Despite this, Magshape Grey has an electrical resistivity which limits eddy currents and consequently strongly reduces power losses. However, it is important to insulate the turns of the coil in order not to cause a short circuit which is the primary cause of material deterioration.
How to insulate?
There are several ways to insulate:
- Protecting the coils or MAGSHAPE GREY with a thin layer of insulating paint;
- Inserting an insulating material between coil and concentrator;
- Separating the flux concentrator into two or more separate parts.
In applications where concentrator cooling is not required, the following insulation techniques can be used: it is suggested to paint the coil using an insulating paint which is generally used to coat electrical machines.
Alternatively, a silicone spray can be used as it is often employed to insulate the high voltage windings of electrical machines or in order to protect electronic circuit boards.
This type of paint resists most lubricants and oils, it has good dielectric characteristics (up to 90 KV / mm) as well as great heat resistance (from – 70 to + 300°C).
As for the second point, relating to the insertion of a material between coil and concentrator, it is recommended to use an epoxidic compound or a silicone compound with good thermal conductivity and very high electric resistivity.
Alternatively, thermal conductive pads: these compounds are normally used in power electronic industries to obtain a good thermal contact between power transistors and heatsinks.
As for the last point, a Teflon sheet or other high temperature electrical insulating materials (for example Mica) can be used.