The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation, and oscillator applications. The 555 can be used to provide time delays, as an oscillator, and as a flip-flop element. Derivatives provide up to four timing circuits in one package.
planar passivated sensitive gate 4-quadrant TRIAC for general purpose bidirectional switching and phase control applications. This series TRIAC is intended to be interfaced directly to microcontrollers, logic integrated circuits and other low power gate trigger circuits.
The very popular 595 shift register chip of the 74 series is used a lot by hobbyis because of its wide availability, good speed and simplicity. Just plug it on an arduino like shown in the tutorials and youi have 8 more outputs, put two and you have 16 more outputs ! (up to a lot of them actually, with only three pins !)
The 556 Dual Monolithic timing circuit is an highly stable controllers capable of producing accurate time delays or
oscillation. The 556 is a dual 555. Timing is provided by an external resistor and capacitor for each timing function. The two timers operate independently of each other, sharing only VCC
and ground. The circuits may be triggered and reset...
CD4077BE is a quad CMOS Exclusive-NOR Gate for use with logical comparators, adders/subtractors, parity generators and checkers. The CD4077B provide the system designer with a means for direct implementation of the Exclusive-OR and Exclusive-NOR functions, respectively.