Electronic Dice Game

Abstract

A dice game simulated by means of two banks of seven electric lamps each will when activated, by means of a power switch, show present numbers. Four of the lamps are positioned in the corners of a square plus two in the middle of opposite sides and one in the center. The lamps are connected in logic circuitry which when operated ramdomly illuminates the lamps in such a manner as to simulate, with equal probability, the six sides of a die. The circuitry includes a free-running unijunction oscillator having an output coupled to a six-position ring counter.

Description

BACKGROUND OF THE INVENTION

The prior art shows many examples of simulated dice games. The U.S. Pat. to O'Neil No. 2,012,544 shows a dice game using electromechanical switching. Recently issued U.S. Pat. No. 3,459,427 issued to Rhodes discloses an electronics dice game, but its logic circuitry does not simulate real dice. The present invention is an improvement over the prior art in that it provides a system in which two dice are simultaneously operated at slightly different frequencies with realistic simulation of a real dice game and with simple, inexpensive, reliable, and accurate logic circuitry.

THE DRAWINGS

FIG. 1 is a schematic representation, partly in block form, of the overall dice game; and

FIG. 2 is an electronic schematic showing the circuitry for operating each die.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Referring to FIG. 1, the illustrated embodiment includes two identical banks of lamps 10 and 12 arranged to realistically simulate the six sides of a die. That is to say, each lamp represents a dot of a die, seven such lamps being provided and arranged so that upon selective illumination, any number from 1 to 6, corresponding to the six sides of the die, can be made to appear in the proper position. Thus, each bank of seven lamps is arranged in the general outline of the letter "H", i.e., 1, 5 and 4 are positioned in one vertical column, while the lamps 2, 6 and 3 are arranged in a parallel vertical column with the lamp 7 positioned in the middle, the lamps 1, 2, 3 and 4 being at the corners of a square. With this arrangement, the various combination of dots from 1 to 6 on the six sides of a die may be represented by illumination, respectively, of one, the center lamp (7), two, the diagonal lamps (2,4), three, the opposite diagonal lamps and the center lamp (1,3,7), four, the four corner lamps (1,2,3,4), five, the four corner lamps and the center lamp (1,2,3,4,7), and six, the two vertical rows of lamps (1,2,3,4,5,6).

In order to simulate a dice game, the illumination of the various combinations of lamps must be random for both dice and there must be equal probability of any number occurring. This requirement will be met if the oscillator frequency is stable and independent of its loads. For this purpose each of the banks of lamps 10 and 12 incorporates logic circuitry which is randomly selected by means of free-running unijunction oscillators 14 and 16. Both oscillators are identical except that their resistance capacitance values are different so that they operate at slightly different pulse repetition rates. In this way the selection of combinations of lamps in bank 10 is random, and in addition is different from the random selection of lamps in bank 12.

Each oscillator includes a unijunction transistor 18 having its base 1 electrode 20 connected to ground through a resistor 22, its base 2 electrode 24 connected to a battery 26 through an operating switch 28 and a power switch 30. A resistor 32 and a capacitor 34 are connected in series between the base 2 electrode 24 and ground. The emitter electrode 36 of the unijunction transistor 18 is connected to the junction of resistor 32 and capacitor 34.

When the power switch 30 is closed, voltage from the battery 26 is applied across respective R.C. networks, each including a capacitor 38 and a resistor 40, to a respective bank of lamps 10 and 12 to provide an initial setting on each die. Subsequent closing of operating switch 28 initiates the operation of the oscillators 14 and 16, which operation will continue for as long as the operating switch 28 is in a closed position.

While the operating switch 28 is closed, the timing capacitor 34 is charged through the timing resistor 32 until the voltage at the emitter electrode 36 reaches the unijunction peak point voltage, at which time the unijunction transistor 18 conducts. This causes timing capacitor 34 to discharge through resistor 22, thereby decreasing the emitter voltage until the emitter electrode ceases to conduct, at which point the unijunction transistor 18 turns off. Thereafter the timing capacitor 34 recharges through the resistor 32 and the oscillation continues until the switch 28 is opened.

The output from the unijunction transistor appears across the resistor 22 as a pulse train having a repetition frequency determined by the values of the resistors 32 and capacitors 34 and the oscillator 14 differ from those of the same elements in the oscillator 16. In this way the timing cycles of the oscillators are different. The randomness results from the fact that the timing cycle is too fast for human reaction, and therefore any slight variation in the length of time the operating switch 28 is maintained depressed results in a random selection of a particular group of lamps in each bank.

The circuit for the light banks 10 and 12 is shown in FIG. 2 and it includes a six-stage cathode-coupled ring counter consisting of 6 silicon controlled rectifiers Q1-Q6, each having an anode electrode, a cathode electrode and a gate electrode. Each silicon-controlled rectifier has an individual gate drive circuit for driving the gate electrode with a shift pulse from the oscillators. Each gate drive circuit includes an associated diode CR1-CR6 and a respective capacitor C1-C6 and a respective resistor R1-R6. The shift pulses from the oscillators are applied via shift line 54. In addition, each silicon controlled rectifier has an individual "turn off" capacitor C1a-C6a, respectively, each of said capacitors C1a-C6a being connected to a gate drive circuit through a respective resistor R1a-R6a.

