Low voltage notes 24.7.03

1
Low voltage notes (24.7.03)
Detector
1)
DC voltage
Transformer, rectifier, simple filter
Low Voltage Regulators, LVRs
400Hz
One to 5 VFE cards

• But
• No specification, DC supply not stable enough
• No tuning to special ECAL needs
• Difficulties, line regn, load regn

Detector
3 phase or single A/C standard mains
2)
Regulated power supplies
Want 10 tower trigger module, 250 ch
LVRs, one to 5 VFE cards
Large cables or bus bars
Weiner/CAEN at carts or counting room

• But
• cant get enough power from existing regulated
  power supplies
• Proposal to parallel up from the P/S
• if want 3A, but max 2A, need 2 together for
  capacity BUT must equal current sharing, where is
  sense wire?
• Ie for 250 ch, potentially 5 different senses
  going back to ganged P/S. What will be defining
  what?

2
Low voltage notes (24.7.03)
Bus bar modularity 28 x 70 mm2 bus bars, 1 bus
bar is 70 mm2
4 voltage rails 5V Dig 2.5V Dig 5V
Analogue -2V Analogue The sense at end of each
substantial bus bar on Dee, if needed, But STILL
no P/S with enough current o/p Bus bars per
Quad ??????????????