what's the difference between SPST and SPDT... and DPST...DPDT?

[Walleye]

i understand spst is single pole single throw. i'm guessing spdt is single pole dual throw..... i'm guessing DPST is dual pole single throw, and so on for DPDT...

but, what is the difference? and what would i need to turn on a computer?

 

[Walleye]

i'm hoping to buy these switches tonight, or tomorrow at radio shack... any help would really be appreciated...

 

[Walleye]

um.. yeah.. thanks...

 

[Colt45]

you need a NO pushbutton to turn on an ATX PSU.

if you want a switch on the 120v line, you need a SPST

err wiat a second. might need a SPST to turn on a ATX. i forget if it needs power just for an instant to turn on, or steady-state.. :-/

bleh

 

[Walleye]

Originally posted by: Colt45
you need a NO pushbutton to turn on an ATX PSU.

if you want a switch on the 120v line, you need a SPST

what is NO?

would a momentary pushbutton work?

EDIT: the switch is to turn on and off a power inverter in the car... i figure if i just break the line, it breaks the power. the pushbutton is for turning on and off the computer.

 

[Colt45]

yeah, NO - normally open

 

[dighn]

Originally posted by: Walleye
i understand spst is single pole single throw. i'm guessing spdt is single pole dual throw..... i'm guessing DPST is dual pole single throw, and so on for DPDT...

but, what is the difference? and what would i need to turn on a computer?

spst has 2 connectors, either open or closed
spdt has 3 connectors, the middle connector is either connected with one of the other connectors or the other

dp*t is just two of those together

atx i think you just need a push button

 

[Walleye]

Originally posted by: Colt45
yeah, NO - normally open

alright, thanks. just making sure, i can run any guage cable, right?

 

[Monel Funkawitz]

Here is a pic I drew for ya.

Link

Basically....

SPST - Turns one thing on or off.
SPDT - Connects to two things. Both cannot be on at the same exact time.
DPST - Turns two things on or off at the same time.
DPDT - Same as two SPDT side by side.

 

[Walleye]

Originally posted by: Monel Funkawitz
Here is a pic I drew for ya.

Link

Basically....

SPST - Turns one thing on or off.
SPDT - Connects to two things. Both cannot be on at the same exact time.
DPST - Turns two things on or off at the same time.
DPDT - Same as two SPDT side by side.

thanks a lot. that explains it

sometimes, there's nothing like a picture


alright... so i only need a spst and a pushbutton.


now, to decide on aesthetics... :Q