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MICE Decay Solenoid Quench Detector. Trevor Hartnett Daresbury Laboratory. Outline. Existing (PSI) Quench detection system How it works Why we want a replacement Replacement (DL) Quench detection system Comparison with existing system How existing system could meet other requirements
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MICE Decay Solenoid Quench Detector Trevor Hartnett Daresbury Laboratory
Outline • Existing (PSI) Quench detection system • How it works • Why we want a replacement • Replacement (DL) Quench detection system • Comparison with existing system • How existing system could meet other requirements • Progress report • When it will be ready
Existing (PSI) system • System overview • 3 Crates • Quench Detector • Power Supply • Battery back-up
Quench detection 7 Amplifier cards 7 Relay cards Latch and LED driver card Test points
Power Supply Linear power supply Switch mode ±15V and 12V power supply Circuit breaker control relays Emergency backup battery switching
Battery Backup • 4 12V Lead acid batteries • Series connected to provide 48V • Capacity 7Ahrs • Charged by a 1A, 48 V battery charger • Powered by the incoming mains. • LEDs used to indicate: • Batteries charged • Mains connected
Recent Problems • System is at least 27 years old • Concern that the electronic components are approaching end of life • sticking relay • capacitor failure in the magnet PSU which is of a similar age • ECS Group at DL asked to provide a Replacement QD system.
Replacement (DL) System • Follow original principles of PSI design • Update components • Use a modular design • Single PCB per quench channel • At least existing system user interface
Quench detection cards • Modular Design • Updated components • Isolation amplifier • Relay • Latching circuit • Isolation of voltage taps • Test points on each card
Power supply • 2x 230Vac to 48Vdc PSUs • 2x 48Vdc to ±15Vdc PSUs • 2x 48Vdc to 12Vdc PSUs • Control Relays
Battery Backup • The battery back-up crate will follow the existing design closely. • A 48V, 1A charger will be used to charge four 12V batteries in series. • The batteries will be 7 Ahr units.
Upgrades • Variable voltage limits on quench detection • Voltage range from 10mV to 110mV • A relay off indicator LED on each card • A reset button on each card • Test points are provided on each card • Greater level of output diagnostics • Tripped channel can now be identified • Status indicators of each power supply • Increased EMC protection to prevent nuisance trips
Progress • Quench Detection Cards tested • Power supply and battery backup still to be completed • Final testing of the complete system to be carried out before the end of July • Test of system with AFC in R9 at the end of July