From the Technology Enhancement Programme (TEP), these circuits allow students to build a range of devices. Each circuit has a full circuit diagram, component list and explanation of how the circuit works. In this section, the circuits cover a range of sound and audio devices.
This circuit produces a sound similar to the sound produced by an American police car.
When sound impinges, e.g. snapping of fingers on the speaker, an LED will light and remain in that condition. i.e. the circuit is latched.
An organ that can produce eight notes to play a simple tune.
Used primarily in music boxes, toys and musical cards, when activated this circuit will play a popular ditty.
Jewellery box sound switch
When the lid of a jewellery box is raised, a popular ditty will be played.
Morse code trainer
This circuit can be used as a Morse code trainer. When a key or switch is depressed, the speaker emits a note at the same frequency as the dots and dashes transmitted in Morse code operation.
This circuit produces a sharp clicking sound at regular intervals. This is useful to keep time in music.
This circuit provides a means for two people (say in different rooms) to communicate with each other.