Thermistor
Contents
Thermistors
RepRap Thermistors
Each thermistor has a variety of special values such as Beta and Rz value. A variety of thermistors you may encounter when building a RepRap are listed below, along with the appropriate information.
RRRF 100K Thermistor
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- Beta: 3960
- Rz: 337254
- datasheet
Lookup Table For Temperature Sensor v1.x
- R1 = 0
- R2 = 4700
#define NUMTEMPS 20 short temptable[NUMTEMPS][2] = { // { adc , temp } { 1 , 929 } , { 54 , 266 } , { 107 , 217 } , { 160 , 190 } , { 213 , 172 } , { 266 , 158 } , { 319 , 146 } , { 372 , 136 } , { 425 , 127 } , { 478 , 119 } , { 531 , 111 } , { 584 , 103 } , { 637 , 96 } , { 690 , 88 } , { 743 , 80 } , { 796 , 71 } , { 849 , 62 } , { 902 , 50 } , { 955 , 34 } , { 1008 , 2 } };
RRRF 10K Thermistor
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- Beta: 3964
- Rz: 29000
- datasheet
Lookup Table For Temperature Sensor v1.x
- R1 = 680
- R2 = 1600
#define NUMTEMPS 22 short temptable[NUMTEMPS][2] = { // { adc , temp } { 1 , 608 } , { 60 , 176 } , { 70 , 166 } , { 80 , 157 } , { 90 , 150 } , { 100 , 143 } , { 110 , 137 } , { 120 , 131 } , { 130 , 125 } , { 140 , 120 } , { 150 , 115 } , { 160 , 110 } , { 170 , 105 } , { 180 , 100 } , { 190 , 95 } , { 200 , 91 } , { 210 , 86 } , { 220 , 81 } , { 230 , 75 } , { 240 , 70 } , { 250 , 64 } , { 300 , 4 } };
RS 10K Thermistor
- Beta: 3480
- Rz: 29000
- datasheet
Lookup Table For Temperature Sensor v1.x
- R1 = 680
- R2 = 1600
#define NUMTEMPS 20 short temptable[NUMTEMPS][2] = { // { adc , temp } { 1 , 922 } , { 16 , 333 } , { 31 , 266 } , { 46 , 231 } , { 61 , 207 } , { 76 , 189 } , { 91 , 174 } , { 106 , 161 } , { 121 , 150 } , { 136 , 140 } , { 151 , 131 } , { 166 , 122 } , { 181 , 113 } , { 196 , 104 } , { 211 , 95 } , { 226 , 86 } , { 241 , 76 } , { 256 , 65 } , { 271 , 52 } , { 286 , 34 } };
Thermistor Calculations
If you are using a non-standard thermistor, or you simply want more information on how they work, check these pages out.
Calculating Thermistor Beta
This is how you calculate the Beta value for a thermistor. You'll need this value if you plan on using a non-standard thermistor for sure.
Calculating PIC Temperatures
The PIC uses a capacitor and charges it through the thermistor. It sends the temperature back to the host as a timer reading. This page describes how it is calculated and how to choose the right capacitor.
