How to Make a Blinking LED using a 555 Timer IC?

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This text explains the circuit design for blinking LED using a 555 timer IC. That is a easy circuit designed to clarify the working and use of a 555 timer IC. This circuit is designed using a low power consumption output device, a pink LED. There are various purposes of 555 timers, usually utilized in Lamp Dimmer, Wiper Pace management, Timer Change, Variable obligation cycle fastened frequency oscillator, PWM Modulation and many others.

Blinking LED Circuit Using a 555 Timer IC

Circuit Elements

  • 555 timer IC
  • LED
  • 9V battery
  • 1KΩ Resistor – 2
  • 470KΩ Resistor
  • 1µF Capacitor
  • Bread Board
  • Connecting wires

Circuit Diagram

The next circuit design explains the design of the blinking LED  (Light Emitting Diode) with the 555 timer IC. Right here on this configuration, the 555 timer IC has linked in an Astable mode of 555 timer operation.

Blinking LED using 555 timer
  • Gather all of the required elements and place the 555 timer IC on the breadboard.
  • Join pin 1 of a 555 timer IC to the bottom. Yow will discover the pin construction of a 555 timer IC within the circuit diagram proven above.
  • The longer lead of a polarized capacitor is the constructive and the shorter lead is adverse. Join pin 2 to the constructive finish of a capacitor. Join the adverse lead of the capacitor to the bottom of the battery.
  • Now quick the pin 2 to pin 6 of the 555 timer IC.
  • Join the output pin 3 with the constructive lead of the LED using a 1kΩ resistor. The adverse lead of LED wants to be linked with the bottom.
  • Join pin 4 to the constructive finish of the battery.
  • Pin 5 doesn't join to something.
  • Join pin 6 to pin 7 using a 470kΩ resistor.
  • Join pin 7 to the constructive finish of the battery using a 1kΩ resistor.
  • Join pin 8 to the constructive finish of the battery.
  • Lastly, join the battery leads with the breadboard to begin the power provide within the circuit.

Bodily Diagram

Blinking LED Bodily diagram

555 timer IC is used to create time distinction in varied purposes. The Blinking LED circuit makes use of a 555 timer in astable mode, which generates a steady output within the type of a sq. wave at pin 3. This waveform will flip LED ON and OFF. The length of ON/ OFF relies upon on the time cycle of the sq. wave. We are able to change the pace of blinking by altering the worth of capacitance.


READ : Different Types of Demultiplexers


555 Timer IC

555 timer IC is a budget, in style and exact timing device utilized in varied purposes. It will get the title from the three 5KΩ resistors which can be used to generate two comparator reference voltages. This IC is operated as monostable, bistable or an astable multivibrator to produce a number of purposes.

555 Timer IC

This IC comes with bipolar 8 pins dual in-line bundle. It consists of 25 transistors, 2 diodes and 16 resistors organized to type two comparators, flip-flops, and high present output stage.

Pin Description

The next is the pin description of the 555 timer IC.

Pin 1-Floor: It's linked to floor as common. For the timer to perform this pin needs to be linked to floor.

Pin 2-TRIGGER: The adverse enter comparator No 1. A adverse pulse on this pin “units” the internal Flip-flop when the voltage drops under 1/3Vcc inflicting the output to change from a “LOW” to a “HIGH” state

Pin 3-OUTPUT: This pin additionally has no particular perform. This pin is drawn from PUSH-PULL configuration shaped by transistors.This pin provides the output.

Pin 4-Reset: There may be a flip-flop within the 555 IC timer chip. The output of flip-flop controls the chip output at pin 3 straight. This pin is linked to Vcc for the flip-flop to cease from onerous resetting.

Pin 5-Management Pin: The management pin is linked from the adverse enter pin of comparator one. The perform of this pin to give the person the direct management over the primary comparator.

Pin 6-THRESHOLD: Threshold pin voltage determines when to reset the flip-flop within the timer. The brink pin is drawn from constructive enter of comparator1.

Pin 7-DISCHARGE: The discharge pin is linked straight to the Collector of an internal NPN transistor which is used to “discharge” the timing capacitor to floor when the output at pin 3 switches “LOW”.

Pin 8-Energy or VCC: This pin additionally has no particular perform. It's linked to a constructive voltage.

Working Modes OF 555 Timer IC

The 555 timer IC operates in modes

  • Astable mode
  • Monostable mode
  • Bistable mode

Astable mode

Astable mode means there might be no steady ranges on the output. Thus the output will fluctuate from high and low. This character of the astable output is used as a clock or sq. wave output for a lot of purposes.

Options of 555 timer IC

  • It operates from a wide selection of power provides starting from + 5 Volts to + 18 Volts provide voltage.
  • Sinking or sourcing 200 mA of load present.
  • The external elements needs to be chosen correctly in order that the timing intervals might be accomplished in a number of minutes together with the frequencies exceeding a number of hundred kiloHertz.
  • The output of a 555 timer can drive a transistor-transistor logic (TTL) due to its high present output.
  • It has a temperature stability of 50 elements per million (ppm) per diploma Celsius change in temperature, or equivalently 0.005 %/ °C.
  • The obligation cycle of the timer is adjustable.
  • The utmost power dissipation per bundle is 600 mW and its set off and reset inputs has logic compatibility.

Thus, that is all about making of Blinking LED using a 555 timer IC. We hope that you've got a higher understanding of this idea. Moreover, any queries relating to this subject or 555 timer based projects, please give your worthwhile solutions by commenting on the remark part under.

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