24/ twenty-square counter

Photocoupler

Below is the circuit diagram of a 24-square counter. This type of counter can be constructed based on a hexadecimal system by using a feedback zeroing method. The counting range is from 0 to 23, with 24 acting as a transitional state. When the higher bit reaches 2 and the lower bit reaches 4, the counter resets to zero.

To implement this, Q20 and Q11 are directly connected to R0A and R0B, forming a quaternary counter. This configuration ensures that the counter cycles correctly within the desired range. The circuit design is illustrated in Figure 12.9, which provides a clear visual representation of how the components are interconnected to achieve the intended functionality.

This approach is commonly used in digital electronics for designing counters with specific ranges. Understanding how to use feedback mechanisms allows engineers to customize counters for various applications, such as timing circuits, frequency dividers, or control systems. By carefully selecting the feedback points, you can adjust the count cycle precisely, ensuring accurate and reliable operation in real-world scenarios.