Front Panel Switches

[mojo1340]

I want to build a cool machine for my wife for Christmas. I'm stumped on the power and reset switches. Are these just ordinary momentary switches or is there something "special" I'm unaware of?

Any pointers on types or vendors appreciated.

TIA

[Gizmo]

SPST N/O momentary. Nothing fancy.

[mojo1340]

Thanks, Gizmo!

[cadaveca]

aren't they just a single pull double throw...or is that the same thing...jargon is not my speciality.. that's my roommates

[Aedan]

SPST is single pole single throw. The single pole just means there's only one set of contacts. The single throw means the contact is either open or closed.

[Gizmo]

Single Pole means you can only switch one circuit.
Double Pole means you can switch two ciruits. I have seen switches with up to 6 poles, and there are heavy-duty industrial switches with as many as 20 poles.

Single Throw means that you basically have a make/break switch. In one position the circuit is closed, in the other position, the ciruit is open. This is like your basic On/Off switch. You have two connections for each pole of the switch, so an SPST switch will have only two connections.
Double Throw means that you have a switch that can make a connection from two different circuits to a common circuit. You have three connections for each pole, with the center connection being the common (usually), so an SPDT switch will have three connections, and a DPDT switch will have six connections.

N/C or Normally Closed means that when the switch is in its default or idle state, the contacts are closed, so you activate the switch to break the circuit.
N/O or Normally Open means that when the switch is in its default or idle state, the contacts are open, so you activate the switch to make the circuit.

For Single Throw switches, the N/C and N/O nomenclature is pretty straight-forward. For Double Throw switches, one set of contacts will be N/O and the other set will be N/C.

Note that you can also have Triple Throw and Quad Throw switches. These are normally implemented as slide switches. For anything beyond this, you will have a 'selector' rather like the channel selector on old, OLD television sets.

[cadaveca]

my thing is this..i get a switch...it pops back out when i push the button, but things stay on...
on the otherhand, my light switch must remain depressed for the light to stay on....what's the differnce..?
i just wanna wire an switch to a 2nd psu so i can turn it on and off at will without a mobo, and as far as i understand it bittons that pop back out are single pull double throw.

[Gizmo]

Buttons that pop back out can be a lot of things. But since we are talking about a computer in specific, let's restrict our discussion to that in order to simplify things.

The power switch on the front of your computer is a single pole single throw switch, with normally open contacts and a momentary action (means it is only active as long as you press it).

The mobo has an internal register that toggles every time the power switch is pressed. So the first time you press the switch, the internal register toggles on. The second time you press the switch, the internal register toggles off. This is tied to the PSU, so making the computer come on and stay on, or go off and stay off.

You can also get switches that are made to latch this way as well. They are refered to as 'latching' or 'push-push' switches instead of momentary switches.

For what you want to do, you should get a single pole, double throw switch. Although this will have three connections, you will only wire two of them up. This will effectively create a latching single pole single throw switch, which is what you want.

[cadaveca]

thanks for the heads up.
lol i forgot that there was a mobo between the switch and the psu