Currently, there are a lot of schemes with running lights on the Internet. In our article we will look at the simplest circuit, assembled on two popular microcircuits: the 555 timer and the CD4017 counter.
We will assemble according to this diagram (click on it to enlarge):
The scheme is not very complicated as it seems at first glance. So, to assemble it, we need:
1) three resistors with a nominal value: 22 KiloOhm, 500 KiloOhm and 330 Ohm
2) NE555 chip
3) CD4017 chip
4) 1 microfarad capacitor
5) 10 Soviet or Chinese LEDs at 3 Volts
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Currently, most microcircuits are produced in the so-called DIP package. DIP from English – Dual In-line Package, which literally means “double-row assembly”. The pins of the microcircuits in the DIP package are located in opposite directions from each other. The pin spacing is generally 2.54mm, but there are also exceptions. Depending on how many pins the microcircuit has, the housing for this microcircuit is called. For example, the 555 chip has 8 pins, hence its package is called DIP-8.
I marked the so-called “keys” in red circles. These are special marks with which you can find out the beginning of the marking of the microcircuit pins
The first pin is located right next to the key. Counting goes counterclockwise
This means that on the NE555N chip the pins are numbered as follows:
The same applies to the CD4017 chip, which is manufactured in a DIP-16 package.
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The pins are numbered from the lower left corner.
We collect our running lights. On the breadboard they look something like this:
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And here is the circuit in action:
The whole circuit works in this way: a rectangular pulse generator is assembled on a 555 timer. The pulse repetition rate depends on resistor R2 and capacitor C1. Next, these rectangular pulses are counted by the CD4017 counter chip and, depending on the number of rectangular pulses, outputs signals to its outputs. When the counter in the chip overflows, everything starts all over again. The LEDs blink in a circle as long as there is voltage on the circuit.
Keep in mind that there are a lot of analogues of the 555 and CD4017 microcircuits. There are even Soviet analogues. For the 555 timer it is KR1006VI1, and for the counter chip K561IE8.
The homemade LED running lights circuit presented in this article is based on a fairly popular one. Up to 12 programs of various lighting effects are stored in the program memory, which can be selected as desired. This includes running fire, running shadow, growing fire, and so on.
This automatic lighting effects machine allows you to control thirteen LEDs, which are connected through current-limiting resistors directly to the ports of the ATtiny2313 microcontroller. As mentioned above, 11 different independent combinations of light patterns are hardwired into the microcontroller’s memory, and it is also possible to sequentially cycle through all 11 combinations once, this There will already be a 12th program.
Button SA3 allows you to switch between programs.
Using the SA1 and SA2 buttons, you can control the speed of movement of the lights or the flickering frequency of each LED (from constant glow to light flickering). It all depends on what position the SA4 switch is in. When the switch SA4 is in the upper position according to the diagram, the speed of the running lights is regulated, and in the lower position the flickering frequency is adjusted.
When installing LEDs in a line, you should follow the same order as numbered in the diagram from HL1 to HL11.
The ATtiny2313 microcontroller is clocked from an internal oscillator with a frequency of 8 MHz.
(1.1 Mb, downloaded: 3,657)
One option for using solid-state light sources for decorative purposes is LED running lights. There are a lot of ways to make this simple device. Let's look at some of them.
On the Internet, the most common one is a simple “old-fashioned” circuit using a meter and a generator (Figure 1).
Picture 1
The operation of the circuit is extremely simple and clear. The generator is built on the basis of a pulse timer, and the counter performs its main function - it counts pulses and produces the corresponding logical levels at its outputs. LEDs are connected to the outputs, which light up when a logical one appears and, accordingly, go out at zero, thereby creating the effect of running lights. The switching speed depends on the frequency of the generator, which in turn depends on the values of resistor R1 and capacitor C1.
The names of the microcircuits are Soviet, but they have easily accessible imported analogues. If you need to increase , then to increase the current you need to connect them through buffer transistors, because The meter outputs themselves have a fairly modest load capacity.
