GB2267050A

GB2267050A - Electric maze learning device or game apparatus and printed circuit switch and method of fabricating same

Info

Publication number: GB2267050A
Application number: GB9308666A
Authority: GB
Inventors: Boyd Gordon Watkins; Dennis George Lomax
Original assignee: Interel Inc
Current assignee: Interel Inc
Priority date: 1992-05-19
Filing date: 1993-04-27
Publication date: 1993-11-24
Also published as: CA2094312A1; GB9308666D0

Abstract

A printed circuit board switch and a method for producing it are shown. The switch includes a conductive plug of a first diameter, and a printed circuit board. The printed circuit board defines a first hole A of substantially the first diameter, a pair of half circles B of a substantially smaller second diameter on opposite sides of the first hole extending outward and away from the centre of the first hole, and first and second conductive switch poles 4, 5 on at least one side of the board on opposite sides of the first hole and extending into and along opposite sides of the sides of the first hole. With this switch configuration, closure of the first and second conductive switch poles is effected when the conductive plug is inserted into the first hole. The switch may be produced by drilling holes A + B in the printed circuit board depositing conductive material on the sides of the holes and selectively removing the material therefrom to isolate the holes into 2 parts. A banana jack 6 may then be inserted in the hole to complete the circuit. The printed circuit board may be used as pan of an electric maze learning device or game. <IMAGE>

Description

ELECTRIC MAZE LEARNING DEVICE OR GAME APPARATUS AND PRINTED CIRCUIT SWITCH AND METHOD OF FABRICATING SME The present invention relates to a number or earlier developed devices to enhance the development of problem-learning skills for groups whether they wish to do team building, management development, or to develop other group skills. Only one device is known to the inventors that is similar to the present invention and that device is "Electric Maze" from Interel, Inc., wherein Interel, Inc. is also the assignee of the present invention.

The "Electric Maze" consists of a carpet laid out in a grid form having 20 pressure switches in a rectangular array, and a console having 20 toggle switches, an alarm and a battery power source. In the carpet, one side of each of the 20 switches is connected to a common point and a single pin in an associated connector. The other side of each of the 20 switches is connected individually to 20 individual pins in the same connector that is associated with the carpet.

There is a similar connector on the console with one pin associated with the common connection, point of the switches in the carpet connected to the return terminal of the battery. Additionally, one side of each of the 20 toggles switches in the console is connected individually to 20 individual pins in the console connector with each of those pins corresponding to one of the 20 switch pins in the carpet connector. The other side of each of the 20 toggle switches in the console is connected to a common point which in turn is connected to the negative terminal of the alarm, with the positive terminal of the alarm connected to the positive terminal of the battery.

Additionally, there is a 21 wire cable to interconnect the carpet to the console. Thus, when the carpet and console are connected together there is a series connection of each one of the pressure switches in the carpet with a different one of the toggle switches in the console. Each of these series switch paths are connected in parallel between the battery return and the alarm negative terminal. Thus, it can be seen in this design that if the size of the carpet and console arrays were to grow, there would be an additional wire in the interconnecting cable for each added series pair of switches in the carpet and console.

That presents a very practical limitation since the size of the necessary cable and console will grow very rapidly, making the resulting unit larger and larger, and heavier and heavier, which very quickly will reduce the portability of the final unit. For those reasons it is desirable to keep the size of the necessary cable down to 22 wires so that â standard 22 pin connector can be used.

Additionally, since the space necessary to mount even the smallest toggle switches requires at least 1 square inch of space, the size of the console will similarly grow quite rapidly.

Thus, it would be desirable to have a system wherein the 22 pin limit can be maintained and the size of the console kept under control while at the same time allowing for more switches within the grid, if desired.

The present invention provides a design that can have up to a 121 switch grid with only a 22 pin connector and a console grid size that is approximately h the size that the console of the prior art would be.

One embodiment of the present invention, in accordance with the disclosed embodiments, shows a learning, or game, device for use by two or more persons.

