Active components, or Active Parts rely on a source of energy (usually from the DC circuit, which we have chosen to ignore) and usually can inject power into a circuit, though this is not part of the definition. Active components include
- Transistors (FET, composite transistors, other transistors, Thyristors)
- Diodes (Diode, Schottky diode, Zener diode, TVS, Laser diode, LED, Photodiode, DIAC, Constant-current diode, Peltier cooler, Tunnel diode)
- ICs (IC, Digital electronics, Analog circuit)
- Optoelectronic devices (Opto-electronics LED display)
- Display technologies (Filament lamp, Vacuum fluorescent display, Cathode ray tube, LCD, Neon, LED, Split-flap display, Plasma display, OLED, Micro-LED, 7 segment display, Nixie tube, Dekatron, Magic eye tube indicator, Penetron)
- Vacuum tubes (valves) (Diode or rectifier tube, Amplification, Oscillation, Optical detector or emitters)
- Discharge devices (Gas discharge tube, Ignitron, Thyratron, Mercury arc rectifier, Voltage regulator tube, Nixie tube)
- Power sources (Battery, Fuel cell, Power supply, Photovoltaic device, Thermoelectric generator, Piezoelectric generator, Van de Graaff generator)
Also see Passive Components. and Electromechanical Components.