this is a 555 timer it's introduced in 1971 so some people may think that it's absolete inaccurate or incompatible with modern Electronics but this is not true it's versatile and it's still used by hobbyists and professionals this video is not about the IC itself or its inner structure or other try to stuff but in this video we are going to dive into the application of this cute IC and explore six project object s based on 555 timers from a simple blinking LED to modulating infrared Rays uh object detection on garage doors in fact or making reciprocating mechanisms actually we are going to see what we can make using this IC and how it can help us make awesome things by the way we will learn three modes of operation of this cute IC in the heart of six simple projects I promise it's worth your time to watch it till the very end suppose that we have something that has to turn on and up periodically like a siren a warning light whatever how do you make it I know the first application of 555 timers is so predictable I guess most of you know what I'm going to describe application number one making a blinking LED one of the most popular application of 555 timers is to use them to make a blinking LED I call it a hello world project for 555 timers it can be used to indicate a certain situation in a project like caution or danger by the way you can replace the LED with a relay to use the circuit to turn on and off almost everything anyway let's dive into the world of 555 [Music] timers this is the simplest circuit to make a blinking LED using 555 timers just connect pin 4 and pin 8 to VCC connect pin one to ground connect pin 2 to pin six place a capacitor here at Pin five like this place another capacitor between pin 1 and pin two place a resistor between pin six and pin 7 and place another resistor between pin 7 and pin 8 then the IC will generate pulses to Blink the LED at Pin 3 555 timers typically operate within a voltage range of 4.5 volts to 15 volts however it's worth noting that there are variations and different specifications based on the manufacturer and specific model always refer to the data sheet for precise information anyway I'm going to set up this circuit get un [Music] tested as you can see the LED is blinking you can change the duration of on time and off time of the led by changing the value of R1 and R2 resistors and C capacitor these are formulas for determining the exact on and off times but there is an important Point here you may use these formulas for determining on time and of time but you should expect different on time and of time than the values provided by these formulas because of the tolerance of the external components this is the disadv percentage of 555 timers its uh accuracy depends strongly on tolerance of its external components anyway when the IC is repeating pulse generation for example making an LED turn on and off periodically and automatically it's operating in a stable mode application of as stable mode is not limited to a a blinking LED you can imagine plenty of other applications for example generating sounds application number two making sounds humans can detect sounds in a frequency range up to 20 khz 555 timers can generate pules up to 2 mahz so it should be very easy to generate human audable sounds using 555 timers let's make it the principles are the same as the blinking LED but we have to increase the frequency I think 5 Kilz will be a good choice 5 kerz means that there are 5,000 pulses in a second each pulse has to be 200 microc I mean the on time plus the of time have to be equal to 200 microc this 200 microc is the signal period from the definition of period we know that T1 + T2 is equal to the period so T1 + T2 is equal to 200 100 microc by replacing the T1 value and T2 value I got this equation by assigning 22 n to capacitor c i got this equation where R1 + 2 * R2 is equal to 13,18 ohms here I have chosen 560 ohm for R1 so R2 has to be 6.28 KMS I haven't 6.28 kiloohm resistor my workshop so I'm going to make it by using other [Music] values as you can see the output frequency is around 6.9 khz because of Tolerance of the external component values anyway this frequency is okay okay for now if I connect the speaker like this to the output we can hear the sound here this is the beep sound around 6.9 khz coming out of the speaker we can produce plenty of frequencies at output or even play music just by changing the value of external components you can make even more interesting things using G speak here and a 555 timer in ASA mode something like police siren ultrasonic pest animal repellant metronome Etc just by changing the frequency anyway the application of 555 timer in aable mode is not finished yet you can make a garage door sensor using 555 timer in ASA mode how it is possible I will explain but before that I want to introduce the sponsor of this video pcb.com I'm proud to introduce p PCB way because they are Professionals in manufacturing pcbs 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object a person pet or vehicle the receiver detects the interruption and Signal the garage door opener to stop and reverse its movement preventing the door from closing on the object this helps to prevent accident and damage to people pet property or Vehicles here we have an infrared transmitter diode on one side of the door that emits invisible infrared beams and there is an infrared receiver diode on the other side of the door when an object blocks the beam transmitted by the transmitter the receiver detects the interruption the concept is really simple but you may wonder what it has to do with 555 ERS let me explain this is an infrared generating diode it works just like an ordinary LED if I apply voltage to it leads it start generating infrared beams and this is an infrared receiver diode when the infrared light hits this receiver the receiver diode detects the infrared light and converts it into an electronical signal which can be processed by electronic circuits or devices let me test it [Music] as you can see in a normal situation the resistance across this receiver is 2.5 kilms but when an obstacle interrupts the light the resistance acoss this receiver reaches 25 26 kiloohms but this is not enough to make a garage door sensor because there are plenty of infrared emitting sources in the environment sunlight light bulbs florescent lamps and almost anything that creates hit like your car or even your body the receiver just receives the aggregate of all infrared lights no matter who the transmitter is if the system relies on the existence or level of the infrared light in the environment it will not work properly because when the light emitted from the transmitter is blocked by an