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ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING Electronic game room. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Beginner radio amateur Today's issue is dedicated to electronic games. Continuing to study in the radio club, now, say, in the conditions of a city camp, you can make the proposed designs and create a small game library. Its visitors and participants in the games can be both club members and everyone. The same game library can be organized at school in the summer. Or maybe you will go with her to visit the nearest camp and entertain the resting guys there. WHO IS STRONGER? There are many sports and games that test strength and endurance. If there is no suitable room and shells for their implementation, use the services of electronics. To compete in strength, for example, will help the simplest device, the scheme of which is shown in Fig. 1. It will replace the carpal expander.
There are few details in the device. A DC amplifier is assembled on the VT1 transistor, to the input terminals of which (XT1 and XT2) sensors are connected - they are metal tubes mounted on pieces of wooden rods. The dial indicator PA1 is included in the collector circuit of the transistor. In the initial position, the transistor is closed, since its base is connected through a resistor R2 to the emitter, and there is no bias voltage on the base. But now you have the sensors in your hands. Between the sensors, which means between the clamps, the resistance of a part of your body is now included, which, of course, also depends on the humidity of the palms. Through this resistance, the base of the transistor is connected to the minus of the power source. The stronger you squeeze the sensors, the larger the surface of the palms comes into contact with the metal (it must be cleaned to a shine and degreased), the less resistance between the clamps, the greater the current in the transistor base circuit. Accordingly, the current through the pointer indicator also changes. The maximum current flowing through the emitter junction (base-emitter section) of the transistor is limited by resistors R1 and R2, and the current through the indicator is limited by the trimming resistor R3. Transistor - any of the MP39-MP42 series with the highest possible current transfer coefficient. Fixed resistors - MLT-0,25 or MLT-0,125, trimmer - SP, SPO or another type. Pointer indicator - with a full deflection current of the pointer of 100 μA - 1 mA and a frame resistance to direct current of not more than 1 kOhm. Amplifier parts are mounted in a housing (Fig. 2), which can be ready-made or self-made (from any material). An indicator, a power switch and clamps are attached to the front panel. The rest of the parts are located inside the case. Opposite the axis of the tuning resistor, a hole for a screwdriver is drilled in the side wall of the case. The power supply (3336 battery) is mounted on a removable bottom cover.
The sensors are connected to the terminals with a stranded installation wire in insulation. Set up the device like this. First, the trimming resistor engine is brought up according to the scheme (the resistor is closed). Having squeezed the sensors as much as possible, they notice the deviation of the indicator arrow. If it goes beyond the final division of the scale, move the resistor slider down and select its position so that the arrow deviates by about a third of the scale. If the arrow barely deviates even with the resistance of the resistor removed, you need to replace the resistor R2 with another one, with a resistance of 2,2; 3,3 or 4,7 kOhm. In the process of competition, such a position of the resistor engine is found in which only the strongest of the competitors can deflect the indicator needle to the final division of the scale. WHO QUICKLY? A person who, after giving a command, is able to immediately execute it, is said to have a good reaction. It helps to achieve good results in sports. For example, a sprinter who starts very close to the referee's whistle or the starting pistol is more likely to finish first. But a good reaction is necessary not only for an athlete. A driver, a test pilot, an astronaut, and a policeman should have this quality. It is necessary for people of dozens of professions. Do you want to check what kind of reaction you and your comrades have? This is easy to do with the proposed game. It consists of two signal lamps, two buttons and other parts shown in the diagram (Fig. 3). After switch SA1 is supplied with voltage, the referee gives the command. Each of the players tries to press the buttons faster: SB1 - for the first player and SB2 - for the second. If the first player does it faster, the HL1 lamp will light up, if the second one, HL2. This is why it happens.
