Achieving Dome Slit Driving and Status Detection with Two Conductive Rings

At present, rotating domes with slit are still widely used in astronomical observations. They could rotate for 360 degrees and the telescope observes stars through the dome slit. In Xinglong Observatory of National Astronomical Observatories, some telescopes use five conductive rings to control the dome slit, but the state cannot be detected. In order to simplify the detection and control system and improve the reliability of the dome slit, a new type of dome slit state detection and driving circuit is proposed. This circuit only makes use of two conductive rings and two limit switches with diodes to realize the dome slit state detection and driving control. When the dome slit is in the limit state, the detection electric current is only able to transfer in one direction. And when the dome slit is in the middle position, it could transfer in both directions. The circuit has been successfully applied in several dome slits in Xinglong Observatory, for example, the 85cm reflecting telescope. The test and practical use show that the circuit could be well used in the state detection and driving control process; it greatly simplifies the system; besides, it could also serve the purpose of failure detection.