# The Electronic Switch of Windings of a Standard BLDC Motor
## 3 Experimental Verification and Results
For each motor model there are points of efficiency intersection, where it is optimal to switch the windings' connection circuits from a reduced gear to an increased one (similar  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Star**} & \multicolumn{6}{c}{**Delta**} \\ \hline  & **1** & **2** & & **3** & & **4** & & **5** & & **6** & \\ \hline
**24 volt** & **Speed** & **Current** & **Speed** & **Current** & **Speed** & **Current** & **Speed** & **Current** & **Speed** & **Current** & **Speed** & **Current** \\ \hline MIN & 30 & 18 & 50 & 20 & 70 & 34 & 45 & 19 & 80 & 24 & 110 & 53 \\ \hline
1 & 50 & 19 & 100 & 24 & 250 & 114 & 100 & 24 & 250 & 39 & 300  
to switching the gearbox in a car). Microprocessor connected to an ESC controller makes this operation automatically like an automatic transmission of a car keeping the maximal efficiency through the whole range of speed conditions. In practice, it is not necessary to use all six possibilities of windings' connection circuits, but it is enough to choose options No. 1 or 2, and 4 or 5 to cover a wide dynamic range, which cannot be reached by a motor without the electronic switch, see the bar chart as a part of Figure 11. If such a control of the electronic winding switch is taken into count, the overall performance ensures high efficiency withing the wide range of the BLDC motor operation, which any standard BLDC motor would not be capable of. When an electronic winding switch with BLDC motors having 24-36 or more poles is considered, the number of the win can be increased. As a result, there will be a greater number of options for controlling the parameters of the motor. The effectiveness of the application of this approach can also be demonstrated in one example. If the winding scheme No.1 is assumed for this demonstration purposes to represent a standard fixed scheme from the manufacturer, its speed range would be in the range of (30 up to 325) RPM. It is clear then that the original scheme (No.1) cannot operate in the speed range of (110 up to 1750) RPM corresponding to the range of scheme No.6. That would be unattainable with a standard implementation. From the other side, if the winding scheme No.6 is assumed to be a fixed scheme from the manufacturer, then at low speeds there will be large heat losses and unstable synchronization according to BEMF. Heat losses increase the temperature inside the motor, and due to the compact size of this one, they can lead to exceeding the permissible values. Excessively high temperature inside the motor may thus cause negative effects on the life cycle of the motor windings, or rather their insulation, as well as may lead to reduction of the magnetic field inside the motor by affecting the rotor magnets' strength; therefore, reducing operating temperature in general extends the engine life cycle. The proposed approach with the electronic switch of the BLDC motor windings enables the motor operation within the range of (30 up to 1750) RPM with an optimal torque, depending on the ratio of the current and rotation speed, and low heat losses.