LM555 - NE555 - Pin Out Diagram

The History of 555 Timer IC – Story of Invention by Hans Camenzind

jojo July 5, 2017 58 Comments
The 555 Timer IC is one of the renowned ICs, in the electronic circles. However, its history of invention is not known to many. This article takes you on a journey of 555 timer IC from the time of its creation to the present day time. What is a 555 timer IC? A 555 timer IC, is a multipurpose integrated circuit chip, that finds its application in timer, oscillation and pulse generation circuits. It is one of the prominent...
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Internal Block diagram of 555-Timer

555 Timer Circuits in Proteus

jojo June 14, 2017 8 Comments
555-Timer is one of the most popular and mostly used ICs. It best suits for timing/timekeeping related circuits. It consists of two operational amplifiers operated in an open loop or comparator mode, RS Latch with additional Reset input, a discharge transistor, an inverting buffer and an amplifier in the output stage. It has a voltage divider circuit with three 5K Ohm resistors in series. 556 is a dual timer IC. The internal block diagram of 555 is as follows....
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PWM lamp dimmer using NE555

admin January 22, 2014 22 Comments
PWM lamp dimmer. A simple and efficient PWM lamp dimmer using timer IC NE555 is discussed in this article. Yesterdays linear regulator based dimmers can only attain a maximum efficiency  of 50% and are far inferior when compared to the PWM based dimmers which can hit well over 90% efficiency. Since less amount of power is wasted as heat, the switching elements of PWM dimmers require a smaller heat sink and this saves a lot of size and weight....
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3 Great Books to Learn 555 Timer Circuits and Projects

jojo February 17, 2014 10 Comments
Any one who is interested in electronics would have come across this IC – 555. It is the one component that is used in many wide range of applications. 555 Timer is used in a variety of applications including monostable and astable multivibrators, dc-dc converters, digital logic probes, waveform generators, analog frequency meters and tachometers, temperature measurement and control devices, voltage regulators etc. So it is essential that you should have a deeper understanding of 555 IC and how it is used in these applications.  The best way...
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555 Timer Projects

555 Timer Circuits and Projects – List of 25+ Simple and Advanced Circuits

john June 14, 2017 5 Comments
We are listing a curated collection of 555 Timer Circuits and Projects published in our site before. We have a large collection of simple and advanced projects using 555 Timer IC. In this article, we have handpicked some really useful 555 timer circuits which will be interesting to electronics engineering students and hobbyists alike. While selecting from the big collection, we have also taken care to add some 555 timer projects which fall in the fun & game circuits...
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Voltage doubler circuit using NE555

jacky January 22, 2014 34 Comments
Description. The circuit diagram of a very simple voltage doubler using NE555 timer is shown here. Here IC NE555 is wired as an astable mutivibrator operating at around 9KHz. The base of the two transistors (Q1 and Q2) is shorted and output of the astable multivibrator (pin 3) is connected to it. When the output of astable multivibrator is low, Q1 will be OFF and Q2 will be ON. The negative terminal of the capacitor C3 will be shorted...
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Police siren using NE555

jacky January 27, 2014 16 Comments
Description. A lot of electronic circuits using NE555 timer IC are already published here and this is just another one.Here is the circuit diagram of a police siren based on NE55 timer IC. The circuit uses two NE555 timers ICs and each of them are wired as astable multivibrators.The circuit can be powered from anything between 6 to 15V DC and is fairly loud.By connecting an additional power amplifier at the output you can further increase the loudness. IC1...
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555 Timer-Ramp Generator

jojo February 28, 2010 3 Comments
Ramp Generator Circuit-using 555 Timer IC We know that if a capacitor is charged from a voltage source through a resistor, an exponential waveform is produced while charging of a capaci­tor from a constant current source produces a ramp. This is the idea behind the circuit. The circuit of a ramp generator using timer 555 is shown in figure. Here the resistor of previ­ous circuits is replaced by a PNP transistor that produces a constant charging current. Charging current...
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555 Timer Oscillator

jojo February 28, 2010 2 Comments
A voltage-controlled oscillator (VCO) using the timer 555 is shown in figure. The circuit is sometimes called a voltage-to-frequency converter because the output frequency can be changed by changing the input voltage. As discussed in previous blog posts, pin 5 terminal is voltage control terminal and its function is  to control the threshold and trigger levels. Normally, the control voltage is ++2/3VCC because of the internal voltage divider. However, an external voltage can be applied to this terminal directly or...
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555 Timer as Monostable Multivibrator

jojo January 23, 2018 38 Comments
Are you familiar with the basics and applications of the 555 timer IC? Are you looking for a book that provides all these basics? If so, CircuitsToday has started an online store from where you can buy books on 555 timer IC, which have been reviewed in detail. You can go through the reviews and buy them here:- 3 Great Books to Learn 555 Timer Circuits and Projects A monostable multivibrator (MMV) often called a one-shot multivibrator, is a pulse...
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