DC-DC converter is the core of Brushless motor

DC-DC converter is the core of Brushless motor

220V AC voltage is rectified and filtered DC voltage to be 320V or so, add to the power module input. Single DC-DC module maximum output voltage is generally +48 V, +60 V DC to get the output voltage, the method must be used module in series. Design uses two PH600S280-28 DC-DC module (to +30 V output) through the series to get +60 V output voltage, fast recovery diodes D1, D2 is the protection devices in series, requiring D1, D2 reverse voltage greater than twice the rated output voltage power supply, power supply rated current greater than twice the output current, the forward voltage drop should be as small as possible. Because it is in series with two power supply module power supply system, in a limited package to complete the design will be difficult, and some program using two modules in series to complete the design package, namely the design of two separate 30V power supply, then an external series constitute the +60 V power supply system. Design through the rational allocation of space, power up and down in the lid of each installation of a DC-DC module to heat the metal shell as a means of compact design and installation of technology to the entire power system packaged in a smaller space, so that the whole power supply size, weight greatly reduced cross-sectional area of ​​only 6 × 9 inch 2, to achieve a small size high-power integrated power system design.

Brushless motor drive circuit

Brushless motor drive circuit, if the distributor in accordance with the decision of the distribution ring, to control the motor windings of each phase is turned on or off, so that the motor steps required to drag the rotor magnetic potential of rotation rotation step, the step angle is only two, that the whole or half-step work work, step angle motor structure has been determined. If the request brushless motor with a smaller step angle, higher resolution, or to motor vibration, noise and other reasons, you can switch each input pulse, the only change in the nominal winding corresponding part of the motor synthetic Ci potential step angle rotation only part of the rotor to run each step, only part of the step angle. Here, the winding current is not a square wave, but the step-wave, current rating is the step-input or the removal of the current into the number of steps, the rotor turned on with the same number of times a step away from the corner, this would be a step subdivided into a number of step angle driving method, known as the sub driver. In other countries, for the step system, mainly two-phase hybrid brushless motor and the corresponding sub-driver. However, at home, the majority of users of "niche" is not particularly aware of, but rather that the subdivision is to increase the accuracy, is not the case, mainly to improve the electrical breakdown of the operating performance. As the sub-drive to accurately control the motor phase current, so the drive must have very high technical requirements and process requirements, the cost will be higher.

In order to brushless motor phase current control to achieve the sub-brushless motor step angle of the goal, it was designed for a very wide range of brushless motor drive circuit segments. With the development of micro-computer, especially the emergence of single-chip computer, the breakdown for the brushless motor drive is made easier. Currently, brushless motor drive circuit segments are single-chip computer control of most, they constitute a block diagram shown in Figure 4. Microcontroller according to the requirements of step angle calculated for each phase winding by the current value, and output to digital to analog converter (DPA), by the DPA to digital conversion to the corresponding analog voltage, applied through the phase ring distributor amplifier circuit, amplifier circuit to control each phase winding of the corresponding current to achieve brushless motor breakdown.