Tagged Questions

Temperature is a property of a substance related to the amount of heat energy it contains.

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2answers
41 views

Digital temperature detector

I am using LM95071 temp detector IC for temp sensing. Link for datasheet: http://www.ti.com/lit/ds/snis137d/snis137d.pdf Its a digital temp detector, it will show equivalent ADC count. But where we ...
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0answers
42 views

temperature compensation circuit using AD8515

Can I use AD8515 op-amp as temperature compensation circuit for pressure sensor? The picture shows how I intend to use it.
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2answers
36 views

PT100 sampling and accuracy

How accurate can I get temperature measurements if I repeatedly sample the data from a PT100 sensor. [Assuming I have a 16 bit converter]? What are the limits on accuracy and repeatability? Does the ...
1
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2answers
52 views

LM1084, should I leave the copper area connected to the TAB floating? [duplicate]

I am using the LM1084 in a DDPAK package as a 5V USB voltage regulator on 4-layer board. The TAB of the package is internaly connected to pin 2 (OUTPUT). I am not sure what to do with the copper ...
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3answers
130 views

How to make the hottest CPU temperature?

Besides just running an infinite loop, are there any tricks (like maybe cache misses?) to making a CPU as hot as possible? This could be architecture specific or not.
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votes
1answer
20 views

Max voltage output of DS18B20

I am using the DigiX board and trying to connect a DS18B20 (one wire temperature sensor). One of the issues with the DigiX is that it can only tolerate 3.3V on the I/O pins. I have been trying to ...
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0answers
23 views

Implementing Peltier temperature controller in a circuit

I need to measure the temperatures of semiconductors using a Peltier temperature controller. I am using a DT9818 (it's a USB collection board from what I have learnt). I would need to use software ...
0
votes
3answers
112 views

Can I put 2 voltage regulators (5V) in parallel to dissipate the heat better?

I connected around 10m of christmas light LEDs to a 5V voltage regulator (lm7805). It gets quite hot, put I can still touch it without burning my finger. So in is within its temperature range (120 C ...
0
votes
1answer
85 views

Temperature stabilization with PWM , PID controller with delay system

I am doing a project to control the temperature with PWM. I use peltier, thermistor,mcu and h-bridge mosfet. I want to reach a temperature with an error less than 0.05 and stay at that temperature ...
2
votes
2answers
66 views

Platinum RTD temperature sensor choices between 1000ohm and 100ohm

I heard the Platinum RTD temperature sensor are very accurate and I want to use it for my temperature measurement project (-40 degree to 80 degree range). I don't want to use other type sensors. ...
0
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2answers
63 views

What is this kind of temperature sensor called (Analogue Devices TMP36)?

I am reading about this stuff, and I have found clear definitions of thermocouples and thermistors online, eg on Wikipedia. But then I also found something different, e.g. what they at AdaFruit just ...
0
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3answers
77 views

Electrical resistance converted to wire temperature

I'm trying to get a formula that I can reuse to help me determine wire size and properties. The goal is to heat a 430' wire between 40-100F using 12 volts and 10 amps of direct current. Everyone is ...
1
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2answers
160 views

Will an electric heater coil stop drawing power when the surrounding temp is the same as the coil's temp?

I am trying to figure out if I can melt Aluminum cans using a heater coil from a toaster oven. I've already used q=mc∆T and q=m*(Latent heat of fusion) to figure out how much energy is required to ...
1
vote
1answer
80 views

Automotive Sensor - Excessive Ripple Noise

I'm designing an automotive oil temperature sensor based around a 3-wire RTD. This is my analog circuitry: U1 and U2 provide a 1mA bias on the RTD which is measured by U3 and gained up by U4. R5, ...
0
votes
1answer
65 views

Soldering CPUs/GPUs/FPGAs - temperature issue

I am thinking about making my own FPGA board and soldering using reflow. The tutorials I've read all say the process requires temperatures in excess of 220 °F. However, at least according to this ...
1
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5answers
179 views

How to generate Red light from a Blue-Dominated Spectrum

I have a white LED light source, the spectrum of which looks as follows --- want to filter out red light from this white LED source. But as you can see the spectrum dwindles in the red zone. And ...
2
votes
2answers
98 views

Heatsink or IC: how to determine root cause of overtemp?

