Uses 8 operational amplifiers to represent the voltage level of the input signal (0 to 4.5 volts).
The max voltage of 4.5 V is placed across a series of resistors to create an 8 element voltage divider. These voltage levels, along with the input signal (in this case a simple some wave), are fed to 8 op-amps in comparator configuration in order to light each LED when a certain voltage level is reached.
