I remember reading on howstuffworks.com (specifically, their article about how to build your own digital clock) that all homes' power lines have a 60Hz signal. If a 60Hz signal goes into a power supply, does a 60Hz signal come out?
 
I'm curious about this because there's a chip called a "counter" that is used in the digital clock article. The counter counts from 1 to 10, stepping up once for every oscillation. (Hz == Oscillations per second.)
 
If someone were to build a clock like in that article ( http://www.howstuffworks.com/digital-clock.htm ), would it be possible to use the PC's power supply as the clock's power supply and to mod a PC case to put the clock in it?
 
I know this is currently beyond my abilities. But I'd like to try it someday, and I need to know if the outputted Hz of a power supply can be counted on.