Electrical Power Systems Technology

450 Electrical Power Systems Technology be done by laboriously writing down each mnemonic and label, line by line, and then ente ...

Operational Power Control Systems 451 ing system. As a rule, each manufacturer has a unique set of component numbers for its sys ...

452 Electrical Power Systems Technology When the response of a particular input module is programmed, it may be identified as a ...

453 Chapter 17 Control Devices One of the most efficient methods of electrical power control that is circuit switching. When a s ...

454 Electrical Power Systems Technology IMPORTANT TERMS Chapter 17 describes control devices that are commonly used in elec- tri ...

Control Devices 455 lead determines when the device switches from its off to on state. An SCR will usually not go into conductio ...

456 Electrical Power Systems Technology ac applied to an SCR, it will automatically turn off during one alternation of the input ...

Control Devices 457 be exceeded for this to take place. Note that the IH level is just above the knee of the IAK curve after it ...

458 Electrical Power Systems Technology IG will cause an increase in the VBO needed to produce conduction. The gate current char ...

Control Devices 459 ing the anode positive and the cathode negative. When the circuit switch is turned on initially, the load is ...

460 Electrical Power Systems Technology Operation of the dc control circuit of Figure 17-6 is based on the con- duction of SCR 1 ...

Control Devices 461 that spark and arc when changes in load current occur. Control of this type, however, is only an on-off func ...

462 Electrical Power Systems Technology tion they would be the anode and cathode. For the other alternation they would respond a ...

Control Devices 463 are all connected to two pieces of crystal. Conduction will take place only through the crystal polarity tha ...

464 Electrical Power Systems Technology for half of each alternation permits 50% control. If conduction is for one- fourth of ea ...

Control Devices 465 Figure 17-9. Triac switching circuits: (a) static triac switch; (b) three-position static switch ...

466 Electrical Power Systems Technology state. The load does not receive any power for operation. All the supply voltage appears ...

Control Devices 467 Triac Variable Power Control The triac is widely used as a variable ac power control device. Con- trol of th ...

468 Electrical Power Systems Technology of the alternation. If conduction does not occur by this time, it will be off for the la ...

Control Devices 469 as fluorescent lamps, TV receivers, induction motors, and other transform- er-operated devices. SCR and tria ...