I have a manufacturing situation where we perform a functional test on a board and we are getting frequent overtemperature failures from a BGA package with a heatsink on it. I would like to be able to ...
5
votes
2answers
148 views

What does 25°C mean on a transistor data sheet?

The background is, I'm trying to understand how well a typical transistor obeys the Ebers-Moll equation at constant (junction) temperature. See this snapshot taken from the Fairchild datasheet of the ...
0
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0answers
73 views

How to use LM56 to switch on/off a 2kW heater using a MOSFET

I have an oil heater at 220V/2000W so lets say 10A (maybe more when it starts?!). I was thinking of creating a circuit to switch the oil heater on/off with a LM56. Is it possible using a MOSFET ...
0
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0answers
42 views

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 ...
5
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4answers
2k views

Storing batteries in a refrigerator

The electro-chemical reaction is more favorable at higher temperatures. Consequently, when it is warmer, the batteries will perform better. This is also evident from practice: old batteries do not ...
4
votes
1answer
312 views

Weakest link in lifetime of electronic circuits

I'm working on a product, a single-board computer with an expected lifetime of 10-15 years, and I'm trying to identify the correct components to focus on for this. So far electrolytic capacitors ...
2
votes
3answers
230 views

Why is my analog temp sensor's signal so unstable?

I have an analog temperature sensor (TMP36 - datasheet - product page) and it is properly connected to an analog pin for reading its output. The Arduino sketch (firmware) works just fine. Everything ...
0
votes
3answers
88 views

Temperature Sensor probe lifetime

Need a good 1 wire temperature sensor, there is a lot of information about the DS18B20, but I see nothing about it's quality or expected lifetime. I was wondering which is the expected lifetime of a ...
0
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2answers
139 views

Cheap temperature sensor

For a project I need a cheap (less than 10 Euro) en simple solution to measure temperature. Accuracy is not really important, +/- 3 Degrees is acceptable. The desired temperature range is between 0 ...
1
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2answers
81 views

Fast-stabilising skin temperature sensor

We're currently trying to build a portable temperature sensor for the purposes of estimating human core temperature. This is a bit of an engineering problem (more to do with choice of materials than ...
0
votes
1answer
126 views

Analog temperature sensor with 100mV per 1 degree Fahrenheit

My devices only measure analog precision to the nearest 100mV. Most temperature sensors I can find only do 10mV per degree precision. Currently I'm using the LM34. Is there such a thing as an analog ...
2
votes
2answers
288 views

Arduino LM35DZ giving incorrect voltage

I have an LM35DZ which is temperature sensor, properly connected and reading strange values... like 1023. I've tried almost any code I could find regarding LM35DZ and Arduino, with the same results ...
0
votes
0answers
71 views

Simplest way to detect body heat

I need to detect how hot/cold a person is with a sensor (or multiple sensors) in close contact. I've looked at temperature sensors such as 18B20 and TMP36 but I'm not sure how to detect if a person ...
0
votes
1answer
87 views

What kind of temperature sensor is this?

What kind of temperature sensor is this? What would be the best method for getting a reading from it?
1
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3answers
81 views

How does a temperature sensor work?

How does a temperature sensor gather temperature? What is the mechanism used? More specifically I want to understand how the TMP102 sensor works.
1
vote
1answer
86 views

What is a suitable device for fast temperature process control?

Here is a ceramic heater catalog: product sheet These heaters can ramp up as fast as 150 degrees C per second. I am not entirely sure what I am searching for but let's look at my use case: Say I ...
1
vote
2answers
187 views

UPS batteries and hot/cold weather

I am designing a small network deployment for several buildings without temperature regulation. In planning the power, I can find very little about acceptable UPS batteries for these conditions. ...
3
votes
3answers
418 views

Boost DC voltage converter for wireless temperature sensor (1.5V to 5V)

I'm trying to design a wireless temperature sensor powered by one (or maybe two) rechargeable NiMH AA cell(s). The sensor should read and transmit the temperature every couple of seconds and remain in ...
0
votes
1answer
59 views

Variation of the amplifier input impedance by the temperature

I have a question, How can I calculate the input impedence in amplifier when the union base-emitter temperature is different (25C 100C, 50C ...)?
0
votes
1answer
59 views

How much is the current consumption of this sensor (tmp102)?

