Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.arcetri.astro.it/~esposito/LBTprogres_report/october07/power_supply_startup_procV1.pdf Дата изменения: Thu Nov 8 16:04:07 2007 Дата индексирования: Sat Dec 22 09:19:33 2007 Кодировка: Поисковые слова: photosphere

Power supply block diagram and start-up procedure for the AGW #1
The current configuration of the power supplies of the AGW unit 1 is illustrated in the Fig. 1; the most of them are slotted in the Box39, with the exception of the BCU47 3.3V PS and of the PS for the PI driver of the Tip-Tilt, that are slotted in the Box47. The main PS is clearly the Power 8, since it powers the two analog front-end devices (LJ39 and LJ47) that have a great influence on the CCD read-out noise, plus the network devices (Mini-MC and GS108) the Reference Source and our custom boards (Power Controller, Auxiliary Unit Controller and Tip-Tilt Delay board). In the current configuration, when the AGW is off we still have some devices that are permanently powered on: the network devices (GS108, Mini-MC, the two TS8), the Power Controller board and therefore the Power 8 and the TS8 PS. We need these devices to identify the power-up command from the network and to switch the other PS on. We realize that this configuration can be optimized, to reduce the devices permanently on. Since it is not allowed to connect another cable or optical fiber to the AGW, the only way to power off the network devices is to implement a wireless connection directly to the Ethernet network. We can achieve this easily by building two custom boards, one connected to the telescope Ethernet inside the dome and another inside the AGW unit, with a few electronic components. There are different ways to implement this aim, but probably the simplest is to use a Ethernet interface like the XPort from Lantronix, directly (or by a microcontroller) connected to a radio antenna. On the other side we just need a microcontroller connected to the antenna and to a relay. With this configuration we could have just a small power supply and this tiny board permanently powered on. Once the power-on command is received, the relay enables the 110VAC to the Power 8 and to the TS8 PS and we get to the current configuration, where the Power Controller board is on and can decode the start-up command to enable the other PS. The resulting start-up procedure flow chart is illustrated in Figure 2. This procedure can also be improved, as the management of the ON/OFF commands of all the devices is preferable to be held by a unique device instead of four.

Figure 1: current status of the PS of the AGW unit 1 Moreover, most of these commands are managed by the BCU39 because a relay board from Microgate is attached on top of it. However, since these relay coils had caused in the past some interference resets of one device on the switching of another, they no longer drive directly their devices but by means of a second row of solid state relays, most of them


distributed near the target devices. Thus a unique device with a bank of solid state relays would simplify both the software procedure and the electronics.

Figure 2: Suggested start-up procedure flow chart. The modification with respect to the current procedure is the top control, that has to be handled by the wireless board