Organize and Share your Electronics the way you want. Sign-Up for a free account now. It takes only 30 seconds!

# A motor with two coils

In this section we will construct a motor without any permanent magnets. In place of the magnet, we will use another coil of wire. This coil is called the field coil, and the coil that moves is called the armature coil.
The simplest way to do this would be to replace the permanent magnet with a coil of wire connected to a second battery. But we can save the second battery, and waste less electricity, by arranging the coils as shown in the diagram.

The diagram shows how the electrons flow in the coil. They start where the negative terminal of the battery is connected (marked here with a minus sign). They then flow around and around inside the field coil until they come to the first support loop on the right. From there they flow into the armature coil, going round and round until they come out the other end, and flow into the second support loop on the left. From there they travel back to the positive terminal of the battery.

You can see that when the electricity flows in one coil, it also flows in the other. When the armature turns over, and the insulation cuts off the flow of electricity to the armature, it also cuts off the flow of electricity to the field coil at the same time.

Because both coils turn on and off together, we never have a condition where one coil is on when the other is off. That would be a waste of electricity.

The photograph above shows the completed motor. I used three different types of wire to more easily show how it goes together.

The heavy green wire is the field coil. It is wound with about 50 turns of wire around a D battery, then removed. The wire ends are wrapped around the coil to keep it tight, just as we did with the armatures of all the other motors.

One end of the field coil wire is stripped of its insulation, and formed into a loop for the first support. The other end goes to the battery.

A brown wire forms the second support. One end is stripped and formed into a loop, and the other end winds around the coil a few times to make a sturdy support, then it goes to the other terminal of the battery.

The armature is made of thin green wire, and is formed in the same way we did for the other motors. A couple of plastic beads keep the armature centered (they are optional).

This motor works fine running from a D cell, and runs faster from a 9 volt battery.

Visit Here for more.

App note: Infrared remote control implementation with MSP430FR4xx
Gesture Controlled Smart Home
Design for a Wideband, Differential Transimpedance DAC Output
Wrist thrusters let you fly through the water effortlessly
Bertan/Spellman 225-20R HV power supply teardown
Adjusting clock with alarm, hygrometer & thermometer on 1.8″ ST7735 display
Adding an “extra sense” with rangefinders
This wireless game controller looks like a rug
How to run your ESP8266 for years on a battery
Calibration of a 3-Phase Energy Meter Board on the ADE7754
Making beats on a tiny Arduino DJ controller
Qinsi-QS5100 Sn63Pb37 solder profile
Water Detection System
Professional Hi-Fi 15W Tube Amplifier circuit
This Arduino machine will judge how sick your ollies are
Turn an old payphone into a boombox for ’90s hits
Big F’n 3D printer build
Temperature alarm for boiling milk
QuadBot is a 3D-printable walking robot for everyone

Top