That device has a first switch array with a plurality of switches in a particular geometric configuration, and each switch has an open and a closed position to be selectively controlled by a first person. Additionally there is a second switch array that has the same number of switches as the first switch array and the same geometric configuration with each switch in the second switch array being in a corresponding location to a switch in the first switch array. Each switch in the second array also has an open and a closed position and is disposed for selective closure by at least one person other than the first person that has control of the first switch array.Further there is a mode selection device for manually selecting between a first and a second operating mode, and a scanning device for simultaneously scanning the switches in the first and second switch arrays in corresponding locations within each array. Still further there is a detection circuit to produce a signal when the first mode is selected and corresponding switches in both the first and second switch arrays are in the closed position, or when the second mode is selected and one or more switches in the first switch array is closed and the corresponding one or more switches in the second switch array is open. The detection circuit is followed by an alarm that is responsive to the detection circuit to signal the users of the present invention whenever the condition associated with the selected mode is met.

In an alternative embodiment of the present invention, the first and second switch arrays each are in a rectangular configuration that is organized into X rows and Y columns with each array having X times Y switches with each switch in each array connected between a different combination of rows and columns.

In accordance with another one of the preferred embodiments of the present invention there is shown a method for producing a printed circuit switch for closure with a separate conductive plug having a conductive shaft that includes spring fingers that can be compressed with the spring fingers having a first diameter when the fingers are fully expanded and a second smaller diameter when the fingers are compressed to be inserted thereinto for such purpose.The method includes the steps of selecting a printed circuit board having conductive foil adhering to at least one side thereof, drilling a first hole of a third diameter through the printed circuit board wherein the third diameter is intermediate the first and second diameters, and drilling a pair of second holes of a substantially smaller fourth diameter than the third diameter on opposite sides of the first hole at substantially opposite ends of a diameter line of the first hole and with the center of each of the pair of second holes located substantially on the edge of the first hole. Then a conductive material is deposited at least on the exposed sides of the first and second holes through the printed circuit board, followed by the removal of the conductive material deposited on at least a portion of the second holes after completion leaving at least a portion of the conductive material deposited on the sides of the first hole to make electrical contact with the conductive plug when it is inserted into the first hole.

When the conductive plug is so inserted it makes electrical contact to each side of the first hole in the finished printed circuit switch. Then the conductive foil on the surface of the printed circuit board is selectively etched to form the poles of the switch.

In accordance with another embodiment of the present invention there is shown a printed circuit switch that includes a conductive plug having a conductive shaft that includes spring fingers that can be compressed with the spring fingers having a first diameter when the fingers are fully expanded and a second smaller diameter when the fingers are compressed, and a printed circuit board.The printed circuit board defines a first hole of a third diameter wherein the third diameter is intermediate the first and second diameters, a pair of half circles of a substantially smaller fourth diameter than the third diameter on opposite sides of the first hole at substantially opposite ends of a first diameter line of the first hole and extending outward and away from the center of the first hole, and first and second conductive switch poles on at least one side thereof with each of the first and second poles located on opposites sides of a second diameter line of the first hole substantially perpendicular to the first diameter line and extending into and along opposite sides of the sides of the first hole.With this switch configuration, closure of the first and second conductive switch poles is effected when the conductive plug is inserted into the For a better understanding of the invention and to show how the same may be carried into effect reference will now be made by way of example to the accompanymg drawings, in which: Figure 1 is a simplified schematic diagram of the game and learning device of the present invention.

Figure 2 is a schematic diagram of a matrix of switches for use with some implementations of the game and learning device of the present invention.

Figure 3 is a detailed block schematic diagram of the game and learning device of the present invention.

Figure 4 illustrates the hole pattern to be drilled in a printed circuit board to create the switch of the present invention.

Figure 5 is a plan view of one side of a section of a printed circuit board illustrating the printed circuit portions of the switch of the present invention.

Figure 6 is a side view of a banana jack for use with the present invention.

Figure 7 illustrates the printed circuit layout of a matrix of switches of the present invention for use with the game and learning device.

