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Activities/Turtle Art/Using Turtle Art Sensors (view source)
Revision as of 03:10, 8 November 2010
, 03:10, 8 November 2010→Carbon Microphone
[[File:Carbon microphone materials.jpg]]
[[File:Carbon microphone materials.jpg]]
Crush the charcoal to a fine powder. Make a hole in the centre of the lid. Strip a small amount of insulation from the wire, pass the wire through the hole. Then place a piece of foil against the wire. Fill the lid with crushed charcoal. Place foil over the charcoal and secure with a rubber band.
Crush the charcoal to a fine powder. Make a hole in the centre of the lid. Strip a small amount of insulation from the wire, pass the wire through the hole. Then place a piece of foil against the wire. Fill the lid with crushed charcoal. Place foil over the charcoal and secure with a rubber band. Connect a wire to this foil. Try to get the foil under tension.
[[File:Complete microphone.jpg]]
Experiment with the fineness of the crushed charcoal and the tension in the foil. The more squashed the charcoal is, the lower the resistance. Aim for a resistance of around 3k ohms and definitely 700 ohms < resistance < 14k ohms.
Graph the resistance, pressing on the foil changes the resistance. You have built a pressure sensor. It can also sense air pressure. Change to Sound sensing. On my first try I was able to sense clapping.
==Links==
==Links==