Coolit is Varo's 'Early Warning System', pinpointing thermal and
airflow problems so that our electronics designers can make quick
circuit improvements. Under a recent contract to Lockheed-Martin, Coolit
helped us develop a digital power supply for the Apache helicopter's
Arrowhead Project, a fully modernized night vision and target acquisition
system. The very small power supply modules provided highly precise
The design consisted primarily of a finned heat sink with two high-density
printed circuit boards mounted on each side. In this unit, both the overall heat of
each board and the specific heat generated by hot spot components
presented thermal challenges.
The only way to get the thermal information we needed in our limited timeframe
was to acquire CFD analysis capabilities. We reviewed our
CFD options and selected Coolit. It took less than 4 hours to load the
software, run the tutorials, perform some test simulations and then begin
running actual design scenarios. In the next 4 hours, we had information
we could use.
With Coolit, we were able to quickly characterize a fin design that would
remove heat from the boards and into the customer's specified airflow. The
highest risk components for hot spots were the FET drivers, which are small,
SO packages with moderate thermal dissipation, but with a high, 40C/W,
junction to case resistance. Our electrical and mechanical engineers both
had pre-conceived notions as to which chips would give us thermal problems.
Coolit simulations quickly revealed hidden risks, enabling our
mechanical engineers to pinpoint the problem chips. Once they were
identified, the electrical engineers solved many problems by re-design,
splitting a thermal load so that part of it would go to a remotely located
resistor instead of having the driver chip handle it all.
Coolit proved so easy-to-use that it shortened our thermal analysis cycle
significantly and probably saved us from hiring an extra thermal engineer.
It became obvious to us that Coolit had been seamlessly designed by engineers
who do this type of analyses regularly. Furthermore, Coolit was priced lower
than the competition and offered impressive stability. Our previous experience
with other software has been that crashing is a daily ritual.
Throughout the project, we had access to Coolit's excellent technical support.
Phone calls were answered by a real person, not a recording, and emailed
questions received a response within 2 hours.
We found Coolit's free viewer, CoolPlot offered an excellent way to share
computed results with our customers. CoolPlot was sent to the customers who
accessed case files placed on an FTP site. The customers could view any of the
Coolit simulations and provide early feedback without purchasing any software