| 摘要 |
950,652. Converting. FERRANTI Ltd. March 27, 1962 [March 29, 1961], No. 11437/61. Heading H2F. [Also in Division G1] A three-phase signal is stabilized by application to the bases of three transistors having a common emitter load and converted to a twophase signal by a potentiometer having three supply points and two tappings. Photo-cells 324, 325, 326 generates signals 120 degrees apart on movement of a Moire fringe pattern 300. If the outputs of all the cells change in phase with one another due to light intensity variations, the increased current through the load resistor 334 raises the emitter potentials to reduce the transistor current, thus compensating for unwanted light source variations. The three-phase output from transistors 324, 325, 326 is applied to points P, Q, R on a resistor 338, and a two-phase signal in quadrature is picked off by tappings A<SP>1</SP>, B<SP>1</SP> which are adjusted to positions 45 degrees either side of the point Q. Specification 760,321 is referred to. |
