Abstract : This Project defines a digital stop watch built around timer IC LM555 and 4-digit counter IC MM74C926 with multiplexed 7-segment LED display.
MM74C926 consists of a 4-digit counter, an internal output latch, npn output sourcing drivers for common cathode,7-segment display and an internal multiplexing circuitry with four multiplexing outputs.
The counter advances on negative edge of the clock. The clock is generated by timer IC LM555.The circuit works off a 5V power supply.
It can be easily assembled on a general-purpose PCB. Enclose the circuit in a metal boxvwith provisions for four 7-segment displays, rotary switch S1, tart/stop switch S2 and reset switch S3.
Please find the following attachments"Digital Stop Watch seminar report/pdf/ppt download" here.........