To obtain more complex effects, the circuit must be built on a microcontroller (hereinafter referred to as MK). Although there are many circuits of running lights on a microcontroller on the Internet, built on ordinary logic, implementing different sequences of LED lighting, their use is unjustified and impractical these days.
The schemes turn out to be more cumbersome and expensive. The MK allows you to flexibly control individual LEDs or their groups, store many lighting effect programs in memory and, if necessary, alternate them according to a predetermined sequence or by an external command (for example, from a button). In this case, the circuit turns out to be very compact and quite cheap.
Let's consider the basic principle of constructing a circuit of running lights on LEDs using a microcontroller.
For example, let's take the ATtiny2313 chip - an 8-bit MK costing about $1. The simplest circuit can be implemented by directly connecting LEDs to the I/O pins (Figure 2). These MK pins are capable of providing a current of up to 20 mA, which is more than enough for indicator LEDs.
The required current value is set by resistors connected in series with the diodes. The current value is calculated using the formula I=(U power -U LED)/R. The MK power supply and reset circuits are not shown in the figure so as not to clutter the circuit. These circuits are standard and are performed in accordance with the manufacturer's recommendations in the Data Sheet. If it is necessary to precisely set time intervals (the duration of ignition of individual LEDs or a complete cycle), you can use a quartz resonator connected to pins 4 and 5 of the MK.
If there is no such need, you can get by with a built-in RC generator, assign the freed pins as standard outputs and connect a couple more LEDs. The maximum number of LEDs that can be connected to this MK is 17 (Figure 2 shows an option for connecting 10 LEDs). But it is better to leave one or two outputs for the control buttons, so that you can switch the running fire modes.
Figure 2
That's all for hardware. Then everything depends on the software. The algorithm can be anything. For example, you can store several modes in memory and set the repetition interval for each, or connect two buttons: one to switch modes, the other to adjust the speed. Writing such a program is a fairly simple task even for a person who has never worked with a microcontroller before, but if you are too lazy or don’t have time to study programming, and really want to “revive” a running fire on LEDs, you can always download ready-made software.
New Year's schemes - automatic lighting effects that are easy to assemble with your own hands for a novice radio amateur
Good afternoon, dear radio amateurs!
Welcome to the website ““
Time flies very quickly. Before you know it, the New Year is just around the corner, it’s time to sum up the results of the year you’ve lived, isn’t it a shame, looking back, for the days you’ve lived? And the upcoming holiday needs to be somehow diversified with new ones New Year's homemade products, assembled with your own hands to the delight of family and friends.
Today we will look at several New Year's schemes lighting effect machines for holiday decorations, simple, not containing scarce parts and easy to assemble.
First scheme:
Miniature Christmas tree with “running fire”
This LED Christmas tree will decorate your holiday table and will definitely delight all your friends and acquaintances:
A rectangular pulse generator is assembled on transistors VT1 and VT2, and electronic switches are assembled on transistors VT3 and VT4, which switch groups of LEDs. The LEDs are located on the printed circuit board in the form of a Christmas tree. The frequency of the generated pulses depends on the ratings of resistances R2, R3 and capacitors C1 and C2 (the higher their rating, the lower the frequency of the generator).
Transistors VT3 and VT4 are connected to the generator outputs through current-limiting resistors R5 and R6, respectively. Pulses from the generator alternately open the transistors. When transistor VT3 is open, LEDs HL1-HL3, HL10-HL14, HL18, HL19 light up. And when transistor VT4 is open - HL4-HL9, HL15-HL17, HL20. Switching them creates the effect of running fire. Power is supplied from a 9 volt battery.
All parts are mounted on a single-sided printed circuit board:
Parts can be used of any type, LEDs - with low current consumption, instrumentation type.
Second scheme.
She's not exactly second. Based on this circuit, using one widely available microcircuit, several transistors and LEDs, you can assemble a large number of different automatic lighting effects.
Such lighting effect machines will become a decoration for the New Year's holiday, a wonderful New Year's gift.
