PIXEL WEEK September 1999 S. Kersten University of Wuppertal 1 Status of Interlock Box New Interlock Box: NTC -I Box q relative changes in resistor values 4% (NTC) instead of 0.4% (Platin) simplifies the circuit q larger value of resistor allows 2 wire measurement (charge pump in the circuit not necessary any more, saves ca. 9 SFR) q common thresholds for all channels q no optocouplers q 16 channels on one board (before 8 on 2) shooting temperatures T high + 0.9º C (+0.1º C signal is reset) T low º C (-16.9º C signal is reset)

PIXEL WEEK September 1999 S. Kersten University of Wuppertal 2 Status of Interlock Box theoretical max. error of the I-Box circuit: +/- 0.2º C test measurements for 32 channels with potentiometer, 60 m cable connected to input: all channels inside theoretical limits what does it cost? Prototype 8.5 SFR / channel without costs for mounting of components, but very expensive distributor for electrical components (small samples with fast delivery) compared to old I-Box: prototype 40 SFR production 25 SFR estimated new production costs: 5.5 SFR

PIXEL WEEK September 1999 S. Kersten University of Wuppertal 3 Status of Interlock Box NTC Resistors: wanted value: 10 k  size: SMD 0603 tolerances: 25º C and 1% for B-value 30 companies contacted: Semitec (Ishizuka, Japan) : 0.9 SFR TBPS (Taiyo Juden, Japan): 0.3 SFR per 4000 pieces q irradiation tests in August (thank you to Jens): 3x10 14 p/cm 2 not accessible till now q B-value requires further investigation for example: Semitec - 6º C max. deviation 0.5º C NTC Resistors: wanted value: 10 k  size: SMD 0603 tolerances: 25º C and 1% for B-value 30 companies contacted: Semitec (Ishizuka, Japan) : 0.9 SFR TBPS (Taiyo Juden, Japan): 0.3 SFR per 4000 pieces q irradiation tests in August (thank you to Jens): 3x10 14 p/cm 2 not accessible till now q B-value requires further investigation for example: Semitec - 6º C max. deviation 0.5º C

PIXEL WEEK September 1999 S. Kersten University of Wuppertal 4 Status of Interlock Box TIS: q fail save? q logic: okay 1 error 0 q short and ´long´ circuit in lines between temperature sensor and I-Box I-Box and the detector power supply q missing one or several power supply lines (of I-Box) ê add additional line to control the +5V and its return ê remote test possibility

PIXEL WEEK September 1999 S. Kersten University of Wuppertal 5 Status of Interlock Box Combination with Local Monitor Box: actual input impedance 800 k  request to B. Hallgren for a higher input impedance next steps: q systematic measurements with NTC resistors: reliability, tolerance limits, irradiation q irradiation of I-Box q study complete system (I-Box, NTC resistor and long cable)