Got an old Brown & Sharpe magnetic base for indicators, well made and heavy, but the magnet is so weak as to be useless. Disassembled the core, made sure the on/off knob was timed correctly to the poles of the core. Then I established the existing polarity with a compass and stroked the core one direction with a strong speaker magnet. Very little improvement. So, I guess I need to "flash" the core with dc and a hand wound coil?
A difficulty arises when it is assumed that the cylindrical core 1 1/4" x 2 1/2" is polarized on the short axis. In other words, viewing the core cylinder from either end, the magnetic poles reside in the hemisphere....rather than the long axis as would be found on a common bar magnet. Thus, my question: how to wind my coil, it's shape and it's direction? And yes, I was asleep during 5th grade science class. Thanks, Paul
A difficulty arises when it is assumed that the cylindrical core 1 1/4" x 2 1/2" is polarized on the short axis. In other words, viewing the core cylinder from either end, the magnetic poles reside in the hemisphere....rather than the long axis as would be found on a common bar magnet. Thus, my question: how to wind my coil, it's shape and it's direction? And yes, I was asleep during 5th grade science class. Thanks, Paul