Heatsinks for the FMC Fine Delay
This page summarizes the heatsink testing results.
Fine Delay on SVEC (lab test)
Test evironment:*
- crate: 20-slot Wiener VME64x
- crate contents: single SVEC in VME slot 5 with the card under test in FMC slot 2 and FMC TDC in FMC slot 1
- fan speed: 1200 RPM (minimum)
- ambient temperature: 20 deg Celsius
- warm-up time: 8 minutes
Results:*
| Serial No | Configuration | Temperature (degrees Celsius)
|
| CR37 | no heatsink | 59.7 |
| CR09 | small heatsinks on delay and PLL chips | 51.7 |
| CR01 | big heatsink in the rear of the card | 58.6 |
| CR03 | both heatsinks | 52.3 |
Conclusions:*
- big heatsink gives very littl temperature drop (1 degC can be
considered measurement error)
- small heatsinks glued on the chips give improvement of 8 degrees C
ELMA operational crate full of Fine Delays
Environment*
- crate: 18-slot ELMA VME64x
- contents: 6 SVECs with 12 Fine Delays in total
Results:*
| VME Slot | FMC Slot | Temperature (degrees Celsius) |
| 7 | FMC1 (lower) | 42.7 |
| 7 | FMC2 (upper) | 56.1 |
| 8 | FMC1 (lower) | 61.8 |
| 8 | FMC2 (upper) | 70.0 |
| 9 | FMC1 (lower) | 64.7 |
| 9 | FMC2 (upper) | 73.6 |
| 10 | FMC1 (lower) | 60.8 |
| 10 | FMC2 (upper) | 71.0 |
| 11 | FMC1 (lower) | 52.4 |
| 11 | FMC2 (upper) | 59.2 |
| 12 | FMC1 (lower) | 40.2 |
| 12 | FMC2 (upper) | 51.6 |
Conclusions*
- Cards in the middle slots (8-10) are the worst (25 degC difference
over slots 7 and 12). Uneven air flow in the crate?
- FMC1 is approximately 8-10 degrees cooler than FMC2.