A pleasant surprise on the tree, no doubt, will be shimmering two-tone flower. This fixture uses seven two-color LED diodes, which on a circuit Board arranged in the form of petals of a flower. They alternately glow green, then red. Located in the center of the flower led also two-tone, but at a time when the rest of LED diodes light up, for example, in green, it glows red, and Vice versa. This is a simple the device is designed as a separate module, which can be placed on the tree as decoration or to be mounted in any toy or souvenir.
Module shimmering multicolored flower is a conventional switch, which voltage in turn is fed to two groups of LEDs. Schematic diagram of the device shown in the figure.
The proposed device, which is executed just on a single chip and two the transistors can be divided into three functional blocks: a master generator, control unit and readout scheme.
Master oscillator that generates pulses of management made on the chip IC1, which is connected in an astable multivibrator. The frequency switching of the multivibrator is determined by the resistance value of the resistor R1 and capacitance value of the capacitor C1. The switching pulses from the output of master generator (the output of IC1/3) are served on a base of transistors T1 and T2, with which provide a direct voltage to the corresponding groups of LEDs.
When forming the output of the chip IC1 (pin IC1/3) continuous the sequence of positive and negative control pulses the transistors T1 and T2 are alternately deny it. Thus, when the vehicle is unlocked the positive momentum of the transistor T1 through his open transition "collector-emitter", the anodes of the respective group dual LEDs D1-D7 will be connected through resistors R5 and R7 to the positive power source that will lead to the illumination of these diodes is one of the colors. At the end of the Manager pulse the transistor T1 will be closed again and the lights will go out. When the vehicle is unlocked a negative pulse of transistor T2 through an open transition "collector-emitter" to the positive power supply through resistors R6 and R8 will be connected to the anodes of the second group dual LEDs D1-D6. As a result, these the LEDs will glow a different color. At the end of the pulse the transistor T2 once again closes and the lights go out. The admission on the bases of the transistors the sequence of control pulses from the master oscillator (IC1) make the sequential illumination of the diodes until then, until the power is turned off. Located in the center of the flower two-color led D7 is included so in a time when the rest of the diodes light up in green, it glows red, and Vice versa.
All the details of the module shimmering flower placed on a circuit Board the size of 68x42 mm. the printed circuit Board pattern shown in the figure.
The location of parts on the circuit Board of the device are shown in the figure.
Instead of two-color LEDs can be used with any single color LED diodes. In this case, one two-colour diode just replaced two conventional LEDs of different colors, combining their cathodes. However, it is necessary to make the appropriate changes in the pattern of the PCB, drilling additional holes.
Indicated on the diagram of p-n-p transistor VSV (T2) can be replaced, for example, domestic transistor type CTV. Instead of n-p-n transistor VSV (T1) can install domestic type transistor KTM.
Installation of elements on the PCB should be carried out in the usual manner, have you first need to solder the jumper and socket circuits, resistors then and the capacitor C3, transistors and capacitors C1 and C2. After that you can set on the circuit Board of the module LEDs. In the process of mounting elements special attention should be paid to the correct Pinout transistors, electrolytic capacitors and LEDs. In this case LEDs in determining the destination of the findings should not be guided by them length. In any case, two-colour LED diodes middle pin is the common cathode. At the same time the color matching of the remaining two conclusions can monitor using a normal battery voltage of 4.5 V. For this enough to the minus of the battery to connect the output of the cathode, and the positive through resistor 470 Ohm alternately connect the remaining conclusions. So by the way, you can determine which one is the anode of the red led, and a green anode. Upon final installation of the LEDs on the PCB cost you can be guided by the symbols shown in the figure arrangement of elements.
After checking the correct place in the module connect the power supply voltage 9 V. Since the current consumed by the device is about 60 mA, then to power the module flashing flower it is recommended to use either two connected in series with flat batteries 3336L (2x4,5 V), or mains rectifier 9 In providing a corresponding current.
Assembled without errors from the healthy parts, module shimmering flower is not need additional mending. If desired, the selection of values the resistance of the resistor R1 and the capacitance of the capacitor C1 can change the frequency flashing LEDs.