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Friday, September 24, 2010

How to create a magnetic lock: Phase III: E core's Bobbin

41mm E core
Remember the E core I shown you on previous post?

According to the Uncle that teach me to do winding, we can't do the winding in the core. We must first make a bobbin, do the winding in the bobbin, then only take out the winding and put it into the core.
Note that, bobbin are usually made by plastics or woods. The model that I show here is not the common way of making a bobbin. This is a self impress creative babe's idea to do a one time bobbin. If it happens to be very useful, don't forget to let me know.

bobbin measurement for 41mm E core
First design the measurement that we wanted. Some place must the slightly longer and some place must be slightly smaller so that the winding can still fit in the core after the winding is coated with insulated.

I use Model board to do it. Sort of recycle item.
measure and cut

Then, use white glue to attach them together.
glue it with white glue

I compress the glued model board so as to minimize the space/length take up by glue when it stack up.
compreses the model board

This is how to bobbin looks like. I did 4 sets, but I only manage to finish 1 winding. Will take about that later on the next post.
1 time bobbin


  1. nice article. magnetic locks are the high security locks provide high security to home. generally magnetic locks are used for front door.