| Electronics > Projects, Designs, and Technical Stuff |
| High temperature thin dielectric or insulating coatings for bare copper coils? |
| << < (6/7) > >> |
| magicsmoke:
--- Quote from: mzzj on February 10, 2020, 07:12:45 pm ---https://acc-silicones.com/products/encapsulants/QSil550 Thermally conductive silicone with 275cel max temp --- End quote --- Thanks for the link! |
| David Hess:
I would not even try it without using a vacuum during application. My own experience is that a thick application will crack the insulating material or worse unless the temperature coefficient and elasticity are suitable. Potting compounds tend to be very elastic which will not be suitable in this case. Sometimes a more compliant base coat is used before a hard potting compound. |
| magicsmoke:
I actually found something that might work for the turn to turn insulation (CTD-201 Polyimide Coating, https://www.ctd-materials.com/wordpress/wp-content/uploads/2014/05/CTD201-Polyimide-Coating-December-2013.pdf). It looks like it is sprayable and suitable for complex shapes. Not sure if it can be made to wick inside which as David mentioned probably requires a vacuum system. |
| magicsmoke:
--- Quote from: David Hess on February 13, 2020, 12:39:00 am ---I would not even try it without using a vacuum during application. --- End quote --- Have you tried anything like this with a jury rigged/non-professional vacuum or VPI system? |
| trobbins:
--- Quote from: magicsmoke on February 10, 2020, 06:44:12 am ---Yes, there will be increased AC resistance just because of the high frequency AC excitation (skin and proximity effects). The PWM harmonics will also add additional losses. I am going to try to build in some features to the coil to mitigate these losses. --- End quote --- Have you estimated Rac/Rdc for the operating waveform? I can appreciate you may be able to modify proximity losses, but not skin effect. If effective Rac/Rdc is more than say a few % increase, or you can't confidently model and do some form of prototype test confirmation of AC losses, then I can't see any merit in maxing out the single conductor copper area to aspire to a max slot fill %, to the detriment of a myriad of foreseen and unforeseen risks. Perhaps you've looked at other practical conductor structures and assessed that a single conductor is the best outcome for your operating current waveform. |
| Navigation |
| Message Index |
| Next page |
| Previous page |