Here is the data-sheet. I just want to know how much time it takes to measure the temperature and how much current it consumes. I struggle when trying to find such info in the data-sheet so any help ...
1
vote
2answers
55 views

Is there a temperature sensor which triggers voltage output upon breaching a temperature threshold? [closed]

Is there a temperature sensor which will output a certain voltage if the temperature is below a certain degrees? e.g. Output 5v if temperature is < 0°C and output 0v if > 0°C. I'm trying to figure ...
1
vote
3answers
334 views

IC - Case temperature vs Operating tempaerture

When datasheets lists(MAX9744) that the normal operating temp are b/w -40 c to 85 c but the case temp should not be up above 165 c what are they suggesting. How come an IC work if its case temp gets ...
1
vote
2answers
45 views

Remote Temperature Readout

My house is on a giant hill. The city only provides enough water pressure to get me water half way up the hill. A long time ago a pump was installed in a small dugout on the side of the hill (about ...
2
votes
3answers
981 views

What is a suitable temperature rise for PCB traces?

I'm designing a PCB for a 10A relay and am trying to determine what the trace width should be. According to this trace width calculator, the biggest factors in the width are copper thickness, ...
1
vote
3answers
176 views

Cost-sensitive way to maintain a 220C temperature

I'm building a device which is designed to be built by people of varying skill and education levels. Part of it needs to climb to and maintain a temperature of 220C, but I don't need very tight ...
9
votes
1answer
449 views

How does soldering affect the internal bonding between the IC die and its package?

In other words, How does the IC fabricator solder these thin wires between the die and the pads and guarantee that the soldering iron temp (300C for example) on the IC pads won't desolder them?
0
votes
1answer
70 views

NXP i2c temperature probe locking up

I have an issue with an NXP SE95 temperature probe that has been working just fine up until now on other systems. At some point, either on boot or soon after, the probe will have some sort of meltdown ...
2
votes
2answers
547 views

Temperature measurement using LM35

I'm doing a project on beaglebone black and I'm interfacing a LM35 temperature sensor (datasheet) to one of the ADC pins of the beaglebone. As per the Beaglebone datasheets the reference voltage of ...
0
votes
1answer
164 views

Transfer function for a temperature sensor

I have a STLM20 temperature sensor with a transfer function of: V0=(-11.69mV)/C *(T) + 1.8663 V I have solved for T then it should be: T=85.543*(1.8663-V0) is this correct?
0
votes
2answers
64 views

Best temperature storage IC? EEPROM or SRAM IC

I am trying to integrate a temperature sensor along with the storage capability with it. Both temperature sensor and the storage device will be controlled by FPGA. Which device would be the most ...
0
votes
0answers
26 views

Setting the range of a grid thermal sensor

I have a question upon reading data through the thermal sensor row by row. For example, my sensor has a 4x4 grids, I want to read each row and by taking the average temperature per row divided by ...
-1
votes
2answers
161 views

Select channel from multiplexer to show temperature values in c programming

I have question regarding selecting channel from multiplexer. I'm trying to receive some temperature reading from the two sensors which shared the same address and while I'm using one sensor, it can ...
3
votes
2answers
182 views

IC's in high altitude and low temperatures

What happens to IC's when trying to operate them in extremely harsh cold and high altitude environments like Mt Everest? Could you take any ordinary phone or computer up there an expect it to work? I ...
6
votes
2answers
159 views

Soldering guidelines for freezer applications?

I'd like to do a home project where I take temperatures inside of my freezer and inside liquids. Liquid-compatibility aside, I'm mostly curious about whether or not anyone can recommend some best ...