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Signal Sources. B. Furman 31JAN2013. Power Source. Controller (Hardware & Software). Power Interface. User Interface. Actuator. Signal Conditioning. Sensor. System to Control. ME 110 ME 136 ME 154 ME 157. ME 182 ME 189 ME 195. Mechatronics Concept Map. ME 106 ME 120. ME 106
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Signal Sources B. Furman 31JAN2013
PowerSource Controller(Hardware & Software) PowerInterface UserInterface Actuator SignalConditioning Sensor System toControl ME 110 ME 136 ME 154 ME 157 ME 182 ME 189 ME 195 Mechatronics Concept Map ME 106 ME 120 ME 106 ME 190 ME 187 ME 106 INTEGRATION ME 106 ME 120 ME 106 ME 154 ME 157 ME 195 ME 120 ME 297A BJ Furman 15JAN11
Signal Sources - 1 • Signal source concept • Sensors as an information source • Their output voltage or current level encodes information about the quantity to be measured • Remember the dishwasher light sensor example? • Output voltage proportional to intensity of light • Most often information is encoded as a voltage level • Ex. The voltage output from a Wheatstone bridge • The information: weight on the scale encoded as a voltage • Current level also used • 4 – 20 mA commonly used in industrial controls • Signals to power interface
Dx mgsin(q)force component q mg Signal Sources - 2 • Sensor data sheets • ADXL203 • Precision ±1.7 g dual-axis accelerometer • Can use also to sense tilt • iPhone display • 1000 mV/g sensitivity • 17mg/deg from horizontal • 17 mV/deg tilt http://www.analog.com/static/imported-files/data_sheets/ADXL103_203.pdf Horizontal Tilted Slope=sensitivity Sinefunction
Vout 1V/g Input quantity Vout Ro Input quantity noise 1V/g Signal Sources - 3 • Ideal signal source • Ideal voltage source • No output impedance • Practical signal source • Relatively low-level output • Finite output impedance • Prone to noise • Zero offset • Non-linear