| 摘要 |
<p>1,206,834. Automatic speed control. SOC. ANON. DES USINES CHAUSSON. Feb.9, 1968 [Feb. 17, 1967], No. 6666/68. Heading G3R. [Also in Division H3] A saw 2, Fig. 1, cutting lengths off a moving strip 1, is arranged to move with the strip during each cutting operation at the same speed as the strip by a motor 6 controlled by a circuit comprising: an alternator 8a connected through a gearbox 9a to means 10 responsive to strip speed, an alternator 8 connected through a gearbox 9 responsive to speed of the motor 6, and a comparison circuit which applies a signal proportional to the difference in alternator speeds to the input of an amplifier 24 controlling the motor 6. The comparison circuit includes: rectifying and smoothing circuits connected to respective alternators and a differential circuit 15; and also a separate circuit 25 including tuned circuits 26, 27 and constituting a phase discriminator for precise comparison of the speeds. These 'coarse' and 'fine' circuits supply separate inputs of the amplifier 24. An alternative form or discriminator is disclosed Fig. 2, (not shown), and bridge rectifiers (30, 30a) may be used instead of the rectifying circuits 13, 14, the discriminator and the differential circuit in this case being connected in series to the input of the amplifier (24a).</p> |
