This circuit shows you how to build a fun electronic game like a mini roulette wheel of fortune!
It has a circle of 10 lights that light up in a random order when you start the game.
The lights keep changing until only one light is left on.
That is the winner!
It is like a surprise every time you play because you never know which light will stay on.
Circuit Working:
Parts List:
Component | Description | 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 |
7493 | 1 | |
7445 | 1 | |
LEDs | 5mm 20mA | 10 |
Switches | ||
Push to off switch | 1 |
Constructing a 10 sided die wheel of fortune for various applications is simple.
The game starts spinning when switch S1 is pressed, causing pin 1 of IC 7413 to go high.
This triggers an oscillator at IC 7413 initiating wave pulses that switch pin 14.
Pin 14 is part of a four bit counter IC2.
Releasing S1 brings the oscillation to a halt.
IC2 also tallies the number of pulses while S1 was open using a high frequency oscillator to prevent cheating by stopping the wheel at a specific point.
The four bit information is fed into BCD and IC3 a decimal converter.
As long as the counter DCBA is less than 1001 one of the 10 outputs of IC3 remains low indicated by an illuminated LED.
For example, if DCBA = 0110, output 6 of IC3 will be low lighting up D7.
IC 7445 decodes only 10 out of the total 16 possible stages.
When DCBA reaches values from 1010 to 1111 all outputs are high, and no LED is lit, signaling the end of the players turn.
To expand the game to 16 outcomes IC3 can be replaced with a one of sixteen decoder, like the 24 pin type 74154 along with a series of resistors and half a dozen LEDs.
This modified circuit will function as a 16 sided die wheel of fortune.
Formula:
Formula for IC 7413 has two separate NAND gates, each having four inputs, making it a dual 4-input positive-NAND gate.
When NAND gates are used with binary inputs (0 or 1), they operate logically, and the following logic is output:
Output = NOT (A AND B AND C AND D)
where,
- These are the four input bits: A, B, C, and D.
- Logical negation is represented by “NOT” (0 becomes 1 and vice versa).
- A logical conjunction is denoted by “AND“, the output is 1 only when all of the inputs are 1.
More information about IC 7413:
Truth Table: For each of the two NAND gates in the integrated circuit, this table displays the output logic for all conceivable combinations of input bits (0000, 0001, etc.).
The truth table is available in internet resources or the manufacturers datasheet.
Pin Configuration: The integrated circuit consists of 14 pins, each of which serves a distinct purpose for the power supply (VCC and GND), inputs (numbered 1 through 8), and outputs (numbered 3, 6, 11, and 14) for each of the two NAND gates.
For correct connection, a pin diagram will be included in the datasheet.
Operating Specifications: The operating voltage range, current consumption, and propagation delay (the amount of time it takes for the output to react to a change in the input) are all listed in the datasheet.
Note:
The logic of NAND gates controls the behavior of the IC 7413.
Using the truth table in digital circuits requires an understanding of how to link the inputs and outputs according to the pin arrangement.
How to Build:
Building a Wheel of Fortune game circuit involves a combination of electronic components and some basic understanding of electronics.
Assemble the Components:
- Place the ICs on the PCB.
- Connect the power supply to the positive terminal of PCB.
Connect the Oscillator:
- Connect the oscillator circuit components to IC 7413 to generate pulses.
- Connect the output of the oscillator to pin 14 of IC2.
Integrate the Switch:
- Connect the switch S1 to the circuit.
- When pressed, it should make pin 1 of IC 7413 go high initiating the oscillation.
Counter Logic:
- IC2 acts as a counter, counting pulses during the game.
- Connect its output to the BCD input of IC3.
BCD to Decimal Conversion:
- IC3 converts the binary coded decimal BCD output from IC2 into a decimal number.
- Connect the outputs of IC3 to the LEDs with each LED representing a different decimal value.
Decoding and LED Illumination:
- Use IC 7445 to decode the decimal output.
- Connect its outputs to the LEDs.
- Ensure that the LEDs light up based on the decoded values.
Prevent Cheating:
- Adjust the oscillator frequency to a high enough value to prevent users from predicting or controlling the outcome by stopping the wheel at a specific spot.
End of Turn Logic:
- Implement logic to detect the end of the players turn when certain conditions are met.
- Test the circuit by pressing the switch, observing the LED sequence and verifying that the outcome is indeed random.
Finalize and Secure:
- Once you have verified that the circuit works as intended consider finalizing the connections and securing them to prevent accidental disconnections.
Conclusion:
This kind of circuit is often used in electronic games educational devices or entertainment systems where a random element is desired.
It offers a controlled and electronic representation of a spinning wheel commonly seen in games of chance like roulette or wheel of fortune.
Remember to consult datasheets for the specific components and consider safety precautions when working with electronic circuits.
Leave a Reply