If you're a person who has many knives, and many edges to sharpen at a fairly consistent pace, electric knife sharpening is for you. This saves a lot of time and effort. But be careful. Unfortunately, using this device without proper training and just a little experience can go a long way.
electric knife sharpener is known to generate a lot of heat while sharpening. Friction from the metal edge against the blade over time will cause this. You've got to know just how hot you'll allow the metal edge to get. If your knife changes color while you wait for it to become a mark, you screwed up.
If you see a spark, forget it. Your knife tip overheats and loses control. Yes, you have an angry knife in your hand!. To lose temper on a blade means that you have weakened it. Made it brittle, even pliable. Just imagine using it now. That is a knife that you don't want. Even knowing that electric knife sharpeners have improved a great deal over the last decade. Some of them are astonishing in what they claim they're able to do.
Many of the latest electric knife sharpeners have improved to having several sharpening stages all in one. The first stage is meant to get the edge to sharpness. You could stop right there if you wanted. The second stage is usually a finer sharpening with smaller abrasive particles than is found in the first stage. It is meant to get the edge to razor-sharpness. The third stage is meant for stropping. How about that? An electric knife stopper to get your edge silky smooth. Absolutely extraordinary.