It is very difficult to keep track of number of balls and number of overs bowled simultaneously so in order to solve this problem we built a small Cricket Over Counter which keeps track of no balls and no of overs bowled.Whenever the legal ball is bowled the switch is pressed and it reminds when one over is completed.The circuit operation is simple – after each ball has been bowled, the scorer presses switch S2, which sends a negative going pulse to the trigger input, pin 2, of CMOS timer IC1, triggering it for a period determined by the values of components R3 and C2.
The resulting positive output from IC1 pin 3 triggers the inputs of decade counters IC2 and IC3. It also enables all the 7-segment common cathode l.e.d. displays until the timing period is over, thus conserving battery power (i.e. the displays will show the ball and over count for a few seconds after S2 has been pressed, before turning off. IC2 counts the balls and then resets itself, and IC3, when output Q7 goes high when the sixth ball is reached.
The solid-state buzzer WD1 is simultaneously also turned on, via transistor TR1, signalling the end of the over. It remains sounding for the same duration as the display is on. The balls display is returned to zero and the reset pulse clocks counter IC4, ensuring that the l.e.d. units display advances by one digit. When the tenth over is reached, counter IC5 receives a carry-out pulse from IC4 and therefore the tens display advances by one digit and so forth. A maximum of 99·5 overs can be counted. An extra display stage could be added for a greater number of overs. No reset switch is included – resetting can be achieved by switching the unit off and then on again, after a brief delay to allow capacitor C4 to discharge completely. A good quality switch must be used for S2.