Signal Sources B Furman 31 JAN 2013 Mechatronics

Signal Sources B. Furman 31 JAN 2013

Mechatronics Concept Map Power Source User Interface ME 106 ME 120 Controller ME 106 (Hardware & Software) Power Interface Signal Conditioning INTEGRATION ME 106 ME 154 ME 157 ME 195 ME 106 ME 190 ME 187 ME 106 ME 120 Actuator Sensor System to Control ME 110 ME 182 ME 136 ME 189 ME 154 ME 195 ME 157 ME 120 ME 297 A BJ Furman 15 JAN 11

Signal Sources - 1 n Signal source concept ¨ Sensors as an information source n Their output voltage or current level encodes information about the quantity to be measured ¨ n Most often information is encoded as a voltage level ¨ n Ex. The voltage output from a Wheatstone bridge § The information: weight on the scale encoded as a voltage Current level also used ¨ ¨ Remember the dishwasher light sensor example? § Output voltage proportional to intensity of light 4 – 20 m. A commonly used in industrial controls Signals to power interface

Signal Sources - 2 n Sensor data sheets ¨ ADXL 203 n Precision ± 1. 7 g dual-axis accelerometer ¨ n Can use also to sense tilt § i. Phone display 1000 m. V/g sensitivity ¨ ¨ http: //www. analog. com/static/imported-files/data_sheets/ADXL 103_203. pdf Horizontal 17 mg/deg from horizontal 17 m. V/deg tilt Tilted mgsin(q) force component Dx q mg Sine function Slope=sensitivity

Signal Sources - 3 Vout n Ideal signal source ¨ ¨ n Ideal voltage source No output impedance 1 V/g Input quantity Practical signal source ¨ ¨ ¨ Relatively low-level output Finite output impedance Prone to noise Zero offset noise Non-linear 1 V/g Vout Ro Input quantity