TE Technology TC-720 - Manual (Page 95)

The controller is not limited to using thermistors. It can also use such devices as the LM335 where its voltage varies linearly
with temperature. The following example shows how to set up the controller to use an LM335.
The LM335 provides a linear output voltage directly proportional to temperature at 10 mV/K. It provides a range
from -40 °C to 100 °C. The LM335 has an output of 2.98 V at 25 °C (298 K): at -40 °C, the output is 2.33 V, and at 100 °C, it is
3.73 V. Recall from the previous example that we have 129 index locations spanning over a 0 V to 5 V range. The volts per
location equal 5V/128 = 39.06 mV/location. This leaves 60 (2.33 V/0.03906 V = 59.65) locations at the low end of the table
that would be filled with the low temperature value of -40 °C. The upper end of the table is filled with the upper limit of
100 °C in 33 locations [(5 V – 3.73 V)/0.03906 V = 32.6]. The remaining 36 locations (129 – 60 – 33 = 36), are used to map
the temperature range of the LM335.
Below is a table showing the temperature values corresponding to their respective index locations. The index locations are
shown for reference only. As in the previous example above, you would only enter the temperatures in a single column to
create the .csv file.
1 -40 27 -40 53 -40 79 31.54 105 100
2 -40 28 -40 54 -40 80 35.44 106 100
3 -40 29 -40 55 -40 81 39.35 107 100
4 -40 30 -40 56 -40 82 43.26 108 100
5 -40 31 -40 57 -40 83 47.16 109 100
6 -40 32 -40 58 -40 84 51.07 110 100
7 -40 33 -40 59 -40 85 54.98 111 100
8 -40 34 -40 60 -40 86 58.88 112 100
9 -40 35 -40 61 -38.78 87 62.79 113 100
10 -40 36 -40 62 -34.87 88 66.69 114 100
11 -40 37 -40 63 -30.96 89 70.6 115 100
12 -40 38 -40 64 -27.06 90 74.51 116 100
13 -40 39 -40 65 -23.15 91 78.41 117 100
14 -40 40 -40 66 -19.24 92 82.32 118 100
15 -40 41 -40 67 -15.34 93 86.23 119 100
16 -40 42 -40 68 -11.43 94 90.13 120 100
17 -40 43 -40 69 -7.52 95 94.04 121 100
18 -40 44 -40 70 -3.62 96 97.94 122 100
19 -40 45 -40 71 0.29 97 100 123 100
20 -40 46 -40 72 4.19 98 100 124 100
21 -40 47 -40 73 8.1 99 100 125 100
22 -40 48 -40 74 12.01 100 100 126 100
23 -40 49 -40 75 15.91 101 100 127 100
24 -40 50 -40 76 19.82 102 100 128 100
25 -40 51 -40 77 23.73 103 100 129 100
26 -40 52 -40 78 27.63 104 100
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