The current from a battery flows in the
same direction all the time and the amount of current does not change so
long as the resistance of the circuite is constant. These are called
Direct Current, or DC. A battery is a DC voltage source. The mains
supply is AC or Alternating current. How does it vary with time. An easy
way to compare the two is plotting the voltage as a function of time.
The PVS output of expEYES is a DC source, and the SINE output is an AC
source. Connect PVS to A1 and SINE to A2 and watch them using the CRO+
program. The peak voltage of our AC is 3.73 volts and the frequency is
151.5 Hz. For the mains supply voltages are in hundreds of volts and the
frequency is either 50 or 60 Hz.