The lamps 1-7 are connected across the battery 26 in various combinations sequentially through one of the silicon controlled rectifiers Q1-Q6 by means of a diode matrix generally indicated at 56, and including diodes D1-D12. The particular light combination is determined by that silicon controlled rectifier Q1-Q6 which is in a state of conduction. Thus, when the rectifier Q1 conducts, the lamp 7 is illuminated by a connection through the diode D1. When the rectifier Q2 is conducting, the lamps 2 and 4 are simultaneously illuminated by means of a connection through the diode D2. When the rectifier Q3 is conducting, the lamps 1 and 3 are illuminated by means of a connection through the diode D4 while the lamp 7 is illuminated by means of a connection through the diode D3. When the rectifier Q4 is conducting, the lamps 2 and 4 are illuminated by means of a connection through the diode D5, while the lamps 1 and 3 are illuminated by means of a connection through the diode D6. When the rectifier Q5 is conducting, the lamp 7 is illuminated by means of a connection through the diode D7, the lamps 2 and 4 are illuminated by means of a connection through the diode D8 and the lamps 1 and 3 are illuminated by means of a connection through the diode D9. When the rectifier Q6 is conducting, the lamps 2 and 4 are illuminated by means of a connection through the diode D10, the lamps 1 and 3 are illuminated by means of a connection through diode D11, and the lamps 5 and 6 are illuminated by means of a connection through diode D12.

The operation of the ring counter is as follows:

Closure of the power switch 30 applies battery power to the capacitor 38 and resistor 40 and to one side of the indicating lamps 1-7. The differentiation action of the capacitor 38 and resistor 40 generates a pulse at the junction 46. The pulse at junction 46 may be used to preset any of the silicon controlled rectifiers Q1-Q6 to its "on" state and initially illuminate any selected number from one to six, corresponding to the six sides of a die, to provide any desired combination of the dice. The pulse at junction 46 is coupled, by way of an example, via capacitor C1 to the gate electrode of the silicon controlled rectifier Q1. This pulse presets the silicon controlled rectifier Q1 to its "on" state, however, the rectifiers Q2-Q6 remain in their "off" state and capacitors C2-C6 will charge to the battery voltage through resistors R2-R6, respectively. The commutating capacitors C1a and C3a through C6a will charge through the lamps 1-7, the various diodes in the diode matrix and through the conducting silicon controlled rectifier Q1. Since silicon controlled rectifier Q1 is in its conducting state, its anode is approximately at ground potential, and therefore neither the capacitor C2 nor the capacitor C2a will charge. When the push-button operating switch 28 is depressed, the oscillators 14 and 16 begin to oscillate and generate a shift pulse across the respective resistors 22. When this shift pulse arrives at the shift line 54, only the silicon controlled rectifier Q2 can be triggered to the "on" condition since its gate steering diode D2 is the only gate steering diode not back-biased by a precharged capacitor. However, as the silicon controlled rectifier turns on, the capacitor C3a discharges and momentarily drives the common cathode line to the supply voltage. When the common cathode line momentarily goes positive, the silicon controlled rectifier Q1 is back-biased and forced to "turn off".

When the next shift pulse arrives at the shift line 54, silicon controlled rectifier Q3 turns on and the silicon controlled rectifier Q2 turns off. This stepping action repeats until Q4, Q5 and Q6 sequentially turn on. Thereafter, the cycle repeats at Q1.

OPERATING PARAMETERS OF A WORKING EMBODIMENT

The following is an example of the parameters used in a working embodiment of this invention. While not limiting the scope of the invention, the parameters may be useful in enabling persons skilled in the art to make a model of the invention.

Transistor 18 Type 2N4781 Silicon Controlled Rectifiers Q1-Q6 Type TIC44 Capacitors C1-C6 .005 uf C1a-C6a 2.2 uf 34 1.0 uf 38 .05 uf Resistors 22 270 ohms 32 (Oscillator 14) 10 K 32 (Oscillator 16) 8.0 K 40 100 K R1-R6 1 K R1a-R6a 10 K

with the particular parameters chosen for the oscillators 14 and 16, the shift frequency output of oscillators 14 is 100 hz. The shift frequency output of the oscillators 16 is 125 hz.