When the SB1 button is pressed, the voltage of the GB2 battery is applied to the base of the transistor VT2 through the button contacts, the resistor R2 and the lamp HL1. Transistors VT1, VT2 open, and the lamp HL1 lights up, because it is connected through the collector-emitter circuit of the transistor VT1 to the battery. In this case, of course, the voltage between the emitter and the collector of the transistor VT1 decreases - before the button was pressed, it was equal to the voltage of the power source, and now it is about 1 V. The partner who pressed his button a little later than you will not be able to light the HL2 lamp, because the voltage on the collector of the open transistor VT1 is not enough to open the transistors VT3 and VT4. After releasing the button, wait for the next signal from the referee to try again to get ahead of the opponent. The winner can be considered the one who, out of ten attempts, lights his lamp more times. The lamps must be taken for a voltage of 3,5 V and a current of 0,26 A. Lamps with a smaller (but not with a large!) Current will do, but then you will have to replace the resistors with others with a higher resistance. Transistors take any of the MP25, MP26 series, if possible with the same current transfer coefficient. Power switch - toggle switch TV2-1, battery - 3336. Buttons - any design, such as bells. The body of the structure should be counted on them. Resistors - MLT - 0,125 or MLT - 0,5. Mount the details of the game (except for the battery and buttons) on the board (Fig. 4). Installation is simple, but when performing it, you must follow a certain sequence. After installing the mounting racks, connect the two lowest ones with a jumper. Then solder the resistors, fix the switch, screw the lamps into the pre-drilled holes in the board, connect the threaded parts of the lamps with conductors to the switch output, and the remaining lamp contacts to the corresponding mounting racks. Solder the transistors last.
Attach the board with parts to the front wall of the case (Fig. 5).
To do this, drill a hole in the wall for the switch, two holes for the lamps and two more holes for screws with a diameter of 3 mm (pass the screws through these holes and fix the board on them inside the case). Close the lamps with transparent caps. Attach buttons to the top of the front wall. Drill holes under them in advance and pass the conductors from the button contacts inside the case. Place the battery in a convenient location inside the case. It is also desirable to attach it with a metal bracket to the removable bottom cover. It's time to test the game in action and adjust it. But first, as usual, carefully review the entire installation and compare it with the diagram. Then turn on the power switch and press the SB1 button. The HL1 lamp should light up. Release the button and press SB2. Now HL2 will light up. Check the accuracy of the design. Press the SB1 button and, without releasing it, the SB2 button. If at the same time the HL2 lamp starts to light up gradually (it may flash immediately, extinguishing the HL1 lamp), you should select a resistor R2 with a lower resistance (or increase the resistance of the resistor R1). Next, press the SB2 button, followed by SB1. The HL2 lamp continues to burn. If the HL1 lamp also starts to light up, then you have reduced the resistance of the resistor R2 too much. It is necessary to choose its resistance more precisely. You can do otherwise. Pressing the SB1 button first, measure the voltage on the HL1 lamp with a voltmeter, then, releasing the SB1 button and pressing SB2, do the same on the HL2 lamp. By selecting the resistance of one of the resistors, achieve equality of the obtained voltages (their values should not be more than 3 V). Moreover, if you need to change the voltage on the HL1 lamp, select the resistance of the resistor R2 (the lower its value, the greater the voltage on the lamp). It is likely that by using transistors with the same current transfer coefficients, no adjustment will have to be done. In rare cases, such an effect as the spontaneous ignition of one (and even less often two) lamps is also manifested. This is eliminated by connecting between the base and the emitter of transistors VT1 and VT4 resistors with a resistance of 510 Ohm ... 1 kOhm. Having achieved a clear homemade work, close the bottom cover and invite your friends to compete in the speed of reaction. WHO WILL JUMP HIGHER? There is a small board hanging on the wall with three metal contacts located at different heights and signal lamps (there are also three of them, but one - HL3 - is painted red). From the board stretches a flexible wire with a probe at the end. The participant in the game (the guys should be about the same height) takes the probe in his right hand and bounces, trying to touch one of the contacts with the probe. If he succeeds, the corresponding lamp flashes on the scoreboard. The winner is the one who can light the red signal lamp by touching the highest located EXNUMX contact. The "stuffing" of this homemade product is shown in fig. 6. Metal contacts are shown as sensors E1-E1, and the probe with which they are touched is indicated by the letters XPXNUMX. Each of the contacts is connected to a cascade consisting of an oxide capacitor, a limiting resistor and a composite transistor.
