BC239 is a low noise NPN epitaxial silicon transistor. Available in TO-92 package with collector, base, and emitter sections
Arduino's IO pins can handle up to 40mA per pin, totaling 200mA. Arduino's digital output is limited to 0-5V. Transistors are needed for high-current loads like motors and LEDs
Darlington pair consists of two bipolar transistors with joined base-emitter junctions. Invented by Sidney Darlington in 1953. Acts like a single transistor with one base, collector, and emitter
Semiconductors are materials between conductors and insulators in electrical conductivity. Impurities (doping) can modify semiconductor properties significantly. Two differently doped regions form semiconductor junctions. Silicon and germanium are most common semiconductors
2W output amplifier for portable radios in Class B push-pull operation. Complementary to SS8550 with 1.5A collector current. Pb-free, halogen-free/BFR-free and RoHS compliant
Pb-free packaging available for BC546B, BC547A, B, C, BC548B, C series. Maximum collector-emitter voltage: 65V for BC546, 45V for BC547, 30V for BC548. Maximum collector-base voltage: 80V for BC546, 50V for BC547, 30V for BC548. Operating temperature range: -55°C to +150°C