How to Make Your Own Tone Generator

two speakers sitting side by side
What You'll Need
Soldering gun
CD drive motor
Mini motor
4-inch speaker
Black and white ribbon cable
8.2v power supply
Wire stripper

A tone generator is known by several names including function generator, signal generator, frequency generator, digital pattern generator and pitch generator. A tone generator is built to create non-repeating as well as repeating electronic sounds. These tones can either be analog or digital in nature. A tone generator is often used to test, repair, troubleshoot, and design other electroacoustic and electronic devices. A tone generator can also be used as a way to generate musical tones made popular by DJs all over the world. Building a tone generator is not that difficult and can be done with simple electronics you may already own and this article will show you how.

Step 1 - Wire the Motors and Speaker

soldering wires together

Each of the motors you have should already have wires attached to them. If they do not, then add some by soldering them in place. Otherwise you can use the wire strippers to remove the casing from each of the wires. Take apart the 4-inch speaker and remove the wires coming out of it. When you are finished all of these components will be connected to each other.

Unravel the ribbon cable and strip the ends of the dual black and white wire as well as the ends of the large white cable. Solder the white cable from the ribbon cable to the positive of the speaker and the positive wire from the CD drive motor to the negative of the speaker. The next thing to do is to solder the negative wire from the CD drive motor to the positive of the mini motor. The final bit of wiring is to solder the negative of the mini motor to the negative wire of the black and white dual wire. Once you do these connections you have the main wiring of the tone generator complete.

Step 2 - Power Supply

The power supply can be salvaged from many current video game consoles. These are perfect because the end that goes inside the game console is round. Form the exposed wire from the white cable into a loop and slide it onto the end of the round power supply jack. Make sure it is tightly wound and fits snug on the cable.

Step 3 - Using the Tone Generator

This is a simple tone generator and to use it is just as simple as it was building it. Plug the power supply into the wall. You'll notice that both motors will begin to move and sound will be generated through the speaker. You are essentially creating an AC current instead of a DC current. You can change the tone generated by applying pressure to either of the motors. As you manipulate the motors you are actually causing a short to occur. Once this happens the current is directed through the other wires which in turn creates a tone that can be heard through the speaker. It may take time and experimentation to understand its applications.