Why can't weak core-less electromagnets be used in conjunction with strong permanent magnets to perpetually harvest energy?
Magnets will attract ferrous materials but some materials like copper or silicon are not effectively magnetic unless a current is passed through them, if that is the case then why can't we arrange a core-less electromagnet made of copper in conjunction with strong permanent magnets to create a system in which one could easily harvest energy? Once a weak current is passed through the core-less electromagnet it could become attracted to a strong permanent magnet due to a relatively weak magnetic field surrounding it, energy would be harvested by means of compression between the electromagnet and the strong permanent magnet, the electromagnet would be turned off and another permanent magnet would drag the electromagnet away by attracting an attached permeable material, then the electromagnet could be switched back on and the cycle would reset.
The simple device below portrays my question in better light
A= Weaker permanent magnet
D= Ferrous material
C= Core-less copper electromagnet (Copper circuit)
B= Very strong permanent magnet
(A and D are both out of the effective magnetic range of C and B)
D is instantly attracted to A
A very weak current in passed through C creating a weak but existent magnetic field, it's instantly attracted to B the much stronger permanent magnet, dragging D from A, since C's current/magnetic field can be extremely weak as long as B's magnetic field is extremely strong, couldn't one perpetually harvest energy from this arrangement?
I had another picture but I don't have enough reputation to post it
I'm not overly familiar with the formal physical laws that will most likely prevent a system like this from working so a practical answer will be highly appreciated, I hope these images will help explain my question.