Power switching devices are employed for controlling inductive, resistive or capacitive loads. Inductive loads include electrical machines, transformers, solenoids, and relays. High-current in-rush occurs with loads such as incandescent lamps, pulse-forming networks, snubbers, and motors. Incandescent lamps are essentially resistive, but the cold resistive in-rush current during turn-on is 12 to 18 times the steady-state current. This turn-on surge presents special switch-on problems. Capacitive loads, such as fluorescent lighting, also present high-current in-rush at turn-on. Electromechanical loads, such as shakers, present loads that vary between capacitive and inductive over their operating frequency range.
پسورد : 4power
سرچشمه: مهندسی تکنولوزی برق