NE555 Example Project: Light detector
NE555 Operation The NE555 comprises 23 transistors, two diodes 16 and resistors which form four elements: two operational amplifiers Compare type; an inverter logic gate; SET and RESET latch. The NE555 can operate in three modes: monostable, astable or bistable. I will detail precisely two in this article, the third being extremely simple. Astable operation For me, this is the simplest operation. This configuration allows to use the 555 as oscillator which will generate a square wave signal at its output. The astable word means that the timer has no stable state.