Using a NAND Gate for a Set/Reset Latch
One easy way to create debounced and latched input is to use cross connected NAND gates to create a set/reset latch. Here is a circuit for 2 bits:
Here is the fig diagram. For more info on the program that created the schematic, see Xfig.org.
Here is how the circuit looks when breadboarded:
This is also a very simple memory. Really, memory is just a way to latch bits, which this circuit does. The 74hc00 can source 4 mA, according to the data sheet, and so a 1K resister with a 5 volt VCC is fine. The LEDs light up well. To use, just push one of the pair of buttons for off, and the other one for on. Using these tiny switches is much cheaper than toggle switches.
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