Pushbutton (or momentary) switch

A pushbutton switch is like any other switch; it needs to be used with a resistor to provide input to a logic gate. They are momentary; i.e. they are only connected as long as the button is held down.



These switches are handy because the pins will fit in a breadboard.



An alternative version looks like this:



You can use a switch with either a "pull-up" resistor or a "pull-down" resistor, depending on whether you want the signal to be high or low when the button is unpressed.



Here is a switch with a pull-up resistor. (The signal is the yellow wire.):



Here's the alternative type (The signal is the blue wire.):



Here is a switch with a pull-down resistor. (The signal is the yellow wire.):



Here's the alternative type (The signal is the blue wire.):



Note that in each case, the output comes from the place where the resistor and switch connect. ( In other words, from the same row of the breadboard as the resistor.)

Here's a schematic of the connections, which may make it easier to visualize:



Rotating the figure for the other type makes it easy to see the same setup. The blue wire is the signal. (It's reversed, left to right.):