It is worth touching the probe, say, contact E1 - the capacitor C1 is instantly charged and the composite transistor VT1VT2 opens. The HL1 lamp lights up. When the probe stops touching the contact, the lamp continues to burn for some time, since the capacitor, like a battery, has managed to charge from the source and now feeds the emitter junction circuit of the composite transistor, which remains open for some time. The duration of the glow of the lamp practically depends on the capacitance of the capacitor and the resistance of the limiting resistor. Other cascades work the same way. Resistors can be MLT - 0,25 or MLT - 0,125, capacitors - K50-6 or others, with a capacity of 100 ... 200 microfarads, transistors - any of the MP25, MP26 series with a static current transfer coefficient of at least 20, lamps - for voltage 3,5 V, battery - 3336 or three galvanic cells connected in series 373 (with such a power source, the duration of the structure will increase significantly). There is no power switch as the game draws very little current in its initial state. But during long breaks in work, the battery should be disconnected. Signal lamps are placed on the scoreboard near "their" contacts, and the remaining elements are mounted on the inner wall of the scoreboard. Parts can, of course, be mounted on a printed circuit or circuit board. A ballpoint pen with a metal rod is suitable as a probe - a stranded installation wire in insulation (length - 2 ... 3 m) or an ordinary plug is soldered to it. Establishing the game comes down to the selection of limiting resistors. By connecting the probe to contact E1, select a resistor R1 of such resistance at which the voltage on the HL1 lamp will be equal to 2,5 ... .3 kOhm By smoothly moving the variable resistor slider, the desired result is achieved, and then the resulting total resistance is measured and a resistor with such or possibly close resistance is soldered in place of R1. Similarly, resistors R2 and R3 are selected. Labyrinth In this game, the most attentive, quick-witted and calm one wins. It is these qualities that are needed in order not to get confused in complex moves and messages leading to the cherished goal - the "room". The path to it must be passed with a metal probe, moved along the paths of the labyrinth. It is impossible to touch the walls of the labyrinth - the control lamp will immediately flash and an audible signal will sound. The winner is the one who reaches the "room" with fewer touches. A drawing of the labyrinth is shown in fig. 7. Of course, you can make any other drawing with a more intricate interweaving of paths leading to the goal. But remember that with the complication of the pattern, the complexity of manufacturing the structure increases.
It is most expedient to use for the labyrinth, say, fiberglass or getinaks, covered on one side with foil. Then it is enough to cut grooves in the foil with a sharp knife or a special cutter - and the labyrinth is ready. But the likelihood that you will be able to get such material is small. Therefore, you will have to stock up on a plate of aluminum or duralumin of the dimensions indicated in the figure, apply labyrinth tracks to the surface with an awl, drill holes in the tracks as close to each other as possible, saw through the gaps between them with a file and saw off the edges of the tracks so that they become even. Track width can be 4...5 mm, plate thickness 1...1,5 mm. Put the finished metal plate on the smooth surface of the strip of insulating material, such as getinax, and attach to it with screws and nuts. If there is good glue, then the plate can be glued to the base. Attach a metal petal (or a small strip of tin from a can) to the plate and solder an insulated mounting wire to it. The probe is a piece of copper wire with a diameter of 1,5 ... 2 mm and a length of 10 ... 12 cm. One end of it must be cleaned of enamel insulation and sharpened with a file so that it becomes semicircular and it is convenient to lead along the paths of the labyrinth. To the other end, solder a stranded installation wire in insulation 50 ... 60 cm long, and then pull a piece of rubber or PVC tube onto the probe so long that the probe end protrudes 5 ... The touch signaling device (Fig. 8) is assembled on four transistors. The first two (VT1 and VT2) work as an electronic key that connects the control lamp HL1 to the power source when the terminals XT1 and XT2 are closed (in other words, when the probe connected to the XT1 terminal touches the labyrinth walls to which the conductor from the XT2 terminal is connected). The generator is assembled on the other two transistors - it is connected in parallel with the HL1 lamp. As soon as the lamp flashes, voltage will appear on it. The oscillator immediately starts to work, and a sound is heard from the dynamic head BA1. Its tone depends on the capacitance of the capacitor C2 and the resistance of the resistor R2.
