Questions tagged [temperature]
Temperature is a property of a substance related to the amount of heat energy it contains.
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Using 1N4148 as temperature sensor for absolute temperature
Please forget the "why" for now, but I am attempting to determine the temperature of a 1N4148WS-E3 part by doing two measurements at different current setpoints. I've done some tests and ...
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Temperature-based motion sensor responding to a specific temperature range
I'm looking for possible options for a very specific temperature-based sensor, which could be used not just for movement detection (like PIR) but also to detect an object of a specific temperature ...
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Why does this circuit stop breaking down with a stronger flyback diode?
On a PCBA, I am using a LED driver to drive a high-power LED. Here is the schematics:
V_IN = 16 V
R_OSC is set so that the gate of the MOSFET is controlled at 150 kHz
R_CS is set so that the current ...
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Understanding PID controller output value
Consider a PID controller that needs to regulate the temperature of a small object. This will be implemented in software in a microcontroller.
A thermistor is closely bonded to a heater (a small 3 ...
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Reading PT1000 using op amp
I am looking for an op-amp circuit that can take in 24 VDC and output 0-10 V. It will be connected to my temperature sensor. I have found one diagram but I believe there should be some changes to it. ...
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Heating and cooling a liquid in a test tube electronically
I am automating a small-scale laboratory chemical process. One step is thermal equilibration of DNA in about 0.5 ml of aqueous buffer, which involves raising the liquid to 90°C and then immediately ...
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Linear regulator thermal information missing in datasheet
I'm considering to use UA78M33CKVURG3 in my design, so as with any linear regulator I have to make sure it will be able to handle the current draw in the worst case scenario. To calculate what the ...
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Constant temperature operation of microheater
I have been trying to make a constant temperature control for microheaters based on this wheatstone bridge circuit, using a trim pot to set the temperature setpoint. The purpose is to keep the heater ...
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Temperature of resistance wire
I am building a smoke generator based on heating mineral oil with a resistance wire. The smoke will be used for automotive diagnostics. I've read on this site where calculating the temperature of the ...
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Estimating battery temperature from current and voltage
Is there a way to estimate (even very roughly) the temperature a discharging lithium-ion battery can raise by knowing actual power delivered in a given time frame (in Wh)?
For example if it delivers ...
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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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Can a sine wave input be equivalent to a direct current signal?
I want to control the temperature of an electric oven. To do this, I must find its mathematical model, or transfer function.
To control the temperature of the oven I use PWM, which goes into a circuit ...
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Read 2-wire or 3-wire temperature sensor by unique connection to Arduino
I have 2 types of temperature sensors, 2-wire, and 3-wire RTD
I look on the internet and I've seen many schematics use the simple voltage divider for 2 wire sensors and the Wheatstone bridge for 3 ...
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Help identifying a temperature sensor on PCB
I have this PCB which is the motherboard of my pellet stove. It is reading a value "T Board" which is the temperature of the board. Now it's reading faulty values (86°C at ambient ...
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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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What "solder" is used in 1000°F-1200°F applications?
I got my hands on two decommissioned fuel cells, one of which I made functional. These are of the solid oxide type.
I decided to sacrifice the broken one to the reverse engineer gods. Inside the hot ...
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digital display [closed]
I was working on a design question (this is not homework, just personal practice).
So I have a temperature sensor with a non-linear response, and ideally I would like to design a digital display ...
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Do electrolytic capacitors lose lifetime during soldering in reflow oven?
Electrolytic capacitors service time is based on maximum operating temperature, among other things. When they are inside an SMD soldering oven, the temperature increases to over 375°C. Most of the ...
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Interfacing temperature system to moving coil
I was working on a design question (this is not homework, just personal practice). Can someone please help me get started or guide me through any worked steps please?
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Does a diode's tempco vary with temperature?
A pressure sensor's datasheet (https://meritsensor.com/assets/documents/pdf/HM-series.pdf) says its optional temperature sensing diode has tempco between -4mV/K and -1mV/K for -40° to 150°C. I was ...
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AD22103 temperature sensor seems to be heating itself up
The picture shows a AD22103 sensor on a prototype board for a room temperature control. The sensor is intended to measure air temperature, not the board temperature. There was originally a ADT7410 ...
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INA229 to measure temperature
I am basically using INA229 to measure current, voltage, power, and temperature of four 12V 100Ah batteries connected in a series-parallel combination. But before I ordered my sensors I read from the ...
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Puzzled by op-amp behavior in a temperature controller circuit
I have been trying to make a temperature controller based on a closed-loop control utilizing a Wheatstone bridge configuration and an op-amp. The temperature setpoint is adjusted by a trimpot. The ...
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How to give a "return" value?
I have a circuit. This is what it looks like, made in Proteus.
I’m trying to simulate temperature sensor. This is when the simulation is started. When the sim is ended, of course the blue LED is ...
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LM317 at low temperatures
The LM317 chip has an operating temperature range of 0 to 125 degrees Celsius. What happens if I use it at low (negative) temperatures? Will it work? What parameters will be affected by the ...
