Seven Segment LED Display Circuit

A common anode seven segment module is fitted on a board with 8 bit dip switch to control the each segment of seven segment LED display. The inputs A-D of a display driver are connected to the binary coded decimal (BCD) outputs from a decade counter. A network of logic gates inside the display driver makes its outputs a-g become high or low as appropriate to light the required segments a-g of a seven segment display. A resistor is required in series with each segment to protect the LEDs