555 Timer - EIM Lab-OnThe-Go Manual

LOTG Lab-On-The-Go Manual
Different types of packages are available for BJTs to suit specific
applications. Smaller packages are typically used for signal processing
applications and have a lower current handling capacity, while larger
packages with metal plates are designed for higher current loads and may
require a heat sink to dissipate the heat generated.
Another important characteristic of BJTs is that they are capable to amplify
small signals to a larger amplitude. Nevertheless, BJT amplifiers are
relatively advanced topic that involves quite a bit of circuit fundamentals,
they will be discussed in the book Experimental Discovery of Basic
Microelectronics.

555 Timer

The 555 timer is an integrated circuit first introduced in 1970s by Signetics
Corp., which was designed for timer and oscillator applications. The 555
timer consists of two comparators, a flip-flop, and a discharge transistor,
all of which are controlled by an external RC circuit. The timing interval
is determined by the values of the resistors and capacitor in this external
circuit.
22