Page 10 - Basics of Electrical, Electronic and Communication

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12.16.3 Crystal oscillators . . . . . . . . . . . . . . . 232

13 Digital Systems 235
13.1 Digital systems . . . . . . . . . . . . . . . . . . . . . 235
13.1.1 Digital logic states . . . . . . . . . . . . . . . 236
13.1.2 Logic gates . . . . . . . . . . . . . . . . . . . 238
13.1.3 Compound gates . . . . . . . . . . . . . . . . 240
13.1.4 Universal gates . . . . . . . . . . . . . . . . . 244
13.1.5 Boolean algebra . . . . . . . . . . . . . . . . 245
13.2 De Morgan’s theorem . . . . . . . . . . . . . . . . . . 247
13.3 Forms of Boolean expressions . . . . . . . . . . . . . 248
13.3.1 Sum of Products (SOP) . . . . . . . . . . . . . 248
13.3.2 Product of Sums (POS) . . . . . . . . . . . . . 248
13.4 Simplification of Boolean expressions . . . . . . . . . 249
13.5 Generating Boolean expression from truth table . . . . 253
13.6 Implementing circuits from Boolean expressions . . . 254
13.7 Generating Boolean expression from logic circuit . . . 257
13.8 Implementation of logic circuits using universal gates . 259
13.8.1 Implementation using NAND gates only . . . . 260
13.8.2 Implementation using NOR gates only . . . . . 262
13.9 IC logic families . . . . . . . . . . . . . . . . . . . . 264
13.9.1 TTL logic family . . . . . . . . . . . . . . . . 264
13.9.2 CMOS logic family . . . . . . . . . . . . . . . 268
13.9.3 Comparison of TTL and CMOS logic families 270
13.10Programmable logic device . . . . . . . . . . . . . . . 270
13.11Advantages of PLDs . . . . . . . . . . . . . . . . . . 273

14 Measurements and data acquisition systems 275
14.1 Electronic measurements . . . . . . . . . . . . . . . . 275
14.2 Cathode ray oscilloscope . . . . . . . . . . . . . . . . 275
14.2.1 Cathode ray tube . . . . . . . . . . . . . . . . 277
14.2.2 Waveform display on a CRO . . . . . . . . . . 278
14.3 Sensors and actuators . . . . . . . . . . . . . . . . . . 280
14.3.1 Sensors . . . . . . . . . . . . . . . . . . . . . 280
14.3.1.1 Temperature sensors . . . . . . . . . 281
14.3.1.2 Light sensors . . . . . . . . . . . . . 283
14.3.1.3 Force sensors . . . . . . . . . . . . 284

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