Circuit to detect conductive coating.

  • #1
Basically to detect whether a lens has EMI coating or not.
 

Answers and Replies

  • #2
Doug Huffman
Gold Member
804
111
EMI is Electro Magnetic Interference?
 
  • #3
Baluncore
Science Advisor
8,708
3,366
Build a level controlled oscillator with a resonant capacitor and inductor. Include a supply current meter. As the coil approaches the conductive EMI layer, the eddy currents induced in the conductive coating will draw power from the resonant circuit and be indicated by an increase in oscillator current.

EM waves will wrap around the outside of the conductive surface, so EMI coatings will only work if the lens is mounted in a metal wall or the end of a metal tube. The advantage of the conductive layer is probably in the reduction of static electricity attracting dust. Static can be eliminated without an EMI coating by using a drop of ethylene glycol, (antifreeze), when you wipe your lenses.
 
Last edited:

Related Threads on Circuit to detect conductive coating.

Replies
9
Views
2K
  • Last Post
Replies
2
Views
3K
Replies
25
Views
1K
  • Last Post
Replies
9
Views
5K
  • Last Post
Replies
2
Views
5K
  • Last Post
Replies
5
Views
7K
  • Last Post
3
Replies
54
Views
9K
Replies
16
Views
3K
Replies
16
Views
3K
Replies
2
Views
677
Top