Touching the walls of the labyrinth with a probe can be instantaneous. Will the signaling device feel it, will the lamp have time to flash? In the simplest case, when voltage is applied to the lamp through the probe, it would hardly have had time to glow. But this option is provided in the device, and a kind of time delay is introduced into the signaling device. It consists of a capacitor C1 and a resistor R1. Voltage is applied to this chain through the probe. Even a short circuit of the clamps is enough for the capacitor C1 to charge up to the voltage of the battery GB1. And then it starts to discharge through the resistor R1 and transistors VT1, VT2. And although the probe has already moved away from the walls of the labyrinth, the lamp is on, and a sound is heard from the dynamic head. The duration of the delay is short - less than a second. Transistors VT1 and VT2 take the MP25, MP26 series with a current transfer coefficient of at least 20. In addition to those indicated in the diagram, in place of VT3 you can install other low-power transistors of the npn structure (for example, MP37V, MP38) with a current transfer coefficient of at least 35, and in place of VT4 - a transistor from the MP39 - MP42 series with a current transfer coefficient of at least 45. Lamp HL1 - for a voltage of 3,5 V and a current of 0,26 A. But it is better if you install a lamp with a lower current consumption, then the transistor VT2 will work in an easier mode and heat up less when the probe touches the walls of the labyrinth for a long time. Resistors - MLT - 0,125 or MLT - 0,5, capacitor C1 - K50 - 6, but another one with a capacity of 100 ... 200 microfarads is also suitable. Moreover, the larger its capacity, the longer the duration of the delay, and hence the glow of the lamp after touching the walls of the labyrinth with the probe. Switch SA1 - toggle switch TV2 - 1, battery - 3336, but another 4,5 V source is also suitable, designed for the desired load current - up to 0,3 A (for example, three 373 elements connected in series). Mount the details of the signaling device on the board (Fig. 9). Having marked the board blank, cut a hole in it for the dynamic head diffuser, drill holes for the control lamp and switch, and install these parts on the board (the lamp must be screwed into the hole). Then install mounting racks on the board, solder resistors and capacitors to the racks. Connect the lamp contacts to the stand and the switch, respectively, and then solder the dynamic head leads to the board parts. Finally, solder the transistor leads to the posts. Make sure that the transistors are exactly in their places in accordance with the circuit and wiring diagrams.
The mounted board must be fixed in the housing (Fig. 10) with a removable bottom cover. Drill holes for the switch and the lamp in the upper wall of the housing, cut a hole opposite the head diffuser and cover it with a decorative cloth or plastic grille. The board with parts can be attached to the top wall with screws, but it will be securely held by a nut screwed over the wall onto the switch body.
Install the clamps on the top wall, and place the battery inside the case on any of the walls or attach it with a metal bracket to the bottom cover. The connections between the board, the battery and the clamps are made with a stranded installation wire in isolation. Setting up the alarm is easy. After applying power to the SA1 switch, temporarily connect the emitter and collector of the transistor VT2 together and thus connect the generator and the HL1 lamp to the power source. The lamp should light up, and a sound will be heard from the dynamic head. If this does not happen, then an error was made in the installation. Eliminate her. Then remove the jumper between the emitter and the collector of the transistor VT2, and close the clamps together. The lamp may light up brightly, as well as when connected directly to the battery. Such brightness, of course, is not needed, and it should be reduced in order to avoid excessive current through the VT2 transistor and its heating. To do this, turn on a variable resistor with a resistance of 1 or 2,2 kOhm in series with the resistor R3,3 and, moving its slider, set the voltage on the lamp to 2,5 ... 3 V. Then measure the resulting total resistance (variable resistor and constant R1) and solder a resistor with this resistance instead of R1. If the brightness of the lamp when the clamps are closed is insufficient, you need to slightly reduce the resistance of the resistor R1. FIND "MINA" In films about the Great Patriotic War, you have often seen how sappers work. With headphones on their heads, they carefully check every meter of ground with a long rod with a ring - a sensor at the end. As soon as there is a barely noticeable change in sound - stop! A mine is hidden in this place. And in peaceful days there is work for sappers, because the land has not yet been cleared everywhere of disguised ammunition. No, no, yes, and they are found in the most unexpected places, even at the bottom of rivers and ponds, deposits of shells. And sappers again and again have to engage in single combat with death ... With your friends and you can become "sappers" for a while. You can search for "mines" ... in the room. They can be, for example, thin lids from cans or circles of roofing iron with a diameter of 6 ... 8 cm. And they must be hidden under a carpet, thin rugs or paths. It remains to make a "mine detector". Since the "mines" will lie shallow from the surface of the search field, we will assemble the simplest design, the schematic diagram of which is shown in Fig. 11. There is only one transistor in our "mine detector" - a generator of electrical oscillations of sound frequency is assembled on it. B1 is a sensor, which is a coil wound on a permanent magnet. The sound frequency depends on the capacitance of the capacitors C1-C3 and the inductance of the sensor coil. The oscillations of the generator are fed through the capacitor C4 and connector X1 to the headphones BF1. The variable resistor R2 sets the operating mode of the transistor, which means the highest sensitivity of the "mine detector".
