ELECTRONIC “DICE”

The device:

 

1 — front panel; 2 — a decorative overlay; 3 — the led (20 PCs); 4 — PCB; 5 —Z-shaped bracket installation switch (s1 steel plate); 6 — mount the PCB and bracket to the body (M3 bolt with nut, 2 sets.); S1 — main switch; S2 — mode switch

Most of these devices uses the classic output for digital indicators. However, it creates a lot of problems, in particular due to the fact that there the count starts from 0, not 1, as is customary in the gaming dice. Bulky it turns out the schema and selecting ranges of accounts. So I had to stay on the positional display. But applied chip delirium only As binary bits and thus has 16 output channels. What about the numbers from 17 to 20? The classical solution is to put another decoder cumbersome and uneconomical, and the outputs of the CMOS counter simply does not pull two address input “oak” TTL chips. What if you use a D3 decoder “for the second time”? Thanks to the element D1.1 we have the MSB of the addresses, both in direct and in reverse video Now just using the transistors VT1, VT2, enable the appropriate group of LEDs. depending on the range of numbers. Three of these groups: HL 1-6 work at 0 in the fifth binary digit, HL 17-20 — when 1, well, on the HL 7-16 meals can be served constantly. The magnitude of the current through the LEDs is determined by the resistors R6, R8, R9. The device he is about 7 mA. This ensures sufficient brightness of display and at the same time does not overload even hook up a low powered (transistor-transistor logic with Schottky barrier) chip К155ИДЗ. When using the new generation LEDs to heterostructures of the mentioned resistance of the resistors can be increased two or three times.

This mode can be selected by switch S2. As soon as the account reaches the “prohibited” 7 or 21 points via R11 to the input of the cascade on the VT3 enters the log. 0. The signal is inverted and fed to the reset input of the counter. In addition to the logic functions cascade on the VT3 performs another function. The fact that one of the problems when working together CMOS and TTL circuits is not sufficiently high voltage is logical 1 last. Here it is amplified to almost the supply voltage. The logics of this node there is another feature: in the accepted system of decoding the number 21 is “mirrored” by the number 5, which can lead to premature reset of the counter. Therefore, a 20-sided mode on VT3 through R10 is served inverted fifth level of the counter. Because of this, when the numbers that are less than 16, the transistor opens and the reset input, the counter will log.0. regardless of other signals. During starting (when the button is pressed S1) LEDs of the selected range are highlighted slightly by current pulses, “running” on them That allows you to verify the health of the scheme and all of the LEDs.

 

When using the dual-mode e-cube, the following error is possible, work in a 6-sided mode when you need a 20-sided. The result may be that powerful ballista categorically refuse to penetrate the armor of the Marines. Therefore, the required effective display 6-sided mode. No tricks with digital indicators can not eliminate the error absentmindedly. In the proposed design display 6-sided mode led HL7, which is his kind of visual limitation included range of reference. Not to notice that instead of one of the desired burn from two LEDs, is impossible, and OTO — another advantage of the adopted positional display system. Not to short-circuit to earth will. 7D3, it is separated from the switch by a diode.

 

 

A circuit diagram of a combined “6-sided” and “20-sided” electronic “dice” for games

 

 

Topology of the printed circuit Board

 

Voltage regulator 5V (chip DА1) mounted directly on the Board. Because of this, to supply the device, you can use practically any network adapters with an output voltage in the range 9 — 12V, the benefit of consumption current does not exceed 80mA. Acceptable option — 2 — 3 battery 336 which are connected in series. But in this case the design will need to enter the power switch.

 

About the parts: transistors VT1, VT2 can be any of series KT361, КТ203, VT3 blocking — n-p-n structure, KT315 series, КТ301, КТ312. Chip К176ЛА7 interchangeable on K561LA7. D3 — 155 or 1533-series. Such changes do not require changes to the wiring circuit Board. Only К1533ИДЗ may be in a more narrow case, but the Pinout is the same.

 

However, it may be that the acquisition of the needed chips will be difficult. Almost all sold now in stores “logic” — 1988 — 1992 release, and these stocks are low. It remains to replace the chip to other, similar purpose. So, as the D2 you can use the chip К176ИЕ1 — simple 6-bit binary counter. As a D1 — a chip with three elements. In this case, the element D1.2 is eliminated, the signal of the start to one of the inputs D1.3. The Application Of D1.2 is good because it still produces pulses of the multivibrator. But the counters will work in this shortened version of the schema.

 

Remind about need of observance of rules concerning mounting of semiconductor devices: CMOS chips should be stored wrapped in foil, low voltage soldering iron with a grounded tip. This is especially true of circuits in early development, when designers were reluctant to install protection elements due to the lower performance In applications of solder or something suspicious chips use the socket. LEDs, particularly in a plastic housing, soldering should not be closer than 10 mm from the body, preferably using an additional heat sink.

Switch S2 – any three sets of changeover contacts. In the present device applied П2К 2 buttons with dependent fixing. It contacts the pins on one side are shortened. Button S1 — type KM 1-1, or the like. The selection of colors of LEDs (for example, the first 6 of a different color), readers can make at its discretion. Capacitors C3, C4 — ceramic of any suitable dimensions.