
Digital Logic | 3.3
Electric Circuit for OR gate: Circuit is given in Figure 3.2. Switches act as inputs. Output of
circuit is operation of Lamp.
• When both the switches A and B are open (OFF) (i.e. A = 0, B = 0), the lamp does not
glow (X = 0).
• When switch A is closed (ON) and switch B is open (OFF) (i.e. A = 1, B = 0), the lamp
glows (X = 1).
• If switch A is open (OFF) and switch B is closed (ON), (i.e. A = 0, B = 1), the lamp
glows (X = 1).
• If both the switches A and B are closed (ON), (i.e. A = 1. B = 1), the lamp glows (X = 1).
• It is concluded, if any one switch is ON, the lamp glows.
OR Gate Using Diode: Circuit is given in Figure ...