CompactPCI ‘Cool Box’ subrack has active ventilation
Cool Box from SMA Computers has 4U height that allows for airflow routing and provides space for CD/DVD drives. A ruggedized hard-disk drive with vibration absorber also can be installed in that space for other applications.
Rising performance demands on industrial-grade computer systems involve ever-increasing clock frequencies for the associated processors. In turn, higher clock frequency means more power dissipation and heat to be removed from the system to ensure proper operation. With this in mind, SMA Computers offers a standard, ventilated CompactPCI subrack—called Cool Box—to meet new dependability levels for various applications.
SMA Computers cautions users to look closely at “fanless systems” specs. This technology promises to increase system MTBF (mean time between failure) by eliminating the fan, but increased operating temperatures in the electronics modules may offset the effect, if the system is not properly designed, according to SMA. Heat greatly affects the service life of electronic components; for example, an ambient temperature rise of 10 °C doubles failure rate of components. “An engineer should make every effort to adequately design the ventilation of the industrial computer system. This applies particularly to systems for use in extended temperature ranges or where computing power from the CPU might climb to 100%,” says SMA.
This is where Cool Box can enter the picture. Its standard version includes a small 4U/36 HP CompactPCI subrack, providing space for a 3U, 8 HP CPU, and five I/O modules, which can handle numerous standard applications. Several low-cost 8 HP plug-in power supplies (ac or dc) are available as well. Cool Box includes a rear fan with filter. Since industrial computer modules are ventilated from the bottom up by a cooling air stream via an internal air deflector, Cool Box can be installed without clearance underneath it. Cool Box is priced from $1,800 each.
Frank J. Bartos, Control Engineering,