All, I cannot remember all of the equations that go into this, and only a very simplistic approach follows, but ... If your surge protector is a semi-conductor, it probably will be self-limiting. That is, it will reach a maximum block, and pass whatever is above that. A Trans-sorb device, and those chemical ones, all limit what they do based upon a total absorption. A lot of little ones kills it the same as a single big one. None of these tell you they are no longer operable. However, if the UPS is properly built, it will have an inductor as the leading serial device in a set of 'things'. I would expect a set of capacitors, in parallel with my load, on either side, appropriately sized. The battery that makes the 'U' in the UPS acts like another capacitor. These act as fast as the spike, ALWAYS. The sizes and number of components requires some calculations (testing does NOT hurt, either). Stan needs to review his basic electronics. Yes, it will even protect against lighting if designed for that purpose. Costs vary accordingly ... Bob De Witt, rdew@el.nec.com The views expressed herein are my own, and are not attributable to any other source, be it employer, friend or foe.
From StanSquncr@aol.com Wed Mar 18 22:44:02 1998 From: StanSquncr <StanSquncr@aol.com> Date: Thu, 19 Mar 1998 00:59:19 EST To: spectre@anthrax.net, cypherpunks@toad.com Mime-Version: 1.0 Subject: Re: UPSs Content-transfer-encoding: 7bit
In a message dated 98-03-18 23:54:33 EST, spectre@anthrax.net writes:
<< ... Any decent ups will put the incoming power through a "conditioner" that will filter out noise in the incoming power, and rebuild the wave so that transient sags and spikes don't get through. ...
BUT, even the fastest electronics cannot respond fast enough to the initial spike, if that spike is too high in the first place (if your incoming power lines get hit by lightning, for instance), it's already too late. My suggestion, don't trust a UPS to eliminate spikes, get it if you anticipate a need for back-up power to shut down your system in case of black-out (and screw the surge protectors, trust the filtering in your power supply to do that for you.)
Stan