The quartz QZ1 of the preceding receivers which set the work frequency is not on the market any more. It is replaced
by a locking phase loop allowing the free choice of an unspecified frequency on the band used, either the 41, or the 72 MHz. The step between channels is 5 kHz, giving us 101 frequencies in 72 MHz and 41 in 41 MHz. In practice, the RX19 ` scans ` on the 2 frequencies chosen by the user. The first is called a Normal Frequency (Fn) and he other, a Safety Frequency (Fs). In fact, one does not take precedence over the other, except that when turning the power on, the RX19 starts by using Fn. In addition, it will use whichever signal of either Fn or Fs it will receive clearly.
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To be considered as " correct ", the received signal must have a " PCM signature ", identifying the transmitter’s owner. This code is a number selected between 0 and 255, inserted in the sequence. It should be noted that we do not use PCM (Pulse Coded Modulation) for the servo’s sequence. In our humble opinion, it only brings useless and even harmful complications, the signal to be transmitted being much more complex. We remain faithful to the PPM (Pulse Position Modulation), a simple and effective method which allows easy insertion of our code. We call this new R/C technique, " PPCM " modulation. The figure above shows the principle used. The great advantage of PPCM is to remain completely compatible with existing receivers, the decoders being sensitive only to the front signal wave, they do not take any account of the position of the rear signal wave and are therefore completely unaware of the inserted code. One can thus, with the same transmitter, control a RX19 (with PPCM) or a RX17 (without PPCM)!
In a normal receiver, such as a RX17 or a RX18, the decoded signal arrives directly at the servos. If the signal is good, all is perfect. If it is bad, so be it and the servos go anywhere and the plane does aerobatics! Let us note how in one such receiver, a fault detector highlights an anomaly only after it has occurred. Obviously! In this case, the servos reacted... and made an inopportune movement... and the plane...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
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The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
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In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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