Claims

I claim:

1. In an electronic dice game having first and second banks of seven lamps, said lamps being positioned to simulate, when selectively illuminated, the six sides of a die, the combination comprising:

a source of direct current;

first and second ring counters, each having six interconnected stages, means for initially presetting any one of said stages in each of said ring counters to a conducting state while maintaining the remainder of said stages in a nonconducting state, each of said stages comprising a silicon controlled rectifier, one of said silicon controlled rectifiers being initially preset in a conducting state while the remainder of said silicon controlled rectifiers are maintained in a nonconducting state;

means for sequentially shifting the conduction states of the silicon controlled rectifiers in said stages in each of said counters whereby only one of the silicon controlled rectifiers in each counter conducts while the remaining of said silicon controlled rectifiers are maintained in a nonconducting state, said means for sequentially shifting said conduction states comprising the pulse output of first and second free-running oscillators, said outputs being connected to said first and second ring counters, respectively, said free-running oscillators having different time constants so as to produce output pulses having different repetition frequencies;

first and second diode matrices for selectively connecting predetermined combinations of said first and second banks of lamps, respectively, to said source through said sequentially conducting silicon controlled rectifiers in said first and second counters, respectively, each of said silicon controlled rectifiers having a cathode connected to one side of said source, an anode connected to the other side of said source through one of said diode matrices and through selected combinations of lamps in a respective bank, said combinations being selected by said diode matrix, and a gate electrode, said means for sequentially shifting the conduction states of said silicon controlled rectifiers including a connection of said pulse output from a respective oscillator to each of said gate electrodes, each of said connections including a first capacitor, and the anodes of adjacent silicon controlled rectifiers in said ring counter being connected by second capacitors;

and manually operable switch means, said switch means connecting said source to said oscillators for simultaneously controlling the energization of said oscillators, the length of time of energization of said oscillators being random whereby at the end of such time the probabilities of any one of said stages remaining conductive is equal to the probability of any other of said stages remaining conductive.

2. The invention as defined in claim 1 wherein said means for initially presetting any one of said silicon controlled rectifiers includes a connection from said source to said one silicon controlled rectifier in each of said ring counters, said connection including a differentiating network connected across said source, the output of said differentiator being coupled to the gate electrode of said silicon controlled rectifiers through its associated first capacitor.

3. The invention as defined in claim 2 wherein said diode matrix includes a first diode interconnecting a first lamp and a first silicon controlled rectifier, a second diode interconnecting parallel connected second and third lamps and a second silicon controlled rectifier; third and fourth diodes, said third diode interconnecting said first lamp and a third silicon controlled rectifier, said fourth diode interconnecting parallel connecting fourth and fifth lamps and said third silicon controlled rectifier; a fifth and sixth diode, said fifth diode interconnecting said parallel connected second and third lamps and a fourth silicon controlled rectifier, said sixth diode interconnecting said fourth and fifth parallel connected lamps and said fourth silicon controlled rectifier; seventh, eighth and ninth diodes, said seventh diode interconnecting said first lamp and a fifth silicon controlled rectifier, said eighth diode interconnecting said second and third parallel connected lamps and said fifth silicon controlled rectifier, said ninth diode interconnecting said fourth and fifth parallel connected lamps and said fifth silicon controlled rectifier; and tenth, eleventh and twelfth diodes, said tenth diode interconnecting said second and third parallel connected lamps and a sixth silicon controlled rectifier, said eleventh diode interconnecting said fourth and fifth parallel connected lamps and said sixth silicon controlled rectifier, and said twelth diode interconnecting sixth and seventh parallel connected lamps and said sixth silicon controlled rectifier.

4. In an electronic dice game having first and second banks of seven lamps, said lamps being positioned to simulate, when selectively illuminated, the six sides of a die, the combination comprising:

a source of direct current;

first and second ring counters, each having six interconnected stages, means for initially presetting any one of said stages in each of said ring counters to a conducting state while maintaining the remainder of said stages in a nonconducting state, each of said stages comprising a silicon controlled rectifier, one of said silicon controlled rectifiers being initially preset in a conducting state while the remainder of said silicon controlled rectifiers are maintained in a nonconducting state;

means for sequentially shifting the conduction states of the silicon controlled rectifiers in said stages in each of said counters whereby only one of the silicon controlled rectifiers in each counter conducts while the remaining of said silicon controlled rectifiers are maintained in a nonconducting state, said means for sequentially shifting said conduction states comprising the pulse output of first and second free-running oscillators, said outputs being connected to said first and second ring counters, respectively, said free-running oscillators having different time constants so as to produce output pulses having different repetition frequencies;

first and second diode matrices for selectively connecting predetermined combinations of said first and second banks of lamps, respectively, to said source through said sequentially conducting silicon controlled rectifiers in said first and second counters, respectively, each of said silicon controlled rectifiers having a cathode connected to one side of said source, an anode connected to the other side of said source through one of said diode matrices and through selected combinations of lamps in a respective bank, said combinations being selected by said diode matrix, and a gate electrode, said means for sequentially shifting the conduction states of said silicon controlled rectifiers including a connection of said pulse output from a respective oscillator to each of said gate electrodes;

and manually operable switch means, said switch means connecting said source to said oscillators for simultaneously controlling the energization of said oscillators, the length of time of energization of said oscillators being random whereby at the end of such time the probabilities of any one of said stages remaining conductive is equal to the probability of any other of said stages remaining conductive.