Introduction - If you have any usage issues, please Google them yourself
Answer the number is controlled by the main circuit and the expansion of circuit components. Priority encoder circuit, latch, decoder circuit will be teams of the input signal in the display output with control circuitry and the host switch alarm circuits, and above the main circuit is composed of two parts. Through the timing circuit and decoding circuit to generate pulse signals in the display output timing functions, constitute the expansion of the circuit. After wiring, welding, debugging, etc. Answer device forming after the figures.