667Chapter 19
Power Supplies
by Glen Ballou
19.1 Power-Supply Terminology............................................................... 669
19.2 Power Supplies......................................................................... 672
19.2.1 Simple dc Power Supplies.............................................................. 672
19.2.2 One-Half Wave Supplies............................................................... 672
19.2.3 Full-Wave Supplies................................................................... 672
19.2.4 Three-Phase Power Supplies............................................................ 674
19.3 Filters................................................................................. 674
19.3.1 Capacitor Filters..................................................................... 674
19.3.2 Inductive Filters...................................................................... 675
19.3.3 Combination Filters................................................................... 676
19.3.3.1 Inductance-Capacitance Filters (LC).................................................. 676
19.3.3.2 Resistance-Capacitance Filters...................................................... 676
19.3.3.3 S Filters........................................................................ 676
19.3.4 Resistance Voltage Dividers............................................................ 677
19.4 Regulated Power Supplies................................................................ 677
19.4.1 Simple Regulated Supplies............................................................. 679
19.4.2 Complex Power Supplies.............................................................. 680
19.4.3 Switching Regulators................................................................ 682
19.4.4 Phase-Controlled Regulated Power Supplies............................................... 683
19.5 Single IC, Power Factor Corrected, Off-Line Supply............................................ 684
19.6 Synchronous Rectification Low-Voltage Power Supplies........................................ 684
19.6.1 Diode versus Synchronous Rectifiers..................................................... 685
19.6.2 Secondary-Side Synchronous Rectifiers................................................... 688
19.7 Converters............................................................................. 690
19.8 Inverters............................................................................... 690
19.9 Ultra Capacitor (UPS).................................................................... 690
19.9.1 Ultra Capacitor Characteristics.......................................................... 691
19.10 Batteries.............................................................................. 692
19.10.1 Temperature Effects................................................................. 692
19.10.2 Cycles versus Battery Life............................................................. 692
19.10.3 Battery Voltage..................................................................... 692
19.10.4 State of Charge..................................................................... 692
19.10.5 False Capacity...................................................................... 692
19.10.6 Ampere-Hour Capacity............................................................... 693
19.10.7 Battery Charging.................................................................... 693
19.10.7.1 Equalizing..................................................................... 694
19.10.7.2 Charging Voltage versus Temperature............................................... 694
19.10.7.3 State of Charge................................................................. 694
19.10.7.4 Internal Resistance............................................................... 694