On Mon, 23 Jun 2008 12:50:11 +0200, NoSp <NoSp@[EMAIL PROTECTED]
> wrote:
>Do latched relays in general "wiggle" back and forth (if even for a
>fraction of a second), or do they work as a firm and precise on/off
switch?
Relay contacts will bounce, although not so much that they go all the
way back to the opposite state. Google for "relay contact bounce" to
turn up lots of discussions on this. Even firm, precise on/off switches
can bounce.
>I'm planning to cut/supply power to an external SATA hard drive by
>having the +12V and +5V lines through a relay (dual pole), controlled by
>a momentary push-button. But if the relay "wiggles" from one position to
>another when activated I'm worried that this will in the long run harm
>the drive (from what I've been told it's harmful to most electronic
>devices if you switch it on-off-on-off... quickly), so like a mechanical
>switch I want it to be in either a definite on or off position when I
>activate it.
You should be fine. You could add some capacitance to the power lines to
smooth over the bounces but be aware that slowly rising power can also
cause some circuits to mis-behave so don't go overboard on monster caps.
--
Rich Webb Norfolk, VA
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