● Tip for RC helicopter, RC airplane, and RC drone enthusiasts.

[laodan]

          When using a regulator or converter (whether step-up or step-down, as shown in the picture) instead of a direct battery to supply small amounts of power (usually 4.8V to 8.4V) for controlling servos in RC helicopters, airplanes, and drones, there is a critical factor you must consider: electromagnetic interference (EMI). This phenomenon is occasionally blamed for sudden unintended acceleration in automobiles, though manufacturers are rarely willing to admit it. Unless created by a deity, no electronic device is perfect. Correcting one issue inevitably gives rise to another unwanted side effect. Every electronic device that draws electricity generates unwanted noise. Consequently, we live blissfully surrounded by spaces filled with emissions from various electrical and electronic equipment. In a sense, modern humans live amidst invisible garbage. Because electronic noise is extremely difficult to control perfectly, users must find a compromise..

          Commercially available ESCs with built-in BECs (Battery Elimination Circuits) are manufactured to suppress noise as much as possible and shield signal lines to minimize its impact, but they are not flawless. The closer they get to perfection, the more exorbitant the price becomes. Therefore, as a fellow RC hobbyist, I recommend using an ESC without a built-in BEC rather than one with it. When installing a separate BEC, you can position it to best suit the specific characteristics of your aircraft's fuselage. You should place the BEC, ESC, and receiver as far apart from each other as possible. The ESC output signal is vulnerable to this noise. Twisting the ESC output signal wires (usually white and black) together can help mitigate this effect. Receivers are extraordinarily sensitive to the noise generated by BECs because they are designed to detect signals traveling through the air from the transmitter. If they are close together, interference occurs 100% of the time. The signal becomes distorted, causing the aircraft to momentarily move on its own without any stick input. If it is a helicopter, it will nose-dive straight into the ground. In helicopters, the tail servo usually malfunctions. When the aircraft starts spinning out of control, panic sets in, and your precious equipment gets destroyed. You might suspect a faulty gyro and replace it. But that is not it. Nine times out of ten, it is caused by signal interference from the noise at the BEC power output. As shown in the illustration(photo), the wires are wrapped a few times around a ferrite ring magnet at the output section to reduce noise, and the wires themselves are twisted. However, adding more magnetic rings or winding the wires further may reduce noise, but it creates an unnecessary electromagnetic field. This is also undesirable. This is because a magnetic field forms around any current-carrying conductor, and an even stronger magnetic field is generated when the wire is shaped into a loop. There is no benefit to this.

          If EMI from the BEC followed a consistent pattern, we could establish a diagnostic standard and find a remedy. However, because it varies depending on the battery's state of charge, temperature, and humidity on that specific day, this unpredictable interference is downright frustrating and drives up one's blood pressure. When installing a converter, you must design the layout to keep it at a distance from both the receiver and the ESC. This is the single most critical factor that RC users must keep in mind.▮