NAND gates need all inputs to be high in order for the output to be low. If any or all inputs are low, then the output is high. The NAND gate is the opposite of the AND gate where the output is only high if all inputs are high.
The 74xx00 version of the 7400 series of integrated circuits, is the 2 input Quad (4) NAND gate. The most common version being the high speed CMOS (HC).
This demonstration circuit isn’t a practical circuit but it helps to understand the 74HC00 IC and it’s limitations.
When the output is low (close to 0V) then current will flow from +5V through the blue LED to ground. The blue LED will light up.
Whereas, when the output is high (close to 5V). Then current will flow from the output to groung through the red LED. The red LED will light up.
Other circuits may have a different voltage for high and low, and may use different terminology that are more relatable to the type pf circuit that it is.
I recommend getting a kit with a bunch of different 74HCxx versions of the 7400 series ICs to practice building circuits. 2 kits is a god idea if there is only 1 of each IC. They fry somewhat easily from human body static discharge and miswirings. Related affiliate link ads are shown below.
Links to good topics to check out next.
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