Simple flasher for two LEDs
Virtually every novice radio amateur collected multivibrator transistors. This scheme does not require a large number of components and has a completely understandable principle for beginners. However, the work of the finished product, despite the simplicity, is quite interesting and fascinating. Especially if you include two different colored LEDs in the circuit.Similar flashers are used in many fields of human activity. The most striking example of the use of the scheme is electronic flashing beacons on a service vehicle (ambulance, police). Symmetric multivibrators based on the structure described below can also be found in other radio equipment, for example, in acoustic sirens and alarms. They are used in the simplest children's toys.
The device and the principle of operationThe scheme of the educational multivibrator, the stage-by-stage assembly of which is described below, consists of two transistors, capacitors and LEDs.Additionally, depending on the voltage of the used power source, current-limiting resistors are added to the design. The flashing light on two transistors works as follows. In the first phase, one of the transistors is in the open state, as the current from the symmetric arm of the multivibrator arrives at its base. Due to this, one LED is lit and the opposite capacitor is charging. At this point, the first phase of the cycle ends. Then, when the capacitor is fully charged, the current stops flowing through it. As a result, the transistor closes and the first LED goes out. Instead, the second flashes. This happens because the capacitor gives up the accumulated energy. This opens the second transistor and the LED lights up. At the same time, the opposite capacitor is charging. Then the cycle is repeated according to the algorithm described above.
Required materials and radio componentsTo assemble a classic 12 V LED multivibrator with your own hands, you will need the following radio components:
- KT361 transistors - 2 pieces (KT315 but you have to change the polarity of the power,capacitors and light-emitting diodes);
- electrolytic capacitors with a capacity of 47-50 microfarads and a rating of 16 V - 2 pieces;
- 3 V LEDs - 2 pieces (preferably multicolored);
- 300 Ohm resistors - 2 pieces;
- 27 kΩ resistors - 2 pieces;
- wires for connecting parts.
Step-by-step assembly of the multivibratorFirst recommended collect all the necessary radio components and lay them on the table as shown in the diagram. If soldering is carried out on the board, then this step can be skipped. When assembling a multivibrator with a mounted installation, the sequence of actions will be as follows.
Sticking edge on chipboard
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