On the popular seven-segment ****yang LED display, the display of the public **** terminal connected to the 5V power supply, the segments through the 1k current-limiting resistor connected to the output of the seven-segment decoder. The attached figure is a seven-segment ****yang LED display and 74LS47-type display decoder of the two connection circuit.

Because the computer output is BCD code, in order to display the decimal number on the digital tube, it is necessary to first convert the BCD code into the code required by the seven-segment word type digital tube.

The circuit that converts the BCD code output from the computer into a 7-segment alphanumeric code and displays a decimal number on the digital tube is called a "7-segment alphanumeric decoder".

Expanded information:

(a) is the **** anode connection, which is the seven light-emitting diode The anode of the seven light-emitting diodes is connected together as the male **** terminal, when used to connect a high level. The cathodes of the LEDs are connected to the corresponding outputs of the seven-segment decoder through current-limiting resistors with valid low-level outputs.

(b) shows *** cathode connection, it is the cathode of seven light-emitting diodes connected together as a public **** terminal, when used to connect a low level. The anode of the light-emitting diode is connected to the corresponding output of the seven-segment decoder through a current-limiting resistor that outputs a valid high level. Changing the resistance value of the current limiting resistor can change the size of the current of the light-emitting diode, thereby controlling the luminous brightness of the display.