The simplest electric motor

It's dif­fi­cult to pic­ture our mod­ern world with­out elec­tric en­er­gy. But do you know how to con­vert elec­tric­i­ty into mo­tion? It’s ac­tu­al­ly quite sim­ple! Let's take a look at how to make the sim­plest elec­tric mo­tor.

Safe­ty pre­cau­tions

• Do not leave the cir­cuit closed for more than 1 minute! This may cause the bat­tery to burn out!
• Per­form this ex­per­i­ment only un­der adult su­per­vi­sion.

Equip­ment

• AA bat­tery;
• ad­he­sive tape;
• clay;
• two safe­ty pins;
• neodymi­um mag­net;
• cop­per wire;
• sand­pa­per.

Step-by-step in­struc­tions

First, make an in­duc­tion coil out of cop­per wire. Wind the wire tight­ly around an AA bat­tery. Se­cure the coil by wrap­ping the ends of the wire through and around it sev­er­al times. Use sand­pa­per to re­move the up­per half of the wire iso­la­tion on each end of the coil. Be sure to ex­pose the same side of the wire on both ends. Use ad­he­sive tape to fas­ten a safe­ty pin on each pole of the bat­tery. At­tach the bat­tery to a flat sur­face us­ing clay. Place a neodymi­um mag­net on top of the bat­tery. Thread the coil con­tacts through the loops in the safe­ty pins. The coil starts spin­ning! The en­gine is run­ning!

Process de­scrip­tion

When the ex­posed sec­tions of the coil touch the safe­ty pins, the coil, bat­tery, and pins to­geth­er form a closed cir­cuit that cur­rent can flow through. As cur­rent flows through the coil, it cre­ates a mag­net­ic field both in­side and out­side, turn­ing the coil into an elec­tro­mag­net. The in­ter­ac­tion with the neodymi­um mag­net's field caus­es the coil to ro­tate as it tries to reach a po­si­tion of equi­lib­ri­um. But as it turns, the cir­cuit opens, and in­duc­tion cur­rent runs through the coil in the op­po­site di­rec­tion to the ini­tial cur­rent. In oth­er words, the po­lar­i­ty of the elec­tro­mag­net, and its po­si­tion of equi­lib­ri­um change. The coil turns once more, and the con­tacts close again. The cur­rent swtich­es di­rec­tions again, back to the way it was. Due to the cur­rent's cycli­cal re­ver­sal in di­rec­tion, the coil makes a full turn each time. This re­sults in con­tin­u­ous ro­ta­tion. This is an ex­am­ple of the sim­plest elec­tric mo­tor, which some­what re­veals the ba­sics of how elec­tri­cal en­er­gy con­verts to me­chan­i­cal en­er­gy.