The learning device, or game, of the present invention is built around two matrices of switches. Each of the two matrices is of the same configuration, each having X rows and Y columns, with an individual switch interconnecting each row with each column for a total of X times Y switches. In the learning device, one of the matrices of switches may be laid-out in the form of a carpet of X by Y identically shaped regions, each region having a pressure sensitive switch therein so that when that region of the carpet is stepped upon there is a closure of the corresponding switch. The second matrix of switches is located in a control module and is programmable for selective closure of the switches in that matrix of switches.The control module also includes circuitry for scanning the switches in each matrix to determine whether they are open or closed and to signal the users of the device when, in a first mode that the corresponding switches in both matrices are both closed, or in a second mode that when one or more switches in the control module are closed and the corresponding switches in the matrix in the carpet are open.

In the game situation, both matrices of switches are individually programmable by the players. Here, the control module is contained in one of the playing units that also contains one of the matrices of switches.

Similar to the learning system, the game also has two modes of operation. In one mode a signal is sounded when the corresponding switches in both matrices is closed, and in the other mode a signal is sounded when one or more switches in the control module are closed and the corresponding switches in the matrix of the other playing unit are open.

Figure 1 schematically illustrates the operation of a simplified first embodiment of the game and learning device of the present invention where there is only one switch in each of the matrices. The logic used in this circuit is inverse, or negative logic, in that a high voltage level (say +v) represents a logical "o" and a low voltage level (say Ov) represents a logical "1". Those switches are illustrated by switches 10 and 12 each having a reverse diode D1 and Dz, respectfully, connected to a common input terminal that is disposed to receive an inverted pulse signal as shown to the left of the schematic.With the inclusion of diodes D1 and D2, the input terminal of switches 10 and 12 are either left floating when the inverted pulse signal is not present or connected to Ov through those diodes when the inverted pulse signal is present. The other terminal of switch 10 is connected to the input line of an open-collector inverter 14 and to the positive voltage bus, Vcc, via a pull-up resistor 28.

The other terminal of switch 12 is connected to Vc via pull-up resistor 30, and the input line of opencollector inverter 16 and inverter 22. The output line of inverter 22 is connected to the input line of opencollector inverter 23, and the output lines of inverters 16 and 23 are connected to the input line of opencollector inverter 24. Additionally, there is a switch 18 for the user to select the mode of operation of the learning device of the present invention. In position A the first mode discussed above is selected and inverter 16 is powered via switch 18. In position B the second mode discussed above is selected and inverters 22 and 23 are powered via switch 18 instead of inverter 16.

Inverter 24 is also connected to the power line, Vcc, via gating transistor T1. Transistor T1 is controlled by the input clock signal (substantially the same as an inverted pulse signal as discussed above) shown to the left in Figure 1, slightly delayed by Ri and C1 to allow the output signals of the earlier inverters in the circuit time to stabilize before inverter 24 reacts. This is done to prevent false alarms.

In operation then, there is no alarm sounded when the inverted pulse signal is applied and both switches 10 and 12 are open, regardless of the position of switch 18. When switch 18 is in position A the system is in the first mode (alarm only sounds when both switches 10 and 12 are closed), and when it is in position B it is in the second mode (alarm sounds only when switch 10 is closed and switch 12 is open). Those conditions are the only conditions in each of the two modes of operation where the output line of inverters 14 and 16 or 23 are both at a positive voltage and able to cause inverter 24 to toggle states. Without both output lines being high, since open-collector inverters were used in this embodiment of the present invention, the voltage level on the input line of inverter 24 is not sufficiently high to cause inverter 24 to change state. Thus when inverter 24 changes state, the voltage on the output line drops for substantially the duration of the clock pulse allowing current to flow through the alarm 26 causing it to sound for that period of time.

