User instructions for the Low Voltage Crate of the CMS EE HV Distribution System [DEG 548] Version 1.1 : 20 th October 2011

Transcription

1 User instructions for the Low Voltage Crate of the CMS EE HV Distribution System [DEG 548] Version 1.1 : 20 th October 2011

2 1. Overview The DEG548 low voltage crate is designed to form part of the CMS ECAL Endcap HV system. As explained in [1], the HV system for each of the two endcaps comprises one CAEN SY1527 mainframe (with two A1735P HV power supply cards), four DEG547 HV distribution crates (see [2]), and one DEG548 low voltage crate. The low voltage crate: Provides low voltage power for the DEG 547 HV distribution crates. Provides a control signal interface between the HV distribution crates and the CAEN mainframe. Although each endcap should only need four HV distribution crates, the low voltage crate is capable of supporting up to five HV distribution crates. This allows extra flexibility when handling faulty supercrystals. Figures 1.1 and 1.2 show a low voltage crate. Figure 1.1: Front of low voltage crate DEG 548 User Instructions Page 2

3 Figure 2.2: Rear of low voltage crate. References [1] B. Camanzi, CMS EE HV Hardware System - User instruction manual. [2] M. Torbet, User instructions for CMS EE HV Distribution Crates [DEG 547]. DEG 548 User Instructions Page 3

4 2. Power supply The rear panel (see figure 2.1) provides the mains power inlet, with on/off switch, and five low voltage outputs. Each four-pin outlet provides the 5 V and ±15 V power supplies needed by a single HV distribution crate. (See section 7 for details of the pin-out.) If using fewer than five distribution crates, the unwanted outputs may be left unconnected. The mains power inlet includes a fuse. This fuse must be a T -type, 1 A fuse. Figure 2.1: Rear panel connectors. DEG 548 User Instructions Page 4

5 3. Control interfaces The connectors on the front panel (see figure 3.1) handle the distribution of the control signals between the CAEN mainframe and the distribution crates. All control signals referred to in this section are TTL signals Figure 3.1: Front panel connectors CAEN mainframe setup To operate correctly with the low voltage and distribution crates, the control interface switches on the front panel of the CAEN mainframe must be set as follows: Set NIM/TTL switch to TTL. Set ENABLE switch to LOC ENABLED. Set INTERLOCK switch to OPEN Control signals from CAEN to distribution crates In the HV distribution system, the control signal from the gen output of the CAEN mainframe needs to be fed into the control in inputs on the control cards of each HV distribution crate. To do this: The gen output on the front panel of the CAEN mainframe should be connected to the input marked 1 in figure 3.1. The outputs marked 2 in figure 3.1 should be connected to the control in inputs on the control cards of the distribution crates. If using fewer than five distribution crates, the unwanted outputs may be left unconnected. If operating the distribution crates without a CAEN mainframe, you may use one of the control bypass outputs (marked 3 in figure 3.1) as a dummy gen signal source. DEG 548 User Instructions Page 5

6 3.3. Control signals from distribution crates to CAEN In the HV distribution system, the control signals from the control out outputs on the control cards of the HV distribution crates need to be combined to produce a single signal which is fed into the interlock input of the CAEN mainframe. To do this: The control out outputs on the control cards of the distribution crates should be connected to the inputs marked 4 in figure 3.1. A signal must be present on all five of these inputs. If using fewer than five distribution crates, connect the unused inputs to some of the control bypass outputs (marked 3 in figure 3.1). The output marked 5 in figure 3.1 should be connected to the interlock input on the front panel of the CAEN mainframe Control bypass outputs The outputs marked 3 in figure 3.1 provide fixed 5V logic signals. They are intended to be used as dummy control signals as described above. DEG 548 User Instructions Page 6

7 4. General safety matters This equipment has been designed to meet the requirements of safety standard EN :2001 when used as part of the CMS EE HV distribution system or equivalent test rigs. Safety may be impaired if the equipment is used otherwise than as described in this document. DEG 548 User Instructions Page 7

8 5. Technical details Main input Mains supply voltage: 230 Vac. Mains supply frequency: 50 Hz. Maximum mains supply current: 0.5 A. Mains supply fuse: T -type, 1 A. LV power supply ratings The low voltage power supply ratings are as follows: +5 V - 6 A +15 V A -15 V A The current ratings shown above apply to the total current drawn from the five LV outputs. All outputs have overvoltage and current foldback protection. Control signals. All control interface signals are standard TTL/CMOS logic levels. Connector types Control interface connectors: LEMO 00. Output power connectors: 4-pole LEMO 2B. The pin-out of the output power connectors is as follows (where the pin positions are as seen from the exterior of the crate): Pin 1 (upper-left) Ground Pin 2 (lower-left) -15 V Pin 3 (lower-right) +5 V Pin 4 (upper-right) +15 V DEG 548 User Instructions Page 8