| 摘要 |
Temperature regulating apparatus for the control of temperature within an enclosure including a temperature measuring circuit which measures the temperature within the enclosure and a semiconductor heating circuit for generating heat responsive to the temperature measuring circuit. The temperature measuring circuit includes a resistive bridge with a temperature sensitive element as one of its legs, the output of the bridge being coupled to an amplifier for developing a temperature signal which varies as a function of the temperature within the enclosure. The heating circuit includes a plurality of transistors having their respective collector-emitter paths coupled in series so that a heating current can flow through the collector-emitter paths of all of the transistors. One of the transistors, designated the control transistor, has its base coupled to the output of the amplifier for controlling the heating current by the temperature signal. A current limiting circuit may be included in a feedback path around the control transistor. |