In a useful application there will have to be more than a single switch in each of the legs of the circuit. Those switches can take any form and be arranged in any desired configuration, e.g. a rectangular matrix, concentric circles, or any other geometric shape. One configuration that is useful for the game and the learning device of the present invention is a rectangular configuration with the switches arranged in a pattern with uniform spacing between them. In that configuration the switches could be in a parallel configuration with as many input lines as output lines, or they could be in a matrix configuration wherein the product of the number of input lines by the number of output lines is equal to the number of switches.

Figure 2 illustrates an 8x6 matrix of 48 switches having 8 input, or column, lines labelled A-H and 6 output, or row, lines labelled 1-6. Each switch in the matrix consists of a series combination of a switch and a diode with the cathode end of the diode connected to the corresponding column line. By using the matrix approach, the number of interface lines is simply the total of the number of rows plus the number of columns, whereas if each switch was individually connected to the control unit the number of lines would be twice the number of switches in the array. For example, in layout of 8 switches across by 6 switches wide there are 48 switches. If they are individually connected to the control unit there will be 96 lines, however, if they are interconnected as an 8x6 matrix there will be 6 + 8 = 14 lines.

The switches in any arrangement can be implemented in a number of ways ranging from an ordinary toggle switch to a post type switch where a plug is inserted into a hole to provide closure of the switch. A new type of the second type of switch just mentioned is discussed below in relation to Figures 4-7.

Figure 3 is a detailed block diagram of the circuit of the learning device of the present invention with the individual switches in Figure 1 having been replaced by 8x6 switch matrix arrays like those of Figure 2. To simplify this figure so as not to have to show all of the parallel lines, the lines that actually represent multiple lines have been marked to indicate how many lines they actually represent. Additionally, instead of showing all of the pull-up resistors and inverters, each of these have been shown in blocks which represent 6 of each of those devices. Since the chips that are used to implement the circuit normally contain 6 inverters each, it is also convenient to show them in that grouping. This also allows the showing of a single power connection to inverter blocks 120-124.Additionally, those inverters that were open collector or closed collector in Figure 1 have been expanded to a corresponding group of inverters that are each either open or closed collector within that group.

In this figure there is shown an oscillator 100 with the output line connected to the clock line of an eight bit ring counter 102 and to the R1 - C1 time delay connected to the base of transistor T1. The output line from each stage of ring counter 102 are each connected to corresponding individual column lines in switch matrix arrays 106 and 108, as well as, individually to the eight input lines of NAND gate 104. The output line of NAND gate 104 in turn is connected to the toggle input line of ring counter 102. Oscillator 100 defines the length of the output pulse from ring counter 102, on each one of it's eight output lines.When each of those pulses occur it is applied to the corresponding one of the input lines of NAND gate 104 causing an output signal from NAND gate 104 that triggers a shift of the stored bit in ring counter 102 so that when the next clock pulse from oscillator 100 occurs the output pulse from ring counter 102 occurs from the next output stage of ring counter 102.

Thus, when switch 54 of Figure 2 is closed, a downward step pulse will appear on row line 4 when the pulse from ring counter 102 is applied to column line D. Then the stage of inverter 118 that corresponds to row line 2 will change state. Depending on the position of mode selection switch 116 and the state of switch S4D in switch array 108 will determine whether alarm 126 sounds in the same way as discussed in relation to the operation of the simplified circuit if Figure 1. In essence ring counter 102 and NAND gate 104 provide a sampling system for monitoring each one of the corresponding 8 columns in switch arrays 106 and 108 one at a time. In all other ways this circuit operates the same as the circuit in Figure 1.

In the game version of the present invention there are two consoles each containing one of the switch arrays 106 and 108 for use by one of two players. The remainder of the circuitry can be divided between the two consoles as is convenient, however, in each possible division of the monitoring circuit there will be a number of lines between the two consoles that is equal to the sum of the number of columns and rows in either one of the switch arrays. In the specific example illustrated here there will be 14 lines (8+6). The games that can be played vary depending on the position of mode switch 116 and whether the individual switches are toggle switches or pole insertion switches.One game that can be played with the mode switch in position A and when pole type switches are used is shark checkers This differs from ordinary checkers in that neither player allows the other player to see their console, and, as in checkers, each player has a limited number of switch pole pieces. As the two players take turns inserting the plug pieces of their switches into the console to close various switches, if the alarm sounds in doing so that player looses that plug piece.

