On Jun 24, 2:35 pm, Rich Webb <bbew...@[EMAIL PROTECTED]
> wrote:
> On Tue, 24 Jun 2008 10:42:34 +0200, NoSp <N...@[EMAIL PROTECTED]
> wrote:
> >Should I connect something like a caramic capacitor across each of the
> >relay's switch connections? Which capacitance values are we talking?
>
> Just swagging this: The 12 V shouldn't care; the drive motor isn't spun
> until after the drive electronics start up. On the 5 V rail, it looks
> like a typical modern drive initially pulls about 300 mA. Hand-waving a
> power interrupt time during contact bounce at around 1 ms, to hold the
> droop on 5 V to < 10% would require about 600 uF.
So a 600uF ceramic capacitor (or similar) across the 5V switched lines
of the relay?
Sounds good.
Something else comes to mind. Since I'll have two separate on/off
switches there is a chance that I may power up the enclosure without
putting much load on the power supply. I've heard that this is a bad
thing for switched mode power supplies.
The dual-SATA to Firewire/USB bridge board will of course be directly
connected to the PSU, so when I flip the enclosure's power switch
it'll draw some power (I'm not sure how much, but I do know that it
only uses the +5V line, which leaves the +12V line unused).
I do however plan to put a fan inside the enclosure, but through some
sort of temperature controlling circuitry so as to keep the noise
level down, so I don't know how this will affect the PSU.
Is this something I should be concerned about?
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