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Lesson 23 Thermometer
Overview
In this lesson, you will use an LCD display to show the temperature.
Component Required:
(1) x Elegoo Mega2560 R3
(1) x LCD1602 Module
(1) x 10k ohm resistor
(1) x Thermistor
(1) x Potentiometer
(1) x 830 tie-points Breadboard
(18) x M-M wires (Male to Male jumper wires)
Component Introduction
Thermistor
A thermistor is a thermal resistor - a resistor that changes its resistance with
temperature. Technically, all resistors are thermistors - their resistance changes
slightly with temperature - but the change is usually very small and difficult to
measure. Thermistors are made so that the resistance changes drastically with
temperature so that it can be 100 ohms or more of change per degree!
There are two kinds of thermistors, NTC (negative temperature coefficient) and PTC
(positive temperature coefficient). In general, you will see NTC sensors used for
temperature measurement. PTC's are often used as resettable fuses - an increase in
temperature increases the resistance which means that as more current passes thru
them, they heat up and 'choke back' the current, quite handy for protecting circuits!