On 26 May 98 at 22:20, Art Sauder wrote:

> Just started assembling my first machine and was wondering if
> someone could clue me in on the meaning of "momentary" vs
> "permanent" as they refer to power switches. I have an ATX case and
> am putting a Shuttle HOt 603 in it. I am trying to figure out which
> connectors on the mainboard to plug the power s/w on the front of
> the case to. There are two connectors on the mobo, one is for a
> "permanent" switch and the other for a "momentary" switch.

  I have this board, currently in an AT case.

  A "momentary" switch is like a push-button; contact is made only
briefly, while the switch is held, and it springs back when released.
This is the standard arrangement specified by ATX.  Each time the
power switch/button is pressed, the power alternates between "ON" and
"OFF".
  Most AT cases provide a power switch with two *positions*, ON and
OFF.  [I've never seen "permanent" used to describe such a switch; in
electrical terminology, this is the default and "momentary" is an
exception.]

  The HOT-603 is designed to work in either sort of case, AT or ATX,
and provides power connectors for either sort of power supply.  In
the standard AT case, the case power switch connects to the power
supply.  In the standard ATX case, the case (momentary) power switch
connects to the motherboard.
  Since this board has an AT layout, but also has an ATX power
connector, you *could* mount it in an AT case, but install an ATX
power supply.  In that case, you'd connect the case power SWITCH to
the "non-momentary switch" pins on the motherboard, which will in
turn control the ATX power supply appropriately.

  Since you have an ATX case, the case power switch will be
momentary.

David G