Die: A Tiny Little Gambling Device
We all know what a die (dice is plural) is and how it looks. Generally it is seen in the shape of a small cubical block having six plane surfaces with dots or numbers from 1 to 6 engraved on each of its surface respectively.
It is basically used to initiate a game by giving each individual involved a chance to throw the die. It’s also being very popularly used as a gambling device.
The die cube is shaken either inside a loosely held fist or inside a small container and thrown on the table. The dice rolls down and randomly settles to reveal one of its surfaces which carry the specific score (any digit in between 1and 6).
According to this figure or score the particular individual is allowed to proceed further in the game.
Inspired from this traditional playing device, many electronic versions of it has been already developed. Here we will discuss regarding a similar simple circuit of an electronic dice and see how we can actually go on to build it.
About the circuit
The circuit is basically made up of an oscillator whose output is fed to a counter and display stage.
The oscillator is switched ON manually by pressing a push button for a few seconds. The oscillator remains activated as long as the switch is depressed and provides a fast clock signal to the counter IC which converts these pulses into a digital display (1 to 6).
As long as the switch remains depressed the display cannot be read as the digits in it are changed very quickly, the moment the switch is released a randomly selected number in between 1 to 6 is displayed.
This selection of the displayed number is totally dependent on the time for which the switch remains depressed and even a difference of a microsecond is enough to alter the result, thus is completely unpredictable.
Let’s study precisely how the circuit actually functions through the following points:
The IC 4033, which is a 5-stage counter and a 7-segment decoder, driver forms the heart of the circuit. This IC is able to count and decode any frequency into a digital figure by directly driving a 7-segment LED display.
The oscillator stage is made up of two transistors and few other passive components and is basically an astable multivibrator. IC 4017 receives clock signals from the oscillator and resets the whole system after every 6 counts.
On pressing the switch S1, the astable is switch ON and starts providing rapid clock pulses to pin 14 of IC 4017. After every 6 clock pulses the IC is reset to make its pin 3 high which in turn resets IC 4033 so that the display can restart from digit 1.
The IC immediately starts counting these pulses and then make the counting visible on the 7-segment LED module. But as explained above since the clock pulses are produced rapidly, the display too changes in accordance with these pulses and cannot be read.
As soon as the switch is released, the astable stops producing the clock pulses, IC4033 stops counting and latches to any one randomly selected position and displays the relevant digit over the 7-segment LED display.
All Resistors 1/4 Watt 5%
R1…..R5 = 100 K,
R6, R9 = 470 Ohms,
R7, R8 = 150 K,
C1,C2 = 470nF, Ceramic,
T1, T2 = BC 547B,
IC1 = 4017,
IC2 = 4033,
SWITCH = PUSH-TO-ON,
LD1 = Common Cathode Display, 7-Segment,
PCB = General Purpose.
The circuit of this electronic dice can be easily assembled over a general PCB by soldering and interconnecting each of the components as per the given circuit schematic.
The assembled board along with a 9 volt battery may be housed inside a plastic enclosure having a small window cut out for the display to be visible. Also make sure to drill a correct sized hole for fixing the push button over the box. Similarly you may also fit the ON/OFF switch just beside the push button.
The unit is now complete and you may now share with your friends the fun of playing with this little all electronic die.