| 摘要 |
1,226,963. Wave-energy position finding &c. MARCONI CO. Ltd. 11 April, 1968 [25 July, 1967], No. 34081/67. Heading H4D. In a radar P.P.I. display system a voltage representative of the rotation of the radar aerial is fed to a resolver 6, Fig. 1, which produces sine cosine (X and Y) components of that voltage. The X component is fed to the X windings of a deflection coil system 5 of a cathode-ray tube (C.R.T.) 4 through a drive unit 7. The Y component is fed to a gain control lead 10 of an amplifier 9, and also to a first input of an adder unit 8. Video signals, representative of received echo signals, are fed from a terminal 1 through an amplifier 2 to the brightness control of the C.R.T. 4 (via a further amplifier 3), and also to a second input of the adder unit 8(via the amplifier 9). Output from the adder unit 8 is fed to the Y windings of the deflection coil system 5 through a drive unit 11 having adjustable gain, so that either a circular or an elliptical field may be obtained. A voltage which is dependent upon a video signal is thus superimposed upon one of the resolved voltage components for deflecting the C.R.T. beam. The magnitude of this superimposed voltage is made dependent upon the varying magnitude of the said component by means of the gain-controlled amplifier 9. The rotor of the resolver 6 may be turned by a handle 12, to produce a corresponding rotation of the display. In another embodiment, the brightness control of the C.R.T. is fed from the output of the amplifier (9), Fig. 2 (not shown), instead of from its input. |
