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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Thermistor Replacement for 1990 Magnavox Model No. RK6076 PE03 CRT Color TV Set [on hold]

The Sams Photofact for this Magnavox Model No. RK6076PE03 color TV is 2741-1, and the Magnavox part no. for this 10.6 PTC COLD thermistor is 483511647001. The original thermistor for this set broke ...
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56 views

Fire Alarm Circuit using transistor

This circuit is working inversely on PCB as compare to Proteus Software. In software, when the temperature increases the buzzer is on. This is the desired output, but on PCB this circuit is working ...
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79 views

Constant current source to heat thermistor rapidly

My goal is to heat a thermistor as rapidly as possible. The thermistor has a resistance value of 10k Ohms at 25 degrees C, and a negative temperature coefficient. If I apply a constant voltage of ...
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4answers
77 views

How to apply HT gradually in a valve amplifier?

For valve amplifiers, it is said, that applying anode voltage before the valve is heated reduces lifetime and can have other negative effects on circuit lifetime. To avoid this, I want to add a ...
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4answers
84 views

Low side high side NTC measurement

I am using 100k NTC from Murata (SMD, 0603 package) for temperature Measurement. I will drive NTC (MCU_Output) only when i need to measure the temperature. Which of the following options is better? ...
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83 views

Determining The Parameters Of A Wheatstone Bridge

Good day, I am trying to use a Wheatstone bridge to condition a thermistor. The arrangement i have is shown in below. I need the following specifications. 10V output max from the bridge at ...
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66 views

does changing the cable length of NTC temperature sensor affect accuracy?

I'm using an off-the-shelf STC-1000 temperature controller, popular with homebrewers, that uses an NTC sensor to read temperature and switch on a relay to cool or heat when the sensed temperature ...
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1answer
96 views

Pros / Cons of LM35 and Thermistor, what alternatives?

I'm wondering which benefits/downsides I have using following thermometer? Is there something I'm overseeing? For easy temperature measuring, what would be the easiest? My Opinion is LM35, am I right? ...
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90 views

How to control the temperature of heating element

I am developing a heating application where temperature need to be constant. I am planning to set the temperature @ 200 degree C. when my sensor find the temperature exceeding the set temperature how ...
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2answers
94 views

Heating a li-ion battery for use in sub-zero temperatures

I have a design that I'm working on that is to be outdoors year round, with a 1 watt solar panel trickle charging a 6 Ah li-ion battery during the day. I expect there to be about 3 to 4 months of ...
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3answers
84 views

Could I use a surface mount thermistor to measure ambient temperature?

I'm working on a project where a device I'm using has this thermistor, a Murata NCP15WF104F03RC, to measure the temperature of the device itself. This is a surface mount thermistor. The implementation ...
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2answers
80 views

Temperature measurement into USB [closed]

I am trying to get a couple of temperatures into my computer. In my little lab I have about 50 thermistors that look a bit like this NTC-Thermistor. I now would like to get the temperature of all of ...
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29 views

Do DEOS (watchdog type) fluorescent starters harm lamps?

According to Osram Guide to Starters DEOS Starters (e.g. ST 171): In contrast to the starters in Section 4, the DEOS ® starter has an NTC resistor (negative temperature coefficient) and a ...
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503 views

NTC Thermistor Resistance Calculation for circuit using Wheatstone bridge, Op Amp & Arduino

I'm trying to work out the formula for thermistor resistance when using Wheatstone bridge/op amp circuit as opposed to a voltage divider circuit. I know for a voltage divider the \$R_t\$ value is ...
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2answers
119 views

Inrush Current Limiter Failure

I work for a company that builds electric motors, within the last few years they've started building control boards from brush-less dc motors. On the incoming power we have an Inrush Current Limiter ...
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2answers
66 views

What physical properties differentiates the classes of PT100?

I know how the accuracies are defined by the various classifications of PT100, eg Class A, Class B etc. What is it that is physically different between them?
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56 views

Energy Absorption By Series Resistance During Cap Charging

This question formed while trying to size a NTC thermistor to limit the inrush current to a capacitor. Assume the schematic below (with a fixed resistance): simulate this circuit – ...
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3answers
292 views

Re-building a Crock-pot controller - how are the heating elements powered?

After a few good years, my CrockPot gave up. It looks to me that there may be something wrong with electronics, and being and Arduino enthusiast, I thought I could re-build it. The symptoms are that ...
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228 views

Surge protection for SMPS

Can an NTC (Negative Temperature Coefficient) thermistor be placed before a MOV (Metal Oxide Varistor) for protecting an SMPS from inrush current and voltage spikes? Here is a drawing to clarify my ...
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248 views

Inrush Thermistor Bypassing

Hi I want to bypass an Inrush Limiter Thermistor. It is between the rectifying bridge and the smoothing capacitors, I was considering using a solid state device. After the rectifer current only flows ...
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2answers
92 views

instrumentation of V-divider dual-thermistor circuit

here's the circuit - voltage divider with 2 matched thermistors ("matched" means close enough that the measured temperatures when thermistors are right next to each other comes close enough for my ...
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2answers
141 views

Lots of thermistors but no readout

Back in Sep '12, Olin Lathrop answered a similar question about wiring a digital display to a thermistor, but my situation is slightly different from Jim McDerby's. I too have solar thermal panels ...
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1answer
431 views

How to place thermistor for reading temperature in NiHM single AA cell charger?

I'm laying out a PCB for a NiMH single AA cell charger following the AVR450 Application Note - Battery Charger for SLA, NiCd, NiMH and Li-Ion Batteries but I'm not sure where to place the NTC ...
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2answers
127 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 ...
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55 views

School Task with NTC

I need to solve the task shown on the picture. The first part is to calculate the temperature (in °C) from the NTC when Uv = 2V is. This means Iv is infinite. The given Values are: Uq = 12V, R1 = ...
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89 views

What is the “nominal temperature threshold” (NTT) on a thermistor?

