Window detector

Sometimes one may like to mark the instant at which an unknown input is between two threshold levels.This can be achieved by a circuit called window detector.The circuit consist of a three level detector with indicator circuit .There are 3 indicators:YELLOW LED(turns ON for too low input (<3V)),GREEN LED (turns ON for safe input(3--6V))and RED LED (turns ON for high input (>6V)).They are turned ON and OFF as indicated as follows: ----------------------------------------------------------------------------------------------------------------- INPUT(Volts) YELLOW LED 3 GREEN LED 2 RED LED 1 ----------------------------------------------------------------------------------------------------------------- Less than 3V. ON OFF OFF ----------------------------------------------------------------------------------------------------------------- Between 3V and 6V. OFF ON OFF ----------------------------------------------------------------------------------------------------------------- Greater than 6V. OFF OFF ON ----------------------------------------------------------------------------------------------------------------- INPUT is indicated in BLUE wire in this circuit. Change the input and LED glows according to your input. MY QUESTION: Eventhough the circuit works there is no indicator for lnput (3V) and Input (6V).For these inputs all LEDs are in OFF condition.So how to differentiate or identify these two inputs in the circuit?What changes should be made in the circuit so the led will indicate 3V and 6V input? PLEASE ANSWER .

published 9 years ago