The basis of this circuit is a three-phase generator assembled on a microcircuit K561LA7(in extreme cases, it can be replaced with K561LE5).
What is it like? microcircuit K561LA7 and its full analog CD4011A:
Scheme of a three-phase generator on the K561LA7 microcircuit:
The resistances of the resistors and the capacitance of the capacitors in such a circuit are equal: R1=R2=R3, C1=C2=C3.
This is how a generator works. At the moment the power is turned on, all capacitors are discharged, there is a logical zero at the inputs of the microcircuit 1-2, 5-6, 8-9, and a logical one at the outputs 3, 4, 10. Capacitors begin to charge through resistors. Although the values of resistors and capacitors are the same, due to the variation in the parameters of real parts, some capacitor will charge faster. Let’s say capacitor C1 is charged first, a logical one appears at input 1-2 of the microcircuit, and a logical zero appears at output 3, respectively. Capacitor C2, not having time to charge, will begin to discharge through resistor R2. In the meantime, capacitor C3 will have time to charge to a logical one and naturally a logical zero will appear at output 10 - capacitor C1 will begin to discharge through resistor R1. You can follow the further path of operation of the microcircuit yourself by analogy. Thus, at outputs 1-2-3 there is a periodic change from logical zero to logical one. Now it is enough to connect transistor switches with LEDs to outputs 1-2-3 and we will get lighting effects machine:
The fourth element - DD1.4 - is not used, and its inputs (pins 12-13) are connected to the “+” power supply.
Transistor switches are assembled on transistors VT1-VT3, each of which turns on and off the corresponding garland of LEDs. Resistors R4-R6 limit the current through the LEDs. The letters A-G indicate the connection points for LED garlands of a different type for the machines described below.
All resistors are any, small-sized, transistors of the KT315 series with the letter designations A-G. LEDs must be of the same type and the same color. On the PCBs below, the LED anodes must be soldered to square pads.
First lighting effects machine"Triangle".
The LEDs on the board of this machine are located along the contour of a triangle:
When the generator operates, pulses of positive polarity are sequentially formed at its outputs, which alternately open the transistors, resulting in the effect of “lights” moving around the perimeter.
Second lighting effects machine"Propeller".
The circuit is no different from the previous one, and the “propeller” lighting effect is ensured by the appropriate arrangement of LEDs on the board:
By experimenting with the placement of LEDs on the board, you can achieve many other lighting effects.
Third lighting effects machine"Snowflake".
The device creates the effect of a falling snowflake, which is achieved by sequentially lighting (with rotation) three “concentrically” arranged garlands of single-color LEDs.
This differs from previous schemes in the number of LEDs in the garland (four instead of three) and in the absence of current-limiting resistors R4-R6 in connection with this:
The garlands are connected to the corresponding points A-B on the diagram.
PCB diagram:
Appearance of the machine:
Fourth lighting effects machine“Running Lights.”
This scheme is no different from the “Snowflakes” scheme - there are also 4 LEDs in a garland, but they are located differently. This design creates an original effect of “running lights” in the form of a rotating light line:
Appearance of “Running Lights”:
Fifth lighting effects machine"Star".
The machine creates the effect of a star emitting rays.
The difference between this circuit and the previous ones is in the number of LEDs and the way they are turned on:
PCB drawing “Star”:
And this is what the “Star” lighting effects machine looks like:
Sixth lighting effects machine“Running bug.”
The sequentially flashing LEDs of this device create the effect of an insect moving its legs, while its abdomen and head glow constantly.
Scheme of the “Running Bug” garland:
Garlands A-B-C imitate the paws, and garland D (constantly glowing) imitates the abdomen and head.
Printed circuit board of the “Running Bug”:
Appearance of the “Running Bug” light effects machine:
Seventh lighting effects machine"Running Wave"
Consecutive flashes of several garlands, each of which consists of three LEDs arranged in the form of a reverse tick, create a “traveling wave” in this design.
