| 摘要 |
<p>PURPOSE:To always make agreement the sweep line on CRT to a given direction, by converting the rotating angle of the antenna drive motor into pulse signal, and organically coupling the switch in the antenna drive section, the switch in the indicator and the pulse motor to drive the deflection coil. CONSTITUTION:The rotating plate 3 turned with the antenna is located in the antenna drive section 1 and optical detection element or Hall element 4 is installed near it. When the antenna 2 is turned, pulse signal is generated with the optical detection element or Hall element 4 and it is input to the pulse motor drive circuit 8 in the indicator 7 via the Schmitt circuit 5. The deflection coil 11 is linked to the rotary shaft of the pulse motor 9. The switches 6, 10 form the AND circuit and when the switches are ''ON'' contact, the pulse motor 9 is stopped. The stem direction of the antenna 2 and the sweep line in the indicator 7 are in agreement and in synchronizing rotation.</p> |
