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== Assignment 2: switches== | == Assignment 2: switches== | ||
'''switch, relay, motor''' 2 contact/ momentary switches,relay,555 timer, trash | |||
<videoflash type="vimeo">136196422|400|265</videoflash> | |||
By changing conductive material(water, metal..), you change the resistance and the pitch of the tone. | |||
schematic for 555 timer in astable mode with speaker and different conductive materials | |||
[[File:555_astable_2_small.jpg]] | |||