Generalities about radio control cars encoders and more

When focusing on radio control cars details, you can always find out what this is all about to move onto the next level. The signal generator has a specific function. You can encode the position of a potentiometer in short periods of time:

ü  In a transmission of 30ms (max) control several independent channels.

ü  To make it as efficient on the information it carries.

ü  Send a sync signal to be interpreted in the decoder.

ü  Modular RF stage in both AM and FM signals without producing spurious or take up much bandwidth.

ü  Simple circuit and low cost.

ü  It easy to introduce pre-programmed control signals.

The reality is that the channel used to send many channels is one and the data travels in a bit stream. That is cool information channels sequentially. This means that real time is not as intended, but many times per second, how often? In the worst case, for a 30ms frame, we need each cooling channel 33.3 times per second, and in a typical case with a 20ms frame refreshes each channel 50 times per second. It is enough if we think, but for some cases, these times are not enough.

A stable multi vibrator with quality radio control cars transistors will do. In electronics, an stable multi vibrator is a state that has no stable, which means it has two states "quasi-stable" between commuting, staying at each one time. The switching frequency depends, in general, charging and discharging of capacitors. Among its many applications include the generation of periodic waves (clock generator) and pulse trains.

The operation of this circuit is as follows:

      By applying the supply voltage, the two transistors start driving as their bases receive positive potential through resistor R-2 and R-3, but as transistors will not be exactly identical, by the very manufacturing process and the degree of contamination of the semiconductor material, a lead sooner or faster than the other.

      Suppose that TR-1 is leading the first. Under these conditions the radio control cars voltage at its collector will be close to 0 volts, so that the C-1 will begin charging through R-2. When the voltage on C-1 reaches 0.6 V, TR-2 will begin to drive, passing the low level output (voltage close to 0V).

From here the sequence is repeated indefinitely, depending on driving times and blocking of each transistor and R-3/C-2 R-2/C-1 relations. These times are not necessarily the same, so you may get different duty cycles acting on the values of these radio control cars components.