Portable rain water detecting alarm using ic 555 timer

The 555 Timer IC

The 555 timer IC was first introduced around 1971 by the Signetics Corporation as the SE555/NE555 and was called "The IC Time Machine" and was also the very first and only commercial timer IC available. It provided circuit designers with a relatively cheap, stable, and user-friendly integrated circuit for both monostable and astable applications. Since this device was first made commercially av...

Operation of 555 Timer Circuit Under Radiation Filed

The 8-pin 555 time rs were exposed to 1,2,3,4, up to 5 Mrads gamma doses, using Co 60 as a gamma radiation source, with a total absorbed doses 5Mrads , the output of the chip, as a square wave indicate that , the electromagnetic wave (gamma radiation) affect in the operation of the timer, as : the parameter changed during radiation noise in the generated square wave, frequency (f) and duty-cycl...

LM555 and LM556 Timer Circuits

Detecting Alarm Sounds

Alarms such as phone rings, smoke alarms and sirens are an important component of the acoustic world, designed to convey urgent information in an efficient and unambiguous manner. We are investigating automatic recognition of this class of sounds both because of the practical applications for the hearing impaired, and also because alarm sounds are deliberately constructed to be easily heard, ma...

Simulation Studies on a New Intelligent Scheme for Relative Humidity and Temperature Measurement Using Thermistors in 555 Timer Circuit

This paper presents a novel and cheap electronic version of wet and dry temperature hygrometer The instrument is centered around a 555 timer, operated in astable multivibrator mode. Two thermistors with negative temperature coefficients (NTC) serve as the two timing resistors of the multivibrator. These thermistors are used to sense the dry and wet temperatures. The durations of the ‘HIGH’ and ...