Carlos E. R. wrote:
The Thursday 2008-02-14 at 10:19 -0800, John Andersen wrote:
Even the cheapest of the cheap powersupplies can handle spikes of the duration you mention. In fact these are designed to supply of capacity tp park heads on disk drives in the event of a total power failure, and this extra capacity is available to handle spikes.
Actually, voice coil type heads park with no power at all. With no current the spring takes the heads to the park position automatically. What you say was true for stepper motor type heads, which have been out of use in PCs for... perhaps 20 years.
Actually, the drives are designed so that the heads can land safely in the data area and so there's no need for such a spring. A few years ago, I pulled the cover off a drive and I don't recall any spring pulling the heads back in it. On the other hand, the old disk pack drives certainly had a retract mechanism, consisting of a large capacitor and a relay that would connect it to the linear motor, in the event of a power failure. -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org