Then when time is called, or when one player has lost all of the pole pieces, the player with the most, or remaining pole pieces, is the winner.

In the learning device version of the present invention the monitoring circuitry and the second switch matrix 108 are included in a control console. The first switch matrix 106 typically will be in the form of a carpet with individual panels laid-out in the same fashion as the second switch matrix 108 with at least a pressure sensitive switch in each panel of the carpet. The series diodes of Figure 2 are also typically included in the carpet array, however, if it is too difficult or costly to include the diode and only one or two carpet switches will be closed at any one time, the diodes may be omitted from the individual carpet panels and a single diode placed in series with each of the column lines as indicated by the "*" on the column input lines to switch array 106 in Figure 3.If there is only one diode in each of the column lines instead of the individual diodes in series with each switch in the carpet there is the possibility of the console circuitry of misidentifying one or more of the switch closures if at least two switches in one column and at least one switch in an adjacent column are closed simultaneously, thus the limit of one person on the carpet at a time when external diodes are used. When the individual diodes are incorporated in the switch matrix in series with each of the switches there is no situation were the monitoring circuitry will not be able to identify which switches are closed. Thus, with the included diodes the maximum number of switch closures permitted without any false identifications is equal to the total number of switches in the matrix (i.e. 48 in a 8x6 matrix), and the maximum number of switch closures in a matrix with external column diodes to avoid false identifications is limited 3 regardless of the size of the switch matrix.

By incorporating the first switch matrix 106 in a carpet, the playing field of the learning device is large enough for a team of people to participate in the learning exercise by selectively walking or standing on various panels of the carpet after the instructor/trainer has programmed the second switch matrix 108 on the console to create, for example, a mine field in mode A, or a path across the carpet in mode B. In any of these situations the group that is participating is trying to navigate the carpet with the least soundings of the alarm in the shortest possible time. This sort of device has been discovered to aid in the training of problem solving skills, in improving team work, and has proven useful in developing better managers/leaders.

While only a rectangular matrix of switches of 8x6 has been discussed in this application, the invention is not limited to that size and configuration. Larger or smaller sizes could be used as required for the particular application. Additionally, other configurations could also be utilized, such as one involving concentric circles of switches with each circle sub-divided into two or more segments with a single segment in the center, or any other configuration that meets the requirements of the particular application. Also, despite the fact that the monitoring circuit discussed above was designed using a collection of open- and closed-collector inverters and negative logic, the present invention could also be implemented using various other components and positive logic without any loss of performance.The design of the monitoring circuit of the present invention is therefore not limited to the circuit that was selected to illustration the operation of the present invention and the present invention of the monitoring circuit is only limited by the scope of the appended claims.

The general concept of the printed circuit switch of the present invention is to provide an array of switches that will be approximately h the size of a same size array of toggle switches. The individual switch of the present invention includes the two pole portions of the switch formed on a printed circuit board and the switch closure portion being an external standard electronic jack that is inserted to extend through the printed circuit board to provide closure between the two poles on the printed circuit board.

The following is a description of the making of a switch of the present invention wherein the dimension of the central hole is selected to accommodate a standard 'banana" jack as the external jack that will be used to provide switch closure.

Initially a printed circuit board that is laminated on one or both sides with cooper foil is selected. For the inventors' intended purpose for the printed circuit switch, a 3.2mm (0.125in.) epoxy glass board laminated on both sides with 35 microns (1 ounce per square foot) cooper foil was selected.

The desired hole pattern is shown in Figure 4.

