What is gate circuit and how to judge it's good or bad?

1. Gate circuit.

The unit circuit which is used to realize basic logic operation and compound logic operation is called gate circuit and is represented by the letter U. There are several kinds of gate circuits in common use, such as phase inverter (non-gate), and gate, and-non-gate,or-gate, or-non-gate.

When the gate specifies that a logical relationship is satisfied between each signal input, the output end will have the signal output. There are only two states from the logic relation, no signal is expressed as "0" and there is signal as "1".

Since the existing gate circuits on the main board are basically integrated in the Nanqiao chip and the 1O chip, only the symbols and logic relations of the gate circuits are introduced here.

2. A phase follower. The circuit symbol, as shown in figure 1, has an input and an output, A as the input and Y as the output, and the output is equivalent to the input. When A inputs high levels, Y outputs high levels. And A input low power, Y output low level. There are 7407,LVCO7 and HCTO7 in the main board, and 6 in-phase devices are integrated (see figure 2).

       （a）Circuit symbol            （b）Logical relation table

      Fig.1 The symbol and Logic relation of the Circuit in the same Phase device

         （a）Physical picture        （b）Pin definition

        Fig.2    7407 definition of physical object and pin of phase apparatus

 3.The good or bad judgment of the gate circuit.

After power on, the relationship between input and output of gate circuit is measured, and then compared with logical relation table. Those that conform to logical relational tables are good, and those that do not conform to logical relational tables are bad. Gate damage can be replaced with the same type of gate.

              Fig.3 Gate circuit composed of discrete elements

 If you want to know more, our website has product specifications for gate circuits, you can go to ALLICDATA ELECTRONICS LIMITED to get more information