With the help of this circuit one can create an entertaining electronic game that resembles a little roulette wheel of fate!
When the game begins a circle of ten lights flashes in a random order.
Until only one light remains ON the lights continue to change.
The winner is that!
Since one never know which light will remain ON playing is always a surprise.
Circuit Working:
Parts List:
| Component | Quantity |
|---|---|
| Resistors | |
| 120Ω 1/4 watt | 1 |
| 330Ω 1/4 watt | 1 |
| 1k 1/4 watt | 1 |
| Capacitors | |
| Electrolytic 4.7μF 25V | 1 |
| Semiconductors | |
| IC 7413 | 1 |
| IC 7493 | 1 |
| IC 7445 | 1 |
| LEDs 5mm 20mA | 10 |
| Push to off switch | 1 |
It is easy to construct a ten sided die wheel of fortune for many different kinds of uses.
When switch S1 is pressed pin 1 of IC 7413 becomes high which causes the game to begin spinning.
This sets off wave pulses that switch pin 14 by activating an oscillator at IC 7413.
Pin 14 is a component of IC2 a four bit counter.
When S1 is released the oscillation stops.
By stopping the wheel at a set point IC2 further uses a high frequency oscillator to count the amount of pulses generated while S1 is opened to try to avoid cheating.
The decimal converter IC3 and BCD both receive the four bit data.
An lighted LED indicates that one of IC3s ten outputs is low as long as the counter DCBA is less than 1001.
For example output 6 of IC3 will be low lighting up D7 if DCBA = 0110.
Of the 16 possible steps only 10 are processed by the IC 7445.
The players turn ends when the DCBA hits values between 1010 and 1111 at which point all outputs are high and no LED is lighted.
A one of sixteen decoder such as the 24 pin type 74154 along with a number of resistors and six LEDs can be used to increase the number of possible outcomes in the game to sixteen.
A 16 sided die wheel of fortune can be generated using this modified circuit.
Formula:
The IC 7413 formula is a dual 4 input positive NAND gate as it includes two independent NAND gates each with four inputs.
NAND gates function logically and provide the following logic when they are used with binary inputs (0 or 1):
Output = NOT (A AND B AND C AND D)
where,
- A, B, C and D are the four input bits.
- NOT stands for logical negation where 0 becomes 1 and vice versa.
- AND stands for a logical conjunction where each input must be 1 for the output to be 1.
Additional details on IC 7413:
Table of Truth:
This table shows the output logic for every possible combination of input bits (0000, 0001 etc.) for each of the integrated circuits two NAND gates.
The truth table can be found in the manufacturers datasheet or other sites.
Configuration of Pins:
Each of the 14 pins on the integrated circuit has a specific function for the inputs (numbers 1 through 8) outputs (numbers 3, 6, 11 and 14) for each of the two NAND gates and the power supply (VCC and GND).
The datasheet will provide a pin diagram for proper connection.
Specifications for operation:
The datasheet provides information on the working voltage range, current consumption and propagation delay the time it takes for the output to respond to an input change.
Note:
The IC 7413 is controlled by the logic of NAND gates.
Knowing how to connect the inputs and outputs based on the pin configuration is necessary while using the truth table in digital circuits.
How to Build:
To build a Simple Roulette Wheel of Fortune Circuit below steps are important to follow:
Putting the Parts Together:
- Put the ICs on the PCB.
- Connect the PCBs positive terminal to the power source.
Connect the oscillator:
- To produce pulses connect the components of the oscillator circuit to IC 7413.
- Connect pin 14 of IC2 to the oscillators output.
Include the Switch:
- Connect the switch S1 to the electrical circuit.
- Pin 1 of IC 7413 should go high when it is pushed starting the oscillation.
Reverse Logic:
- As the game progresses IC2 counts pulses in a counter like manner.
- The output should be connected to IC3s BCD input.
Decimal to BCD Conversion:
- The binary coded decimal BCD output from IC2 is converted into a decimal number by IC3.
- Connect the LEDs to the IC3s outputs each of which should reflect a distinct decimal number.
LED lighting and decoding:
- To decode the decimal output use IC 7445.
- Connect the LEDs to its outputs.
- Make sure the decoded values cause the LEDs to illuminate.
Stop Cheating:
- Make sure the oscillator frequency is set high enough that users can not foresee or control the outcome by stopping the wheel at a particular location.
Logic at the End of Turn:
- Use logic to figure out when a players turn is over when particular needs are met.
- Press the switch to test the circuit watch the LED sequence and confirm that the result is random.
Complete and Safeguard:
- After confirming that the circuit functions as planned think about completing the connections and fastening them to avoid accidental disconnections.
Conclusion:
Electronic games, educational equipment and entertainment systems that require an element of chance often use this type of circuit.
It provides an electrical controlled version of a spinning wheel which is frequently used in games of chance such as wheel of fortune or roulette.
When dealing with electronic circuits do not forget to review datasheets for the individual components and take safety precautions into mind.
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