Initially, l.Omm (0.040in.) pilot holes B are drilled with a central hole A of 4.089mm (0.161in.) centered between the two pilot holes so that the center of each of holes B is substantially located on the outer circumference of hole A along a first diameter line 1 of hole A. The diameter of hole A has been chosen to accommodate a standard banana jack. Additionally, two additional holes C are drilled along an extension of diameter line 2 of hole A with diameter lines 1 and 2 being substantially perpendicular to each other. Since holes C are spaced apart from the circumference of hole A, one skilled in the art would realize that the order in which holes A and C are drilled is strictly a matter of choice.

Since holes C are to serve as vias in the finished switch, their diameter is selectable to best accommodate the process of plating through the holes.

Given the selected material and it's selected thickness for the applicants' purpose, holes C were selected to have a diameter of l.Omm (0.040in.).

After all of the holes are drilled, both sides of the printed circuit board are cleaned and approximately 5 microns (o.2 mils) of copper is deposited over both surfaces, the edges and through the hole A, B and C.

Following the deposition step, holes B are redrilled to 1.65mm (0.065in.) to remove the copper deposited in those regions. Thus, the copper layer on the inner surface of hole A is split into two portions on either side of holes B.

Both surfaces of the printed circuit board are again cleaned, a resist pattern is applied to both surfaces by a standard procedure, additional copper is electroplated on the exposed copper surfaces to a thickness of about 25 microns, followed by plating with tin-lead to an additional thickness of about 10 microns.

The plating resist is then removed and the newly exposed copper is etched away with tin-lead acting as the etch resist. Next, the board is ref lowed to melt the tin-lead into a solder alloy, it is coated with a solder mask if desired, and the final board outline is sheared or routed.

Figure 5 shows a plan view of a portion of one side of a printed circuit board 3 having the two pole pieces of a switch of the present design. In this view the two poles 4 and 5 of the switch can be seen. As described in the process above, both sides of the printed circuit board will have a similar pole pattern with poles 4 and 5 on one side of the printed circuit board connected to poles 4 and 5, respectively, on the other side of the printed circuit board by plated through via holes C and the partial inner edge of hole A.

Figure 6 shows a side view of a typical banana jack 6. Banana jack 6 has a lower jack portion that consists of a set of spring fingers 7 that are each connected to the other with a threaded portion 8 above for receiving a internally threaded insulative cap 9 that is shown in dotted outline. In many other applications a wire will be connected to the threaded region of the banana jack 6 and extend out from a hole in the proximate end of cap 9. That is not necessary in the present application. In the present application banana jack 6 is only intended to be used to effect electrical contact between the two pole portions 4 and 5 (the two plated through sides of hole A) to make switch closure. To do so, the lower portion of banana jack 6 is inserted into hole A with the individual spring fingers 7, 7', 7", etc.

each making contact with a portion of the interior of hole A. Thus, when so inserted, fingers 7 being interconnected one with the other caused an electrical path to exist between poles 4 and 5 of the printed circuit switch of the present invention.

While the embodiment discussed above includes vias C and pole pieces on both sides of the printed circuit board which could have been omitted, these have been added to extend the life of such switches. Vias C have been provided in case the repeated insertions of banana jack 6 into hole A causes damage to the hole wall and the pole pieces otherwise on one side of the printed circuit board become disconnected from those on the other side of the board, electrical connection will remain through the associated vias. Similarly, the inclusion of poles 4 and 5 on both sides of the board aids in the anchoring of the plated through surfaces of hole A to lessen the possibility of that plating from becoming dislodged and peeling away. More practically, the hole wall and pole pieces are selectively plated with a metal alloy which is harder or more abrasion resistant than copper (i.e. tin/lead, etc.).

While only one printed circuit board switch of the present invention has been discussed above in a printed circuit board, as many switches of the present design may be included in a single printed circuit board with those switches each being produced simultaneously using the same procedures discussed above. Additionally, even though the above discussion has been directed to the use of a standard banana jack for the switch of the present inventions one skilled in the art will easily see other options for the closure device of the present invention. Therefore the full scope of the present invention should be limited only by the scope of the following claims.

