Experimentation of capacitor temperature characteristic
In this project, you are going to experiment how a capacitor changes in capacitance with temperature. You need no measuring instrument to know the result of your experiment. The sound from the speaker tells you the result.
When you finish wiring, turn power ON. You should be hearing a sound of approx. 500 Hz.
Heat C1, for example using a hair dryer. As the temperature of C1 rises, the capacitance of C1 changes, so that the oscillating frequency increases, as indicated by gradual increases in frequency of the speaker sound.
Now, stop the heating. The oscillating tone should lower to the original frequency of approx. 500 Hz. Could you realize that the capacitor changes in capacitance with temperature?
C1 is part of an oscillating circuit, which is oscillating at approx. 500 Hz at normal temperature. The oscillation output is hooked up to the speaker via an OUTPUT Transformer, so a sound of approx. 500 Hz emits from the speaker.