555 Circuits

IC 555 Timer Circuits Hobby Projects Astable Monostable Bistable Capacitor Resistor IC 556

555 Timer

555 Timer IC

The 555 Timer is the one of the most versatile linear hybrid Integrated Circuit (IC) which is used in variety of  pulse generation, timer and oscillator applications. In 1972, Signetics Corporation first introduced this device as the SE/NE 555. Now a days it is manufactured by many companies in bipolar and in low power CMOS. It is widely used in electronics circuits as it is very simple and cheap method to produce accurate and highly stable time delays. It can be used for various [...]

555 Timer

Astable Multivibrator using 555 Timer

An Astable Multivibrator is an oscillator circuit that continuously produces rectangular wave without the aid of external triggering. So Astable Multivibrator is also known as Free Running Multivibrator. I have already posted about Astable Multivibrator using Transistors. Astable Multivibrator using 555 Timer is very simple, easy to design, very stable and low cost. It can be used for timing from microseconds to hours. Due to these reasons 555 has a large number of applications and it is a popular [...]

555 Timer

Generating PWM Using 555 Timer IC

In applications like Motor Speed Control, LED Brightness Control we may want to vary voltage given to it. Most often we use a variable resistor for that. The main problem with this control is the power dissipation across the variable resistor. This problem can be avoided by using Pulse Width Modulation (PWM). In this method the average voltage delivered to the load is controlled by varying the duty cycle of the rectangular wave.  Here I'm going to discuss one of the simple technique to [...]

555 Timer

Monostable Multivibrator using 555 Timer

Monostable Multivibrator is also known as One Short Multivibrator. As its name indicates it has one stable state and it switches to unstable state for a predetermined time period T when it is triggered. The time period T is determined by the RC time constant in the circuit. Monostable mode of 555 Timer is commonly used for generating Pulse Width Modulated (PWM) waves. Circuit Diagram This is the circuit diagram of 555 Timer wired in Monostable mode. 8th pin and 1st pin [...]

Dancing Light using 555 Timer

A dancing light can be easily constructed using a 555 timer wired in astable mode. Please read the article Astable Multivibrator using 555 Timer before continuing. This circuit blinks two LEDs alternatively with some delay and it can be easily modified to include more LEDs or for controlling incandescent lamps. Time period of oscillation is determined by RC time constant of the circuit. Circuit Diagram 1st and 8th pins of 555 timer are used to provide power, Vcc and GND respectively. 4th is the Reset [...]

Output - FM Generation using 555 Timer

FM Generation using 555 Timer

In communication systems, Frequency Modulation (FM) is the process in which information (message signal) is transmitted over a carrier wave by varying its instantaneous frequency. The difference between instantaneous frequency and central frequency of the carrier will be directly proportional to the instantaneous value of the amplitude of message signal. 555 Timer wired in Astable Mode can be used for generating Frequency Modulated (FM) waves. Please read the article Astable Multivibrator using 555 Timer for more details about the circuit. In astable multivibrator we [...]

TSOP17XX Pin Out

IR Transmitter and Receiver using 555 Timer and TSOP1738

IR Transmitter and Receiver pair can be easily made using 555 Timer, IR LED and TSOP1738 IR Receiver. This can be used for remote controls, burglar alarms etc. TSOP1738 is a very commonly used IR receiver for PCM remote control systems. It has only 3 pins, Vcc, GND and Output. It can be powered using a 5V power supply and its active low output can be directly connected to a microcontroller or microprocessor. It has high immunity against ambient [...]

555 Timer

Bistable Multivibrator using 555 Timer

As the name indicates, a bistable multivibrator has 2 stable states. It can be switched from one state to another by providing an external trigger. It can be used for storing a binary digit (bit) as it has 2 stable states (0 or 1). So it is commonly used in digital circuits, where it is named as Flip Flop or Latches. A bistable multivibrator can be easily constructed using the most popular and low cost 555 Timer IC. Circuit Diagram - 555 [...]