To improve the ventilation of the dome during the night, the telescope building has side ports that consists of 4 sets of 2 doors. For reasons of safety and the general objective of automating telescope operations as much as possible we are motorising the side-ports. A system similar to home sliding gates was selected, and a single unit including guiding rails and safety stops was ordered for testing. Since the side-ports move in a curve it is necessary to bend the rail to match the radius of the doors, which was done by a company on La Palma. The mechanical system was successfully tested.
To control the motors a system has been designed so the TCS can operate all eight door motors safely. The idea is to have a Programmable Automation Controller (PAC) commanded from the TCS, that in turn operates some modules that replace the push button handsets. The design will also permit semi-automated operation of the motors from push buttons on the dome floor. A mechanism for disengaging the motors so the side-ports can be physically moved will be added. A design of a control box that will contain the electronics for each pair of doors, including the control modules, mains filters, fuses etc has been made and the items for a single box ordered.
As the parts arrive, we will build-up a full system for one of the set of doors, that will be integrated in the telescope control system. Some modifications are consider to the control electronics that come with the motors to provide more flexible control of the door motion.
Thomas Augusteijn 2013-12-02