) and ...
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MAXIM31855T thermocouple chip, is there a through hole equivalent that works on the spi bus, having problems with SMD routing
I need to produce a circuit board to measure 16 temperatures from different thermocouples of types J and T, Maxim has the perfect chip, the MAX31855(T,J), the only problem is that it is surface mount ...
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Relation between Digital frequency counter and temperature
This is a homework question, I can normally solve the problems on freqeuncy counter but I never did with temperature related frequency counter problems.
A digital frequency counter has these ...
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Arduino building a pulse proportional thermostat
I'm not much of an engineer, but I have worked with arduino. I'm looking to see if it's possible to build a pulse proportional thermostat with a probe and an arduino. Any recommendations on where to ...
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Why am I getting such widely ranging values from this TMP36 in this circuit?
Background
I have the following circuit built on a breadboard at this time.
I'm powering it off computer USB and a 5 V, 2 A wall wart (via USB) into the Nano Every (which is located on the breadboard -...
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Battery charger failure
I'm using this Battery Charger IC - MCP73831.
I am using a SOT-23 package.
My input is 5V, the output Vbat charge regulated voltage on the Vbat pin is 4.2V and the maximum charge current is 340mA.
So, ...
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DS1620 in SMT format has different output than the dip version
I'm polling a DS1620 and converting the raw data to degrees F and it works fine using the dip 8-pin chip. I bought some SMT chips and soldered them to adapter boards and tested them using the same sw/...
