TTL line selector
Électronique / Electronic
It isn't too hard Lo think of situations where we might want to send input data to two or more different outputs.
This Project shows how we can use a network of NAND gates to help us do just that. You can see that we use a multivibrator and three NAND gates in this circuit.
You can leave the Select Switch at either A or B when building this Project.
When you put power ON, you'll see that LED 1 is blinking. But what are LED 2 and LED 3 doing?
If the Select Switch is at A, LED 2 is blinking. But if the Select Switch is at B, LED 3 will blink.
As you can see on the schematic, setting the Select Switch to A or B controls the inputs to the two NANDs that light LED 2 or LED 3.
With the Select Switch at A, the NAND controlling LED 2 gets one steady input of 1. The output of the multivibrator supplies the other input. As the multivibrator's output switches from 0 to 1, the NAND controlling LED 2 also switches its output from 0 to 1.
The opposite happens when you set the Select Switch to B, Now the NAND controlling LED 3 gets a steady input of 1 so that LED 3 can go on and off according to the input from the multivibrator.
Now put on your thinking cap and try to follow the inputs from A and B of the Select Switch to LED 2 and LED 3. Notice the NAND gate serving as an input for the NAND controlling LED 3 what happens to it when you set the Select Switch from A to B?