Issue link: https://resources.mouser.com/i/1525523
33 | Ensuring Efficiency through Isolation and Sensing Image Source: "aicandy / stock.adobe.com" So far, this series of articles on motor control has focused on the construction and function of electrical motors and ways to control and supply power to them. However, these are not the only features required to design a complete system that allows the motors to operate at peak efficiency while remaining safe. Also critical to the motor drive system are isolation and positional sensing. Isolation Isolation protects a circuit by creating a physical break in the current path (Figure 1), which is essential for most motors to operate. These motors use high voltages to function, usually delivered by MOSFETs arranged in an H-bridge configuration. The two MOSFETs connected to the positive rail also connect to the load, not the ground, while those MOSFET gates are connected to the control electronics through the gate driver. Without isolation, a direct path from the supply voltage to the ground through the MOSFET and control circuit could occur, resulting in a short circuit. Motors can generate a lot of electrical noise, and engineers must often specially choose system components to mitigate that noise or at least protect against it. Electric motor designs also feature isolation to protect sensitive components from noise and the disparity of voltages in different areas of the circuit. Voltages on the control side continue to decrease as smaller semiconductor processes are used to increase the efficiency of the circuit. This trend has led to many microcontrollers using voltages of 1V or lower. At the same time, the introduction of wide-bandgap semiconductors has led to the power side of the circuit evolving to use higher voltages and higher