hey there.. I was asked to design a circuit using multisim software of a solar panel tester.. I know I need an operational amplifier.. a diode pehaps.. but I don't have a background concerning the way operational amplifiers work... The lecturer wants us to construct this kind of circuit: "The Tester consists of four levels of LEDs voltage display, Red, Orange, Yellow and Green. 1. The tester will show all the LEDs lighting up when the voltage of the Solar Panel is 6V. 2. When the voltage of the Solar Panel is 5V, the Red, Orange and Yellow LEDs will light up. 3. When the voltage of the Solar Panel is 4V the Red and Orange LEDs will light up. 4. When the voltage of the Solar Panel is 3V, only the Red LED will light up. 5. When the voltage of the Solar Panel is less than 3V no LED will light up." I don't know where to start..I can't find till now useful information to helpme construct such a circuit on multisim... can ne1 help by atleast giving me the way to start?