1 AND gate
And: it means simultaneous, a and b or more conditions. Only when you have it at the same time can you have a result. As long as one condition is not met, there will be no result.
Only when both switches are closed will the light come on, that is, the two switches are connected in series.
2, or door
Or: or it means many conditions a, b, c, etc. When at least one of them is met, there will be a result, and only when all the conditions are not met will there be a result.
Just close one switch and the light will come on, that is, the two switches are connected in parallel.
3. Not a door
No: It means the opposite. For condition a, there is no result. Without condition a, there is a result.
Only when the switch is turned off will the light come on, that is, there is a switch in parallel with the light.
4. NAND gate and NOR gate can be seen from their names that they are the combination of the above three gate circuits, that is, the corresponding two circuits are connected in series.
5. Gate circuits are mainly used in digital circuits. The opening and closing of the switch are marked as "0" and "1", so there will be a set of combinations of 0, 1, which is called truth table.
Gating circuit
1, definition: the unit circuit used to realize basic logic operation and compound logic operation is called gate circuit. Commonly used gate circuits have several logical functions, such as AND gate, OR gate, NOT gate, NAND gate, NOR gate, NOR gate and XOR gate.
2. Nature
Gate input: A "gate" is a circuit that specifies that signals can only be output when a certain logical relationship is satisfied between input signals. There are usually three kinds of gate circuits: AND gate, or NAND gate (inverter). From the logical relationship, the input or output of the gate circuit has only two states, no signal is represented by "0" and a signal is represented by "1". You can also specify that the low level is "0" and the high level is "1", which is called positive logic. Conversely, if the high level is "0" and the low level is "1", it is called negative logic. But high and low are relative, so it is practical to explain what logic is used in the actual circuit first. For example, the negative AND gate has an AND relationship for "1", but for "0". Similarly, the negative OR gate has an OR relationship with "1", but has an AND relationship with "0", that is, the negative OR gate is also a positive AND gate.
Basic logic circuit: any electronic circuit that switches pulses on the pulse path is called gate circuit, which is a basic logic circuit. A gate circuit can have one or more inputs, but only one output. Only when the pulse signals applied to the input terminals of the gate circuit meet certain conditions, the "gate" will be opened, that is, the pulse signals will be output. Logically speaking, it is the "cause" of the input meeting certain conditions and the "result" of the signal output. The function of gate circuit is to realize some causal relationship-logical relationship. So gate circuit is a kind of logic circuit. There are three basic logical relationships: and logic, or logic and illogical. Correspondingly, the basic gate circuit is AND gate or NAND gate.
(Source: Baidu Encyclopedia: Gate)