After an intense semester, I reopen this new section dedicated to the drones; in this occasion we will learn to assemble a circuit with a small buzzer anti-lost for any model of drone or radio control.
This little hack will help us so that the handset issues intermittent beep provided that the same leds blink; i.e. When is the battery running low, or when the drone lost the connection to the control station.
In this example I will use my SyMa X 8, but the following circuit should be compatible with any drone; the only difference between models will lie in welding point to connect the collector transistor that we are going to use.
To develop this small project, we will need a couple of resistors: an of 100Ω (R1), and another of 3.9KΩ (R2); a piezo buzzer as light as possible and operate between 3-5V (in my case I have chosen one of 1.5 grams and 30mA of consumption); a NPN transistor BC548; and finally cable, Tin, and welder; to understand that application has the transistor in our circuit in a simple way, visualize the following channel video of Oliver Nabani.
In my case I have implemented it with resistors SMD to reduce the final size of the module, and do not rule out in the future to lighten it even more by changing the transistor by one SMD; also It is possible to do it with ceramic resistances more easily, and that's that I've done the following diagram with them so that everyone can develop it without the added problems of the micro-welding.
First of all We weld the collector of the transistor to the negative pin of the buzzer; It is important to look at the curvature of the transistor that can be seen in the previous scheme, and that will allow us to distinguish their pins at a glance.
Then We weld both resistances between, in the case of work with ceramic resistances will not have greater complication that weld them, And then isolate the welding; However with resistances SMD We must help with some type of support and/or forceps, due to its small size; also should be noted that It is vital to solder them both up and down to avoid that you end by breaking the welding.
Once welded both two together, and prior to the extraction of the chosen support, We will proceed to solder a cable between them; in particular the one that appears in Black in the schematic shown above.
At this point, We weld resistance 3.9KΩ or R2 on the positive side of buzzer/buzzer, weld that also a cable; in this case the positive circuit, highlighted in color Red in the Schematic of the project.
Then We weld resistance of 100Ω, or R1 at the base of the transistor; that we can identify as the pin of the Middle of your package.
To mount our module, We must weld a third wire to the emitter of the transistor; preferably color Brown in the schematic, to differentiate it from the other negative which already we soldier previously a black wire.
Now we open our drone and desatornillaremos the flight controller, to identify where are we going to weld each of the wires of the module we just manufacture; first look for the point of connection of the positive LEDs, and we will solder the cable that comes from the positive our buzzer.
The other end of the Brown wire We must weld it in the battery negative of our drone; I have located it in the on/off switch of the same, to avoid to the extent possible to solder directly on the flight controller of the quadricoptero.
At last We weld the second negative, represented black in the schematic; Some models just weld it to the negative of the same circuit of the LEDs, but in the case of Syma X 8 this will produce a constant sound during the whole flight as shown in the next video, Since the leds lower luminosity to the Flash, but they do not go completely.
The solution to this problem is por welding cable to the negative of the tiny state of the flight controller red led (Since this if it shuts), located in the small SMD transistor collector that I can see in the image below; only estañaremos the end of the cable and the pin of the transistor, Finally together, remove the soldering tip, and wait until the union is cool if single.
We can already now check operation our module buzzer by connecting the battery to the flight controller; already after the test We'll remove the sticker buzzer and close our drone, and with extreme caution we will a flight test to verify that everything works correctly.
In the upcoming tutorials of this new section We enter the world of the drones, We will learn to improve them, and we will know the basic principles of its operation, as well as the necessary hardware to assemble one from scratch.
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