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Variable Resistance Piano | Variable Resistance Piano | ||
The first assignment was to build a fancy variable electronic resistor. I built a table-sized piano made of a wet cardboard. The resistance increases with the distance between the cable connection. The internal structure of the cardboard affect on the current | The first assignment was to build a fancy variable electronic resistor. I built a table-sized piano made of a wet cardboard. The resistance increases with the distance between the cable connection. The internal structure of the cardboard affect on the current. | ||
[[Image:Wetcardpiano.jpg]] | [[Image:Wetcardpiano.jpg]] | ||
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The current flows through a basic 555 timer circuit - creating square wave oscillations which can be played on a speaker. By changing the distance between the connection on the cardboard you can change the resistance and the pitch of the tone. | The current flows through a basic 555 timer circuit - creating square wave oscillations which can be played on a speaker. By changing the distance between the connection on the cardboard you can change the resistance and the pitch of the tone. | ||
'''Assignment II: | |||
''' | |||
The Boiling Water Indicator | |||
The second assignment was to build a fancy electronic switch. I built a construction of a basic 555 timer circuit (creating a square wave oscillation connected to a speaker) which power on/off is triggered by a connection of two contacts. I put the contacts into a water filled glass tube which was set over a flame. Immediately after the water is boiling the expanded water volume let current pass to the circuit. | |||