The device is powered by a GB1 battery, the voltage is supplied through the SA1 switch. As long as there are no metal objects near the sensor B1 of the "mine detector", a sound of a certain tone is heard in the headphones. But it is worth bringing the sensor, for example, to a small steel plate, as the tone of the sound changes. The closer the transducer is to the metal, the greater the change in the pitch of the sound. On this basis, they find the location of the "mines". As a sensor, it is convenient to use a capsule from headphones TON - 1, TON - 2 (Fig. 12) or the like with a winding resistance of at least 1 kOhm. But the capsule will have to be modified - to remove the membrane. The transistor must be MP39B, MP42B with a current transfer ratio of at least 35 (otherwise the generator will not work). Fixed resistors - MLT - 0,5, variable - SP - 1. Capacitors - type MBM. Headphones - TON - 1, TON - 2 or similar. Power switch - toggle switch TV2 - 1, power supply GB1 - battery "Krona", connector X1 - any type with two sockets for headphone plugs.
Parts, except for the sensor, power supply and connector, must be placed on a small board (Fig. 13).
On fig. 14 shows the body of the device. A board is attached to its top panel. To do this, you can use the nuts for fastening the switch and the variable resistor. Put a plastic control knob on the resistor axis. Install the connector on the top panel, and drill a hole for the conductors from the sensor on the side wall. Attach the power battery to the removable bottom cover opposite the capacitors C2 and C3. Connect the battery terminals to the parts on the board with insulated stranded mounting conductors. You can solder the ends of the conductors directly to the terminals of the Krona battery or use a block from the same battery (of course, unusable) and solder the terminals to it, observing the polarity - the negative wire from the switch to the terminal of the block with a smaller diameter, and the positive wire to the terminal with bent petals. This makes it easier to change the battery.
Now check the operation of the assembled part of the device. Place the headphone capsule on the table next to the case with the cover up and connect it with insulated conductors to the board parts in accordance with the diagram. With the power off, connect a milliammeter in parallel with the contacts of the toggle switch (for a C20 type device at the limit of 3 mA) and set the current to about 2 mA with a variable resistor R1. Mark this position with a dot on the top panel of the case, affixed against the notch on the control knob. Turn off the milliammeter and use the toggle switch to power the generator. Headphones plugged into the X1 jack will hear a medium-pitched sound. Bring a massive iron object, such as pliers, to the cap of the sensor capsule. You will immediately notice that the sound coming from the phone has changed its tone. When moving the variable resistor slider to the left according to the scheme, the tonality of the sound increases, but at the same time its volume decreases. After setting the resistor knob to a position where the sound is still audible, again bring the same object closer to the capsule cover. The "mine detector" has become more sensitive and will detect metal at a distance of 10 ... 15 mm from the sensor - first, the tone of the sound in the phones will increase, and then (with the further approach of the object to the sensor) the sound will disappear. This position of the control knob can also be marked on the front panel of the case. It remains to make a search bar. Disconnect the capsule from the generator and attach it with a magnet down to a disk cut, for example, from a thin getinax (Fig. 15, a) or other insulating material. Attach the disk with the sensor to a wooden handle (Fig. 15,b), the lower end of which is cut at an angle. This design will imitate a real mine detector.
