Digital Ping Pong Circuit

Figure 1 

The objective of the circuit is to create a ping pong game from a digital circuit that would provide the significance of up and down ball movement.

• Ping Pong – a sport that represents another term for table tennis in which two or four players are hitting a hollow, lightweight back and forth using rackets or paddles, where the game takes place on a hard table divided by the net
• 74193 – a synchronous up/down 4-bit (0-15) counter with outputs that change precisely together on each clock pulse where the count increases as the up clock input becomes high and the count decreases as the down clock input becomes high but the count resets to zero when the reset input is high
• 7442 – a BCD to decimal (1 of 10) decoder that can sink up to about 20mA with outputs that are active-low which means they become low when selected but are high at other times
• 7440 – a quadruple 2-input NAND gate employing TTL to achieve high speed at moderate power dissipation and provide the basic functions used in the implementation of digital integrated circuit systems due to its characteristics such as low output impedance, minimal variation in switching times with temperature, good capacitive drive capability, and high noise immunity

In the circuit, the movement of the ball is indicated in the successive lighting of the LED which comes one after the other. The moment that the last LED is reached, the movement of the lighting shifts to the opposite direction until it reaches the other end, and the process repeats automatically. Two inverters IC3A-B were used to provide the clocking in the circuit while the buffer is functioned by the third chip IC3C. The frequencies as well as the speed of the light movement are determined by C1, R1, and TR1. The speed is specifically regulated by TR1 but the change in the capacitor value will also greatly affect the speed proportionally.

From the IC1C-D is where the clock signals are passing, in which the detailed synchronous up/down counter of the IC2 is increased or decreased. The gates of ICA-B are responsible for the detailed increasing or clipping and they are connected to form the operation of a set/reset flip flop. This flip flop will cause the direction of LEDs D1 to D10 to shift movement upon reaching the limits of the bar. The process will continue until the circuit is continuously supplied.

The inputs of BCD decoder IC4 is driven 4 lines out of 10, by the four outputs of IC2 while the IC4 outputs are connected to LED D1-10. Every LED from 10 outputs remains in high state once it lights up while at some point, they will be at low state as the movement of light starts in reverse direction. Each LED is in correspondence with the output pins of IC4 whenever it changes its state. There is an alternative option to use in place of IC4 using 7442 that provides an output of 16mA, with a model 7445 that will provide an output of 80mA.

Figure 2 

The digital ping pong circuit is mainly used for the purpose of games, fun, and enjoyment for all ages that are into these recreational activities. They provide visual indications via the movement of light in the LED. In a more advanced application, this digital ping pong game are being applied in a variety of video game consoles like the modern Nintendo Wii that incorporates the use of electronic paddles.

Source:users.otenet.gr/~athsam/digital_ping_pong_1.htm