I have attached a file with a diagram of the circuit I need help with. Any feedback would be appreciated.

 

Try touching the ends of your coild to the + and - sides of a AA battery, if your pendulum doesn't move, your coil isn't big enough, or you have standard stainless steel (Austentic Crystal)

Heat treated Stainless Steel or Stainless Steel with a very high chromium content will form the ferritic crystal structure, which does respond to magnetism.

Use a non-stainless steel pendulum and you should have problems. If a fridge magnet will stick to it, the material should work.

 

As to the need to control the strength of the magnetic field. raising and lowering the coil would be the simpliest way to do this. A support on threaded rod could be rotated with your finger to raise and lower the coil. (you would want to use stainless steel or brass threaded rod here so it would not affect the field.)

 

Thank you Kermit2 and thatoneguy for your help. I am looking for advice about how changing component values or number of components will effect the strength of the field
produced by the coil. Will increasing capacitance make the field stronger? Should I add capacitors or change the values? I plan on using batteries to power the circuit. I would also like to control the output of the circuit to be able to adjust the strength of the electromagnet. The pendulum is SS tube with rare earth magnet in the end of the tube.

 

The major determining factor of field strength will be what was once called 'amp turns'. Maybe it is still referred to in this way today, but I'm sure some other term has come into use since I was in school.

It basically means, how many 'turns of wire' and how many amps are flowing through them. The more turns of wire and the more amps the stronger the field.

when wound as a solenoid shape(hollow cylinder); one turn of wire with one amp flowing should theoretically produce the same strength field inside the coil as one milliamp flowing in 1000 turns of wire. Hopefully you get the basic gist of this simplified explanation. 1000 turns x .001 amp = 1 amp-turn and 1 turn x 1 amp = 1 amp-turn