How to use pull up/pull down resistors ?

Till now you might have understood about the pull up/pull down resistors and why we need them in our digital circuits.

First one we took is pull up resistors. Here you can see in image a) (i) that two resistors are connected at the input of logic device in series with 5Volt Vcc.

And by default it is “HIGH” or “1” when switch is open. And in this way logic device gets proper defined value to operate.

And now you can see in image a) (ii) that two resistors are connected at the input of logic device in series with 5Volt Vcc.

After the switch is pressed the Vcc gets short to ground and default state i.e. “HIGH” or “1” goes to “LOW” or “0” state. And in this way logic device gets proper defined value to operate.