DTL AND gate
DTL can also be used in AND gates, as we'll see in this Project. You'll find it works just like other AND circuits we've played with in the past.
When you finish the wiring connections, put the power ON. You'll find that LED 1 will not light until both the Key is pressed and the Select Switch is set to A. Can you tell how this Project works by looking at the schematic?
At first glance it may seem like the circuit for this Project and our last one are virtually identical can you spot the differences?
(Okay here's a clue - which way is the arrow pointing?).
It's also possible to make up an AND gate using just two diodes and a resistor. Can you figure out how? Be sure to make a note of what you come up with and compare it with our schematic.