Eliminating voltage notching requires that the source of the notching (commutation) be isolated or buffered from other sensitive equipment using the same distribution system. (Rockwell Automation)

The types of equipment that frequently utilize SCR control schemes and thus experience notching include DC motor speed controls and induction heating equipment. (MTE)

The notching is a normal characteristic of a phase-controlled rectifier but this paper illustrates problems that can occur on systems with low short circuit levels where the voltage notching can excite the natural frequency of the distribution system and cause significant distortion in the supply voltage. (CAT.INIST)