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How to change temperature and humidity sensor of XH-M452 thermostat?
there is a thermostat for incubator for poultry. People generally using this model XH-M452. But this thermostat has a problem, in high humidity environment temperature and humidity sensor of XH m452 ...
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Relay or switch that switches depending on the relative temperature
I want to construct a box whose lid opens/closes when the internal temperature of the box goes from lower than the external temperature to higher and vice versa.
The opening/closing is solved, now I ...
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How am I supposed to read this resistor thermal rating graph?
I am currently trying to learn to read resistor datasheets, specifically the thermal ratings.
I want to have a general idea of what the temperature of resistor will be at certain power.
Is there some ...
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Is silicone a thermal insulator or conductor?
I'm working on a circuit which will rest on top of the lithium polymer cell that powers it. A large portion of this circuit would be better off with minimal temperature drift so I'm planning to place ...
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PWM Fan Controller, inverted duty cycle
What I am trying to design is a 12 V DC controller for a PWM fan that uses a 100 Hz input signal and reversed duty cycle between 8 and 87 % to drive it. What I mean by reversed is that the fan is on ...
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DHT21 / AM2301 sensor not measuring humidity Arduino
Although there was a similar thread it was for Raspberry PI. This sensor should work out of the box with the Arduino and should be more advanced than the cheap DHT11/22.
I have this exact sensor: ...
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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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Can SiC diodes run at higher temperature than common silicon diodes?
For a usual silicon semiconductor, the junction temperature is rated at 150 degree C. That said, for lifespan reasons, the usual limit for junction temperature is around 100 degree C.
My question is ...
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Does the temperature affect the working of a PCB circuit? [closed]
I use an MP2305DS to convert 12V 5A to 3.3V 2A.
The PCB is in a standard IP68 box.
Does the temperature affect the operation of the PCB circuit?
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Temperature of radial electrolytic capacitors
I have been building boost converters. My current revision is working well at about 300 W, 55 V in to 86 V out. The main problem I now face is that the output capacitor is getting quite hot.
If I ...
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Will the equation result in higher junction temperature if adding a heat sink?
The formula below demonstrates the relationship between power absorbed and thermal resistance. I feel confused.
Won't adding more heatsink result in higher junction temperature according to the ...
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Temperature protection in an SMPS
In some power supplies there is OTP functionality mentioned as in the example (from this datasheet) below:
In this case, what does 80°C mean? Does it mean the PSU output will shut down when the ...
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What kind of temperature would I get with XL4015 voltage and ampere regulator converting 12 V to 6.5 V?
I have a guitar amplifier (Blackstar ID Core 10 v2). Its power brick has gone bad last year, and I have been searching for a power brick ever since.
This device works with 6.5 V, 3 A DC. It is pretty ...
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What happens if high via current flows in PCB?
If I used a via of 8 mils diameter with 20 um thickness. As per sierra tool calculator it can carry current of 1 A at 10 degree rise in temperature. What happens if the current is more than 1 A? When ...
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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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Ultra simple oven controlled resistor for analog temperature control
Background:
We're having a problem with a sensitive analog circuit. It has an analog supply voltage from a LT3045 Linear Regulator, whose output voltage is set by an external resistor. We're using ...
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Rise in temperature of MOSFET [closed]
How to calculate rise in temperature of IRF3205PbF MOSFET if Vds=10v and Ids=5 amps?
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How to map equivalent AWG wire gauge to PCB trace width?
There are some online calculators that let you calculate trace width based on PCB trace characteristics e.g. this one from digikey.
If there is a terminal connector on the PCB that connects solid AWG ...
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L7805CV operating temperature
I have an L7805CV powering an Arduino and a serial communication chip from a 12 V supply. Nothing else is powered by the L7805CV as the LED strip is powered via a TIP120 transistor and 12 V.
However, ...
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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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Identify the temperature sensor on a PCB
I have seven thermostats (for a fan coil central AC system) that unfortunately havd a big problem. When the relays (three big rectangles in black) are closed to turn on the fan they get quite hot.
The ...
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How can I design with the MF52B2 104F3950 thermistor?
I need to design a circuit that maintains a temperature, using this thermistor. Does anyone have general math that works for any thermistor that I can use to create a circuit with it?
I would not like ...
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Thermal design propagation calculations for a DCDC converter
So recently I've been doing some design for a DC/DC (this LMR33630) and now I'm doing the thermal design calculations using as a reference this Appnote, also from TI Accurate Thermal Calculations on ...
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Why is RTD immune to electro-magnetic fields? [closed]
Thermocouples may have added voltage & induction heating induced in a magnetic field, throwing off the measurements.
A Resistance Temperature Detector (RTD) is said to be a good alternative. Why ...
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Attach thermocouple to a PFC inductor
The inductor I am talking about is simply a toroid. I am attaching a thermocouple junction to this component with help from thermal paste and aluminum tape.
Anything I should be careful about in this ...
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