- Grounding

- Harness Shielding

- PDM Electrical Architecture

- DP Electrical Architecture

E U S O - B A L L O O N D E S I G N R E V I E W, 1 8 . 1 2 . 2 0 1 2 , C N E S T O U L O U S E

Pierre PRATAPC, Paris

Electrical Architecture

Grounding

CDR – 18.12.2012

Electrical Architecture 2

Grounding

Grounding principleIn order to avoid ground loops:

• Use of galvanically isolated DC/DC converters• Primary grounds (28V Battery) are connected on Mechanical ground of PWP • Secondary grounds of DC/DC converters are connected on a single point on Mechanical ground of sub-equipments (DP, PDM)• Mechanical grounds are connected together• Differential links (LVDS) between HK, CCB and PDM_Board, HVPS-1

CDR – 18.12.2012

Electrical Architecture 3

Harness Shielding

According to the recommendations of Johan Panh (EMC expert at CNES):•Primary power supplies : twisted pairs, not shielded• Secondary power supplies :

• LVPS-PDM <==> PDM_Board : twisted pairs, shielded, with shielding connected to mechanical ground (360°) on each sides (HF immunity)•HVPS-1 <==> HVPS-2 : shielded, with shielding connected to mechanical ground on both sides•LVPS-HK, LVPS1-DP, LVPS2-DP <==> HK, CCB, CLKB, GPSR, CPU, DST: twisted pairs, not shielded

•Differential digital links: twisted pairs, shielded, with the shielding connected to mechanical ground (360°) on each side

CDR – 18.12.2012

Electrical Architecture 4

Harness Shielding

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Electrical Architecture 5

PDM Electrical Architecture

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Electrical Architecture 6

Overview

PDM Electrical Architecture

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Electrical Architecture 7

PDM Board

PDM Electrical Architecture

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Electrical Architecture 8

HVPS

PDM Electrical Architecture

2 HVPS boxes in PDM box:HVPS-1:

2 CV DC/DC (28V & 3.3V) for ground isolation SPI I/F with HK LVDS I/F with PDM-Board (switch pulses) 3 DACs (HV tuning) 3 Cockcroft-Walton Converters

HVPS-2: 6 DACs (HV tuning) 6 Cockcroft-Walton Converters

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Electrical Architecture 9

HVPS

DP Electrical Architecture

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Electrical Architecture 10

Overview

DP Electrical Architecture

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Electrical Architecture 11

LVPS