[net.micro.mac] Cooling Fan Comparison

morse@leadsv.UUCP (Terry Morse) (11/16/85)

This is a comparison of two cooling fan/surge suppressors for the MAC.

			Fanny Mac		MacBCool
________________________________________________________________________

Airflow			24 CFM			17/20 CFM
Noise level		30 db @ 1 meter		2/13 db @ 3 ft
Transient protection	MOV			MOV
Clipping Voltage	 ?			200 V
Max. Clamping voltage	395 V @ 50 A^(-6)	?
Peak Current		4500 A @ 8/20 sec^(-6)	6500 A @ 20 sec^(-6) max
Peak Energy		45 J @ 10/1000 A^(-6)	70 J
# of outlets		1			3
EMI Filter		no			yes
Sugg. Retail		$125			$169
Company			Beck-Tech		MPH Electronics
			41 Tunnel Rd.		2660 Loma Ave.
			Berkeley, CA		South El Monte, CA

These figures have been taken directly from their literature.  MacBCool
covers the entire top of the Mac, whereas Fanny Mac slips into the Mac's
handle recess.

Another thing to ponder: (from Office Computing, June 3, 1985)

"If you decide to buy a [surge] protector, it's best to look for units
that can handle:
	(1) Power drops.  The unit should be able ... to shut off the
	power if the voltage drops below 20% of normal.

	(2) Power surges ...

	(3) Power filtering.  The unit should be able to filter out
	noise from 150 kilihertz to 30 megahertz, and to -50db."

Why are power drops so dangerous to circuitry?  Neither MacBCool nor Fanny Mac
have any protection for power drops.  Could someone explain if it is something
we need to be worried about?

Note: The above referenced article recommended either the Powersafe or Ultramax
surge supressors ($90 and $80, respectively).  The article was written for the
Stanford Workstation Support Center.
-- 

Terry Morse  (408)743-1487
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