Electronic speed controller schematic diagram

#Electronic speed controller schematic diagram full

That means there are 1,296,000 electrical cycles per minute (36,000 rpm x 6 winding phases x 6 poles = 1,296,000), or 21,600 cycles per second. The example motor has 12 poles, so the controller must switch the FETs 36 times per revolution of the shaft (6 north poles x 6 steps per magnetic rotation).

#Electronic speed controller schematic diagram full

The six coil combinations needed for a full magnetic rotation must be repeated for every north pole in the motor. An outrunner motor with 12 poles that has a Kv (rpm per volt) of 1,500 and is powered with 24 volts (6S Li-Poly) will spin at 36,000 rpm (24 x 1,500 = 36,000). LetвЂ™s do a bit of math to get an idea of the incredible activity going on inside the ESC. But high-power electronic switches-known as Metal Oxide Semiconductor Field Effect Transistors (MOSFETs, or FETs for short)-can turn on and off in a fraction of a second and are ideally suited for this application. Mechanical switches are simply incapable of the task. The timing and duration of these connections is critical-and unbelievably short. The ESC uses electronics to connect any of these wires to positive or negative, to achieve one of six possible combinations that results in an electromagnetic field in a precise location in the motor. LetвЂ™s call the three motor wires вЂњA,вЂќ вЂњB,вЂќ and вЂњC,вЂќ and their вЂњfreeвЂќ ends, those that stick out of the motor, are connected to the ESC. A Delta-wind motor generally has nearly twice the Kv of a similar motor with a Y-wind. ItвЂ™s not much of a jump from there to understand the name for the Y-wind. Delta wind gets its name from the Greek symbol. The two wind termination types are known as a Delta and a Y-wind. The type of connection does affect the torque curve of the motor. The controller doesnвЂ™t care which is used the windings need only to be connected. There are two ways this connection is made one is the Delta, or D-wind, and the other is the Y-wind. ItвЂ™s important to understand that these windings are connected at one end inside the motor. It uses three sets of copper windings to push and pull permanent magnets attached to the shaft inside the power plant. LetвЂ™s look at each of these more closely.Д«efore we go too far, letвЂ™s make a few things clear about the operation of a brushless motor. The most accessible way to describe the operation of the ESC is to break it down by functional sections.ДЄ brushless ESC uses a microprocessor to manage the operation of field-effect transistors (FETs), using information from a rotor position circuit. The usual explanation is something along the lines of, вЂњItвЂ™s a mystery!вЂќ The reason for a component failure is a mystery to most involved, but understanding a bit more about brushless systems can go a long way toward helping a hobbyist enjoy outstanding reliability in an electric-powered airplane or helicopter.ДЄ brief description of the role of the brushless Electronic Speed Control (ESC) is that it must accurately make and break connections between the three input leads of the motor and the power source to drive the rotor magnets around the arc of the power plant. Mysterious events are often attributed to mystical causes, and brushless power systems are about as mysterious as things get in RC. As seen in the November 2010 issue of Model Aviation.