Claims

CLAIMS:

1. A method for producing a printed circuit switch for closure with a separate conductive plug having a conductive shaft that includes spring fingers that can be compressed with the spring finger having a first diameter when the fingers are fully expanded and a second smaller diameter when the fingers are compressed, said conductive plug to be inserted thereinto for such purpose, said method comprises the steps of:: a. selecting a printed circuit board having conductive foil adhering to at least one side thereof; b. drilling a first hole of a third diameter through said printed circuit board wherein said third diameter is intermediate said first and second diameters; c. drilling a pair of second holes of a substantially smaller fourth diameter than said third diameter on opposite sides of said first hole at substantially opposite ends of a diameter line of said first hole and with the center of each of said pair of second holes located substantially on the edge of said first hole; d. deposit conductive material at least on the exposed sides of said first and second holes through said printed circuit board;; e. remove the conductive material deposited on at least a portion of said second holes after completion of step d. leaving at least a portion of the conductive material deposited on the sides of said first hole to make electrical contact with said conductive plug when inserted into said first hole to make electrical contact to each side of said first hole in the finished printed circuit switch; f. selectively etch said conductive foil on the surface of said printed circuit board to form the poles of said switch; wherein said conductive material deposited on the sides of said first hole make electrical contact with said conductive plug when said plug is inserted into said first hole to make electrical contact to each side of said first hole in the finished printed circuit switch.

2. A method as in claim 1: further includes the step of: g. drilling a pair of third holes of a substantially smaller fifth diameter than said third diameter spaced apart from opposite sides of said first hole along an extension of a second diameter line of said first hole with said second diameter line being substantially perpendicular to said first diameter line prior to step d.; wherein step d. further includes depositing conductive material on the sides of said pair of third holes; and wherein the poles formed in step f. surround said pair of third holes.

3. A method as in claim 1 wherein said third diameter is approximately 3 to 4 times larger than said fourth diameter.

4. A method as in claim 2 wherein said third diameter is approximately 3 to 4 times larger than said fourth and fifth diameters.

5. A method as in claim 1 wherein step e. includes the step of: h. redrilling said pair of second holes to a larger diameter to remove the conductive material deposited on the sides of said holes in step d.

6. A printed circuit switch comprising: a conductive plug having a conductive shaft that includes spring fingers that can be compressed with the spring finger having a first diameter when the fingers are fully expanded and a second smaller diameter when the fingers are compressed; a printed circuit board defining: a first hole of a third diameter wherein said third diameter is intermediate said first and second diameters; a pair of half circles of a substantially smaller fourth diameter than said third diameter on opposite sides of said first hole at substantially opposite ends of a first diameter line of said first hole and extending outward and away from the center of said first hole; and first and second conductive switch poles on at least one side thereof with each of said first and second poles located on opposites sides of a second diameter line of said first hole substantially perpendicular to said first diameter line and extending into and along opposite sides of the sides of said first hole; wherein closure of said first and second conductive switch poles is effected when said conductive plug is inserted into said first hole.

7. A printed circuit board switch as in claim 6 wherein said printed circuit board further defines: first and second conductive switch poles on both sides thereof and interconnected to the corresponding poles on the opposite of said printed circuit board by the portion thereof that extends into and along opposite sides of the sides of said first hole; and a pair of third holes of a substantially smaller fifth diameter than said third diameter through said first and second conductive switch poles, respectively, and spaced apart from opposite sides of said first hole along an extension of said second diameter line of said first hole with each of said third holes being plated through.

8. A printed circuit board switch as in claim 6 wherein said third diameter is approximately 3 to 4 times larger than said fourth diameter.

9. A printed circuit board switch as in claim 7 wherein said third diameter is approximately 3 to 4 times larger than said fourth and fifth diameters.

