| 摘要 |
<p>A thermostat control has a temperature sensor (1) including a variable impedance connected to a measurement circuit (2) which has a proportional output of for example 100 mV per DEG C. The output is compared in voltage level detectors (5a, 5b) with preset voltages set on potentiometers (6a, 6b) and representing different temperatures. The output of one detector (depending on for example the time of day) is selected by relay (B) and output to relay (A) to switch a heater on or off. An LED bargraph array may be connected at (28) to display the measured temperature. <IMAGE></p> |
