Tektronix TLA7XM, Manual, Page: 37 / 190

Specifications
1- 12
TLA721 Benchtop & TLA7XM Expansion Mainframe Service Manual
Table 1- 8: Benchtop and expansion mainframe cooling
Characteristic Description
Cooling system Forced air circulation system (positive pressurization) using a single low-noise
centripetal (squirrel cage) fan configuration with no filters for the power supply and 13
module slots.
Fan speed control Rear panel switch selects between full speed and variable speed. Slot exhaust
temperature and ambient air temperature are monitored such that a constant delta
temperature is maintained.
Slot activation Installing a module activates the cooling for the corresponding occupied slots by opening
the air flow shutter mechanism. Optimizes cooling efficiency by only applying airflow to
modules that are installed.
Pressurization Positive pressurization system, all chambers including modules
Slot airflow direction P2 to P1, bottom of module to top of module
Mainframe air intake Lower fan-pack rear face and bottom
Mainframe air exhaust Top-sides and top-rear back. Top rear-back exhaust redirected to the sides by the fan
pack housing to minimize reentry into the intake.
∆
Temperature readout sensitivity 100 mV/
°
C with 0
°
C corresponding to 0 V output
Temperature sense range --10
°
C to +90
°
C, delta temperature
≤
50
°
C
Clearance 2 in (51 mm), rear, top, and sides
Fan speed readout RPM = 20
¢
(Tach frequency) or 10 (+Pulse Width)
where (+Pulse Width) is the positive width of the TACH1 fan output signal measured
in seconds
Fan speed range 650 to 2250 RPM