tailieunhanh - Electronic Navigation Systems 3E Episode 3

Tham khảo tài liệu 'electronic navigation systems 3e episode 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Speed measurement 49 1. pressure chamber 2. pressure rod 3. lever 4. pivot 5. electric start contact 6. reversible motor 7. main shaft 8. spiral cam 9. lever 10. constant speed motor 11 distance counter 12. screw spindle 13. friction wheel 14 distance cone 15. distance shaft 16. servo transmission system 17. servo transmission system 18. gearwheels 19. gearwheels 20. speed servo transmitter 21. remote speed indicator 22. servo receiver Figure The mechanical speed translating system of the SAL 24 pressure tube log. Reproduced courtesy of SAL Jungner Marine. 50 Electronic Navigation Systems along the cone to the rim. The distance indicator 11 is driven from the constant speed motor 10 via the cone. The nearer to the rim of the cone the friction wheel rides the greater will be the distance indication. Revolutions of the distance shaft 15 are transmitted to the remote distance indicator via the servo transmission system 16 and 17 . Operation of the SAL 24E The SAL 24E utilizes the same system of tubes pressure tank and diaphragm to convert pressure variations due to speed to electrical pulses suitable to drive the electronic circuits that replace much of the mechanical arrangement of the SAL 24 log. The distance integration mechanism with servo cone and counter has been fully replaced with electronic circuitry. As previously described when the vessel moves forwards the dynamic pressure acting on the underside of the diaphragm causes it to move upwards forcing the pushrod upwards. As shown in Figure this causes the pushrod arm assembly to move to the right on the pivot increasing the Figure Pressure mechanical assembly of the SAL 24E electronic pressure speed log. Reproduced courtesy of SAL Jungner Marine. Speed measurement 51 LVDT board UDCK 8V 5V ov -100 24V . Domodu. lator 8V regulator 5V regulator 8V regulator -10 Pu se Ref. Contr. servo board USER 24 V switching amplifier control - 5V - 8V Status 200 pulses per nautical mile 10 100