Seismograph
Loudspeaker as vibration sensor
Published in issue 365, May 2007
Big earthquakes are rare events, but every now and then we are startled by small shocks that (luckily!) do not usually have any serious consequences. With the circuit described here and a PC you can very easily keep an eye on all earthquakes.
Resistors R1,R6 = 1MΩ R2,R5 = 100kΩ R3,R13 = 22kΩ R4 = 220kΩ R7,R12 = 4MΩ7 R8 = 15kΩ R9,R11 = 47kΩ R10 = 10kΩ Capacitors C1,C14 = 10µF 25V radial C2,C12,C13 = 220 µF 25V radial C3 = 2F2 C4 = 15nF C5 = 220nF C6 = 4F7 C7,C8 = 22pF C9,C16 = 1nF C10 = 470nF C11,C15 = 4F7 25V radial C17-C21 = 100nF Semiconductors D1,D2 = 1N4148 IC1 = LP2950CZ-5.0 IC2 = MAX7400CPA IC3 = ATtiny45 (programmed, order code 060307-41) IC4 = TL081ACN IC5 = TL082CN IC6 = LT1175CN8-5 Miscellaneous K1 = 9-way sub-D socket (female), PCB mount X1 = 4MHz quartz crystal PCB, ref. 060307-1 from www.thePCBShop.com
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Click below to download a PDF copy of this article from Elektor magazine.
Please note. In view of the complexity of international markets, Elektor cannot guarantee the availability of components for this project.
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