The two 555 timers are operated in two modes. Frequency Counter Circuit: This project shows a frequency measuring circuit.This circuit is designed using 555 timer IC. LC Meter Circuit using 555 Timer: The LC meter circuit shown here will measure the value of a reactive element like capacitor or an inductor.Audio signals are frequency modulated and video signals are PAL modulated. This circuit amplifies and transmits the signals. TV Transmitter Circuit:The TV Transmitter circuit designed here can transmit audio and video signals.The circuit shown here is build using a 555 timer circuit. Because of its ear piercing and irritating sound it can get immediate attention. Screaming Siren Circuit: Screaming Siren can be used as an Alert signal.It compares the input voltage with the two reference voltages and produces an equivalent voltage at the output. Schmitt trigger is a regenerative comparator. 555 Timer as Schmitt Trigger: Here the 555 timer is used as a Schmitt trigger.How 555 Timer IC Testing Circuit Works?: This article explains the working of a 555 timer IC tester.This article explains the working of this mode. Monostable Multi vibrator using 555 Timer: In monostable mode 555 timer changes its state when only external trigger is applied.This article explains the working of timer in this mode. Astable Multivibrator Using 555 Timer: Astable mode is also called free running oscillator.IN this state 555 timer can trigger between two states without applying between any external triggering.Different modes ,pin configuration, applications of the timer are also explained. Understanding 555 Timer: Here is the article explaining about the 555 timer.List of Simple 555 Timer Circuits and Projects Here is the list of 40 555 timer circuits that can help you in understanding 555 timer functions.First five circuits explains about 555 timer and its different modes. It is a affordable, stable and user friendly IC in application such as monostable and bi stable. Its name is derived from three 5K ohm resistors ,connected in series used in it.The timer IC can produce required waveform accurately.ĥ55 timer was first introduced by signetics corporation in 1971 as SE555/NE555. 555 timer is an industrial standard IC existing from early days of IC.

555 circuits projects