object the receiver will still sense the infrared light from other sources and it will fail to detect the interruption so we have to think of other solution what if the transmitter blinks instead of generating solid infrared light I think it should work because natural infrared sources in the environment are generating solid infrared light and if the intended transmitter generates pulses it should be distinguishable the transmitter circuit has to generate pulses and receiver circuit has to detect the specific frequency generated by the transmitter so the transmitter and the receiver must agree on a specific frequency 38 khz is a popular and widely used frequency for infrared communication meaning that the transmitter is blinking 38,000 times per second here is where the 555 timer comes into play we have to configure the 555 timer to generate 38,000 PES per second and build another circuit at the receiver to detect that specific frequency generating 38 khz signal at the transmitter is a piece of cake using 555 timers the big problem is the receiver we need a complicated amplification and filtering circuit at the receiver to detect the 38 khz signal in the environment which is not subject of this video but there is a simple way to bypass the complicated process of Designing receiver circuit it's to use a three pin infrared sensor these two pin receivers can only sense the intensity of infrared light in the environment but these are three pin receivers that detect the existence of thir 38 khz infrared frequency in the environment all the amplification and filtering circuitry needed to detect the 38 khz signal is integrated into this IC it is simple to use you just need to apply the proper Supply voltage to it VCC and ground Terminals and then it's done and the circuit is ready to use on the transmitter side we just need to set up as stable mode 555 timer and set R1 R2 and C [Music] [Music] is about 38 KZ now is the time to place this infrared transmitter at the output of 555 timer here at Pin 3 now the transmitter is emitting 38 khz infrared signal and the receiver receives that and turns this led on meaning that the 38 khz signal is hitting the sensor when an object interrupts the 38 khz signal look this led will be turned off by the sensor the circuit acts like a remote controller when the transmitter sends a 38 khz signal the LED turns on from a distance that's awesome also this sensor can be used in many other applications like what application number four data transmission when the transmitter generates a 38 khz signal the LED turns on at another circuit and when the transmitter stops generating a 38 khz signal the LED turns off this is enough for transmitting any type of data command sensor values or even Samsung [Music] images I'm going to connect the push button to pin 4 of the 555 timer like this this instead of connecting it directly to the VCC by pushing this button the 555 timer is activated and it starts to send a 38 KZ signal consequently the receiver receives the 38 khz signal and activates the LED actually this a structure forms a remote controller or even a data line [Music] you can apply a Serial data signal like this to enable pin a 555 timer and then you will get the same data signal at the output pin of the receiver from a distance you can send almost everything 555 timers are analog in nature but they can be used in digital circuits anyway the application of generating uninterrupted pulses does not end here there are endless other usages generating pwm is a nice example pwm is used in many control tasks however for sensitive control tasks it's better to use more precise devices like microcontrollers to generate control pulses anyway the next next application of 555 timers is when we need to turn something on manually but after a certain amount of time it should get turned off automatically application number five ventilation no matter where you are going to ventilate a bathroom a kitchen a greenhouse an athic anywhere you can employ a tiny and cheap 555 timer in its mono stable mode what's the mon stable mode let me explain the second mode of operation of 555 timers is monostable mode in monostable mode the 555 timer generates only one pulse when pin two is triggered using this button the WID of this pulse depends on the value of this resistor and capacitance of this capacitor and it's calculable using this formula for [Music] example [Music] by assigning 100 microfarad to capacitor and 27 kiloohms to the resistor the T has to be 2.7 [Music] seconds as you can see by pressing this button the LED turns on for 2.7 seconds however there may be some errors because of the tolerance of the external [Music] components the pulse WID in the previous example can be increased up to several minutes by choosing proper values for the resistor and the capacitor this mode of operation of 555 timers can be used in many other applications if you have an idea about this mood of operation please share it in the comment section below anyway let's move on to the last application application number six Direction keys in some projects you may reach a point where you need two separate signals to change the state of the system for example when you need a reciprocating mechanism in such a case you can use a 555 timer that is configured to operate in bable [Music] mode this is the simplest bi stable operation Moda 555 timers here we have two push buttons the first one is to activate the LED at the output and the second one is to deactivate the LED at the output [Applause] [Music] when I press this button the LED at the outut turns on and by pressing the other button the LED turns off by using this simple circuit instead of the LED circuit we can make a back and forth movement using a single DC motor uh look here there is a relay here actually it's a two contact relay the component is this it has eight pins the relay pins are connected to the motor and Supply voltages in this [Music] way by using limit switches like the this instead of these push buttons you can make electrical back and forth mechanism using 555 timer then the moving part of the Machinery hits this uh limit switch it will cause the switch to reverse the motor and invert the moving part Direction after that the moving part will be in the way of hitting the second limit switch the back and force mechanism was the last example in this video but there are plenty of other applications of this tiny cheap and flexible IC that you can learn and explore anyway we have reached the final moments of this video I hope you enjoyed this video and learn something new thanks for watching if you enjoyed this video please give me a thumbs up and if you like this video make sure to subscribe for more