| 摘要 |
<p>950,917. Automatic temperature control. MONSANTO CHEMICAL CO. Nov. 13,1962 [Nov. 24, 1961], No.42898/62. Heading G3R. A resistance bridge 13-16 including a thermistor 13, has across one diagonal a transistor 11 controlling the changing of a capacitor 36 which triggers a uni-function transistor 28 discharging the capacitor through a resistor 30 which triggers a S. C. R. 38, thus passing current through a heater 21. As the required temperature is approached the changing rate of the capacitor 36 decreases as the bridge balances hence reducing the conducting period of the SCR in each half cycle. A resistor 22 and zene diode 26 stabilizes the voltage across part of the circuit. The sensitivity of the circuit is controlled by variable resistor 14.</p> |
