MullOverThings

Useful tips for everyday

How do you use a thermistor in a circuit?

How do you use a thermistor in a circuit?

To use an NTC thermistor in a detection circuit, put a small voltage across the thermistor. The resistance of the thermistor will reflect the temperature, with its resistance dropping rapidly as temperature increases.

What causes a thermistor to fail?

The cause of such failures are usually due to mechanical separation between the resistor element and the lead material, caused by handling damage, excessive heat, thermal mismatch, etc. The second most common failure mode is drift in resistance value as the thermistor ages, or parameter change.

Is a thermistor a sensor?

Thermistors, derived from the term thermaIly sensitive resistors, are a very accurate and cost- effective sensor for measuring temperature. Available in 2 types, NTC (negative temperature coefficient) and PTC (positive temperature coefficient), it is the NTC thermistor that is commonly used to measure temperature.

What devices use a thermistor?

Thermistors are used as temperature sensors. They can be found in every day appliances such as fire alarms, ovens and refrigerators. They are also used in digital thermometers and in many automotive applications to measure temperature.

What kind of resistor does esp8266-07 have?

Only ESP8266 – 07 and ESP8266 – 12 boards have ADC pin. -150k ohm resistor. We will use very simple and basic resistor-ntc circuit. Circuit is in figure1. Normally, if you search on internet you will see circuits that uses 10k ntc with a 10k resistor. On my circuit i use 150k resistor. Now i will explain why i am doing it.

How many different temperature values are there in ESP8266?

1 / 1024 = 0.00097 V resolution. That means, we have 298 different temperature values. As i sad this is enough for my project. Now we have solved hardware problem. But with this solution we have a problem with software.

Can you use ESP8266 ADC pin on Arduino IDE?

Functions that you can find on internet is for 10k ntc and 10k resistor and there is not enough explaniton about it. We need to find instantenious resistance of NTC. You can use ESP8266 ADC pin as A0 on Arduino IDE. In my project i use filtered analog read code. This is very effective and more stable.

Which is NTC thermistor for Raspberry Pi4?

A 10k series resistor and a NTC 10k (B=4050) are connected as voltage divider to the ADC input of the esp8266 (A0). The esp8266 is a wireless modbus slave to my Raspberry Pi4 OpenPLC runtime (running program is esp8266celsius.st).