I bought a thermistor together with my Arduino, because I thought it would be a good first project. I should have gone a different way, since it is obviously too complex for my level, but well, now I ...
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74 views

Max temperature of PTC heater, need tip

I have some difficulty reading specifications for PTC heaters, more specifically the ones on here. I understand that a PTC heater does not, inherently, rise above a specific temperature. In the ...
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2answers
2k views

PWM control of Peltier with Arduino+Thermistor [duplicate]

I currently have this setup and would like to add automatic control over the PWM based on a thermistor reading. Any insights?
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1answer
189 views

Where can I find a transistor similar to a 2n 3904?

I have what I believe is a 2N 3904 638 transistor. It measures 50MΩ at around 70°F. How can I find a data sheet on this? How would I go about finding a similar / replacement thermistor? PS: ...
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4k views

Thermistor control of peltier voltage with Arduino (for DSLR chill box project)

I am mildly familiar with electronics, mostly from playing around with electronics kits as a kid. That was a long time ago, though, maybe as much as 20 years ago. I am currently working on a cold or ...
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2answers
173 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 ...
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1answer
206 views

Low Curie Point PTC Thermistor

For a self regulating heater powered by a 12 V battery, I'm hoping to find a ~35 C Curie Point thermistor with a low "cold" resistance (for winter time, << 150 ohms). Most of these PTC ...
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2k views

Peltier heat resistor temperature controller, schematic issue

I've been having a problem with the following schematic: What I need to do: Two temperature controllers in order to create a temperature gradient. The hot side is a a little above room temperature ...
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1answer
132 views

Thermoelectric cooled Avalanche Photodiode sensor PCB

I'm designing a small PCB (max 5x5 cm) to bias and readout from an Avalanche Photodiode. Since the APD response varies greatly with the temperature, I want to use a cheap 12706 TEC together with a ...
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1answer
70 views

Table with termistor models with alfa

Hello I'm searching table with thermistors types and alfa (temperature coefficient). I need alfa for this formula : Mt = 1 - alfa/100*(Tmax - 20) I have some old ...
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3answers
195 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 ...
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1answer
259 views

Thermistor calculations using B-Parameter equation

I have a USUR1000-104G as seen here. From what I understand by these links here and here and using the b-parameter equation from wikipedia. I have the following values: \$ \beta = 3890 \$ \$ ...
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1answer
262 views

Trying to get readable value with Arduino/Thermistor setup

I'm trying to get a readable value from a thermistor. Right now it's printing 223.25 as my celsius value in my room. I know this is wrong. I'm using the thermistor model which is located HERE. The ...
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2answers
168 views

I'm getting 512 as a reading from a thermistor. Trying to convert this into something readable but having a hard time

I just recently purchased a KY028 Temperature Sensor located HERE. I was having trouble hooking this sensor up so I snipped off the thermistor and shoved it in a breadboard. I know it sounds tacky but ...
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3answers
352 views

How to trigger something once a day [duplicate]

What would be the right thing to use if I want the base of a transistor to be high for 12 hours and low for 12 hours? I ask because I would like to make a circuit that regulates temperature in a ...
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2answers
386 views

Help me understand this 4-wire RTD circuit

This circuit is a kelvin connection of 4-wire RTD. Resistance element is a 4-wire RTD (PT100). Can anyone tell me what can be the values of the resistors in the arms (RH)? And can anyone explain the ...
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1answer
175 views

What is the simplest way to toggle a relay with analog feedback?

I've been playing with electronics for a long time, but am fairly new to digital electronics, including using Fritzing, so apologizes in advance for that. I'm attempting a fairly basic ...
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1answer
228 views

Circuit or component to detect temperature change

I know this is a very simple question but I didn't find the answer. I have very less knowledge in electrical. I want a component or a circuit or whatever, which I can attach to a heating coil so that ...
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1answer
796 views

Simplifying opamp+thermistor circuit

I asked this question yesterday, which got answered and would work, but as I already stacked up on (dual) opamps I might as well do better. I've come up with this (probably flawed..) circuit, to ...
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3answers
184 views

Simplest way to measure 98 to 140 Ohm range with an ADC?

I have a thermistor that should vary between 98 and 140 Ohm and am looking for the simplest circuit that will convert this into something meaningful for a 10 bit ADC in the 0-3.3V range. Precision ...
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1answer
227 views

Constant Sum Voltage Divider With Thermistor/Temp Sensor

I need a circuit with a thermistor/temp sensor that will essentially emulate a pot. In other words, I need a voltage divider that varies with the resistance of the thermistor/sensor, but keeps the ...
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3answers
968 views

Arduino Rounding question

I have made a simple thermostat for controlling a 12V heater. The temperature range can be from 0 F to around 190 F. For some reason when the displayed temperature on my LCD goes from 99 to 100 ...
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2answers
4k views

NTC Thermistor circuit, ADC conversion, compute temperature

Here's the schematics of my NTC - ADC circuit, ADC 10bits, ADCVCC 2.56V Vin = 5V Someone can explain me how i get RT, the value of resistance of NTC from ADC value? thanks. I'm using the ...
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1answer
128 views

Safely detecting presence of 12v applied via exposed terminals for use with microcontroller

I have a board which contains a microcontroller and a 10k NTC thermistor (B57421V2103J62) wired to two external terminals, one of which is common with the board ground plane. The terminals are exposed ...
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167 views

Water detector for heating element?

I want to run a 300W heating element in a water bath, but I'd like to make sure that it isn't turned on by mistake when it's out of water, so I thought of connecting it to a controller and a sensor, ...