10. A learning or game device for use by two or more persons comprises: a first switch array means having a plurality of switches in a particular geometric configuration, each switch having an open and a closed position and each switch in said first switch array means for selective closure by a first person; a second switch array means having the same number of switches as said first switch array means and of the same geometric configuration as said first switch array means with each switch in the second switch array means being in a corresponding location to a switch in said first switch array means, each switch having an open and a closed position and each switch in said second switch array means for selective closure by at least one person other than said first person; mode selection means for manually selecting between first and second operating modes;; scanning means for simultaneously scanning switches in said first and second switch array means being in corresponding locations within each array; detection means for producing a signal when the first mode is selected and corresponding switches in both said first and second switch array means are in the closed position, or when the second mode is selected and one or more switches in said first switch array means is closed and the corresponding one or more switches in said second switch array means is open; alarm means for sounding an alarm in response to said signal produced by said detection means.

11. A learning or game device for use by two or more persons as in claim lo wherein said first and second switch array means each have a rectangular configuration that is organized into X rows and Y columns with array means having X times Y switches and each switch in each array is connected between a different combination of rows and columns with a first terminal of Y switches connected to each of said X columns and a second terminal of X switches connected to each of said Y rows so that a particular row and column designation identifies the location of a single switch in each of said first and second switch array means where X and Y are each integers of at least one.

12. A learning or game device for use by two or more persons as in claim 11 wherein each switch in said first and second switch array means further includes a diode in series therewith to limit the flow of electrical current through any switch that is closed to those times when the column to which it is connected is scanned by said scanning means.

13. A learning or game device for use by two or more persons as in claim 11 wherein: each switch in said first switch array means further includes a diode in series therewith to limit the flow of electrical current through any switch that is closed to those times when the column to which it is connected is scanned by said scanning means; and each column in said second switch array means further includes a diode in series therewith to limit the flow of electrical current through any switch connected to the column that is closed to those times when that column is scanned by said scanning means.

14. A learning or game device for use by two or more persons as in claim 10 wherein each switch in said first switch array means includes: a conductive plug having a conductive shaft that includes spring fingers that can be compressed with the spring finger having a first diameter when the fingers are fully expanded and a second smaller diameter when the fingers are compressed; a printed circuit board defining: a first hole of a third diameter wherein said third diameter is intermediate said first and second diameters; a pair of half circles of a substantially smaller fourth diameter than said third diameter on opposite sides of said first hole at substantially opposite ends of a first diameter line of said first hole and extending outward and away from the center of said first hole; and first and second conductive switch poles on at least one side thereof with each of said first and second poles located on opposites sides of a second diameter line of said first hole substantially perpendicular to said first diameter line and extending into and along opposite sides of the sides of said first hole; wherein closure of said first and second conductive switch poles is effected when said conductive plug is inserted into said first hole.

15. A learning or game device for use by two or more persons as in claim 11 wherein said first switch array means includes: a plurality of conductive plugs each having a conductive shaft that includes spring fingers that can be compressed with the spring finger having a first diameter when the fingers are fully expanded and a second smaller diameter when the fingers are compressed; and printed circuit board means defining said plurality of switches in the desired rectangular array with each individual switches defined thereon in said X rows and Y columns; wherein each switch defined by said printed circuit means includes: a first hole of a third diameter is intermediate said first and second diameters; a pair of half circles of a substantially smaller fourth diameter than said third diameter on opposite sides of said first hole at substantially opposite ends of a first diameter line of said first hole and extending outward and away from the center of said first hole; and first and second conductive switch poles on at least one side thereof with each of said first and second poles located on opposites sides of a second diameter line of said first hole substantially perpendicular to said first diameter line and extending into and along opposite sides of the sides of said first hole; wherein closure of said first and second conductive switch poles is effected when said conductive plug is inserted into said first hole.

16. A learning or game device for use by two or more persons as in claim 11 wherein said scanning means includes: oscillator means for producing a pulse train of a selected frequency; and cyclic pulse generating means responsive to said oscillator means and connected to said columns of each of said first and second switch array means for cyclically applying a pulse to the corresponding ones of each of said columns in turn.

17. A learning or game device substantially as hereinbefore described with reference to or as shown in the accompanying drawings.

18. A method of producing a printed circuit board substantially as hereinbefore described with reference to the accwanying drawings.