| 摘要 |
<p>1,211,296. Automatic Temperature Control Systems. LICENTIA PATENT-VERWALTUNGS G.m.b.H. March 1, 1968 [March 3, 1967], No.10157/68. Heading G3R. In an automatic control system having a sensor 1 output compared with reference V<SP>e</SP> the error being amplified at 6 and passed through an element having an adjustable differential between on and off levels which control a switch 4 e.g. a pair of reverse parallel thyristors which energize a heating element 9, the output of amplifier is compared with a signal indicative of thyristor current through a delay element 10. In a specific embodiment Fig.3 (not shown) the output from a current transformer (10a) is rectified and compared with the error signal at (7) and passed through a differential element (8) into a thyristor control device (11). The frequency of operation of the system is made high to minimize the temperature errors. Direct current may also be used for the system by suitable adaption and by providing extra circuits for extinguishing the thyristors.</p> |