Install the generator on the handle. It is more convenient to do this: attach the removable bottom cover of the generator housing to the handle with screws, and screw the housing itself to it. You can do otherwise - fix the case on the handle with metal corners screwed to the side walls of the case. In this case, first lead out through the hole in the side wall the stranded mounting conductors in insulation of such a length that they can be connected to the terminals of the sensor capsule. After attaching the housing to the handle, tie the conductors in several places with electrical tape, and connect the ends of the conductors to the sensor leads. Turning on the generator and inserting headphones into the connector, bring the disk with the sensor closer to the lid of the can. Notice at what distance between them the tone of the sound will change (set the sensitivity of the "mine detector" near the maximum). It should be 8 ... 10 mm. So, the "mine detector" is ready. You can start the game. Under the carpet or rug, hide the lids from cans in several places and invite the "sapper" (he, of course, should not see the preparatory work). Using the device, the "sapper" must detect the maximum number of "mines" and indicate their locations. The disk with the sensor is allowed to be driven along the carpet (or rug). Whoever finds all the "mines" the fastest wins. Of course, the game can be played according to other rules - come up with them yourself with your friends. Another variant of the device for holding competitions to search for "mines" is also possible, based on inductive coupling. In this case, you will also need a "mine", but already electronic, and a receiver. "Mina" - a miniature transmitter (there may be several of them), operating at an audio frequency, is masked in the ground on the street or indoors. Each such "mine" (Fig. 16) is a multivibrator made on transistors VT1, VT2 and operating at a frequency of approximately 1000 Hz.
A power amplifier based on a transistor VT2 with an inductor L3 as a load is included in the emitter circuit of the transistor VT1 of the multivibrator. An electromagnetic field of sound frequency is formed around it. This field captures the receiver sensor (Fig. 17) - coil L1. Audio frequency oscillations from it are fed to the amplification stage on the transistor VT1. The amplified signal is heard through the BF1 headphones. The sensitivity of the receiver is such that the sound of a "mine" can be heard at a distance of up to a meter.
The transistors of the multivibrator and receiver can be of the MP39-MP42 series with the highest possible current transfer coefficient, the power amplifier transistor - of the MP25, MP26 series. The "mines" coil is wound on a frame with an internal diameter of 8 and a length of 30 mm and contains 800 turns of PEV wire - 1 0,1. A rod of the same dimensions made of 400NN ferrite is inserted inside the frame (600NN is possible). The receiver coil contains 3000 turns of PEV wire - 1 0,12, wound on a rod with a diameter of 8 and a length of 80 ... 100 mm from 400NN ferrite. The power source is a 3336 battery, but the "mine" can also work from a single element 373, 343. Details of the "mines" are mounted on a board (Fig. 18), which, together with a power source, is mounted inside the case of possibly smaller dimensions. An inductor is also placed there. The switch is fixed on the side wall - it is used immediately before the "mine" is disguised and after it is discovered.
The details of the receiver, except for the inductor, push-button switch and headphones, are also mounted in a small case and strengthen it near one of the ends of a wooden lath about a meter long. A switch is installed on the rail near the housing, and a coil is attached to the opposite end of the rail (Fig. 19). Headphones can be connected directly to the appropriate points on the receiver or through a connector and plug. It should be noted that headphones can be both high-resistance, such as TON - 1, and low-resistance, for example, miniature TM - 2A. The first of them allow you to get more sensitivity, but less volume, and the second, on the contrary, - more volume, but less sensitivity. By selecting the resistor R1 in the receiver, the maximum sound volume is achieved.
In conclusion of the review of the designs of electronic games, we note that the germanium transistors of the MP series recommended for use in them may not always be in the stocks of the radio circle. Instead, silicon transistors can be used, for example, the KT315 (npn) and KT361 (pnp) series. Naturally, with such a replacement, you will have to select resistors in the base circuits of transistors. Author: V.Polyakov, Moscow
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