Quick question on AC

[thoughtgaze]

So if my input is an alternating voltage source, some sort of function generator plugged into the wall... will it oscillate around ground or will it oscillate above ground? Hope this question makes sense.

 

[berkeman]

So if my input is an alternating voltage source, some sort of function generator plugged into the wall... will it oscillate around ground or will it oscillate above ground? Hope this question makes sense.

Depends on the source. Most lab function generators let you specify Amplitude, Frequency, and DC Offset.

 

[waht]

It's very likely that the signal generator will be grounded, if so then the signal will oscillate above and below the ground.

 

[vk6kro]

A signal generator will produce sine and square waves that are centered at ground and vary equally on either side of ground.

A function generator can do this too, but it can also generate logic pulses that vary from zero volts (ground) to some figure like plus 5 volts, which you can preset.
These pulses have the right voltage to drive logic circuitry for testing purposes.