As the name suggest 555 timer is basically a “Timer”, which create an oscillating pulse. It means for some time output pin 3 is HIGH and for some time it remains LOW, that will create a oscillating output. We can use this property of 555 timer to create various timer circuits like 1 minute timer circuit, 5 minute timer circuit, 10 minute timer circuit, 15 minute timer circuit, etc. All we need to change the value of Resistor R1 and/or Capacitor C1. We need to set 555 timer in Monostable mode to build Timer. In monostable mode, the duration for which the PIN 3 would remain HIGH, is given by the below formulae:
T = 1.1 * R1*C1
So to build 1 minute (60 seconds) timer we need resistor of value 55k ohm and capacitor of 1000uF:
(1.1*55*1000*1000)/1000000 = 60.5 ~ 60 seconds.
A variable resistor of 1M is used here and set on 55k ohm (measured by multimeter). We can easily calculate the resistor value for 5 minute, 10 minute and 15 minute timer circuit:
5 Minute Timer Circuit
5*60 = 1.1 * R1 * 1000 uF
R1 = 272.7 k ohm
So to build a 5 minute timer circuit, we would be simply changing the resitor value to 272.7k ohm in above given 1 minute timer circuit.
10 Minute Timer Circuit
10*60 = 1.1*R1*1000 uF
R1 = 545.4 k ohm
Similarly to create a 10 minute timer we would be changing the resistor value to 545.4 k ohm.
15 Minute Timer Circuit
15*60 = 1.1*R1*1000 uF
R1 = 818.2 k ohm
As per above calculations, for a 15 minute timer circuit, we need the value of resistor to 818.2k ohm.
We should note here that we have used LED at reverse logic, means when OUTPUT pin 3 is low, LED will be ON, and when OUTPUT is HIGH then LED will be OFF. So we have calculated OFF time above, means after the calculated time LED will be turned ON. LED will be ON initially (OUTPUT PIN 3 LOW), as soon as we press push button (trigger the 555 via TRIGGER PIN 2), the timer will start, and LED will become OFF (OUTPUT PIN 3 LOW), after the calculated time duration, PIN 3 will again become LOW, and LED get turned ON.
Sooooo, for how long does it remain lit up?
As we have used 555 timer in Monostable mode, it will remain ON untill the next trigger (button press). Here, ON state is Stable state and OFF is Unstable state.
i want out put from 555 like 10 min ......30 min square cycle
Can this be used to turn off a signal? ie. could I use it to turn off a switch instead of being ON.
We have connected the LED in reverse logic here. To Turn On the LED just connect the positive terminal of LED to PIN 3 of 555 and negative terminal to Ground.
Dear Abhishek / Jayant,
I want the circuit to switch ON the LED / motor say once in 24 hrs and automatically switch OFF after (say) 30 secs or 1 min (after switching ON). How can this be achieved.
555 Timer IC is not reliable for timers, greater then 10-15 minutes, you should check out IC 4060B for larger duration like 24 hours.
Hi, I tried the 15 min timer with the reverse logic(LED is off before the trigger is pressed,but as soon as I power the circuit,LED blinks and is OFF after that irrespective of trigger button being pressed.
Thank you very much for your explanation. It looks great to me, however, is it possible to make the blinking LED (OFF for 2min and ON for 50 sec)? I do not know how to circuit it. Please kindly help me.
how to discharge battery after 1 min automatically
It is a nice work. I would like to use the circuit to control an incubator, how do I go.abut it?
Hi thanks for your time and effort to help other great job thank you . I'm looking for a timer 10 minute on and reset for 10 minutes ago so 10 on reset 10 off then back on in ten then reset for another around . I hope I'm. M a king Spence I'm a ham radio operator and we have to I'd our station ever ten minutes as long as we are on the radio.some people have burned a chip w I th there call sign I n it . But I could us flash ing red leads I'm not the best at stuff. Like this what do you think .. or a pick buzzer be better or b o th ? Tnx for ur time
Thank you for your work sir, Please I want to drive a relay instead of the
LED, can you help me?
You can use Relay Module and connect the output of 555 to relay module like explained in this article: Automatic Staircase Lights using PIR Sensor and Relay
Really bad writing in this, thats not a LED symbol, you confused R1 with RV1
I want to turn on my certain circuit for 30 minutes and after 30 minutes i want it to be off state. Does this circuit can sort out my problem. Moreover, I want the output of the timer circuit to be 14V, is it possible?.
how to make a timer circuit in which the switch is triggered and the light remains on around 30 sec and off automatically
Connect the LED in opposite direction and make the timer of 30sec using given formula.
can i use this circuit to make 30 min timer? or should i use another ic?
For 30 minutes IC 555 is fine, but 555 Timer IC is not reliable for greater time duration you should check out IC 4060B for larger duration like 24 hours.
how to make a big display with led strips 1 minute with 12v. can you help with the schematic. digit length should be 12 inch hieght and 6 inch wide
Error in schematic, R1 must connect to pin 2 of the 555 to keep Trigger pin 2 high untill you push the switch!
As we know that cooler have a water pump which is used to regulated the water from bottom to top.i want to create a timer circuit which is used to on off the pump at a time period of 1 min.a running pump off after 1 min it's on and again off after a 1min.,this process have still continue till the cooler is on...
It can we possible or not...
Yes it is possible..
I want an electronic timer that will accurately time up to five minutes in one-minute steps before giving an audible (pulsing) or visual (flashing LED) warning that time is up.
Thanks for the wonderful post here. Please I want to build a timer circuit that will be activated by another circuit and the timer circuit should run for 5minutes before turning off automatically. A manual override can also reset the circuit to make it ready for another triggering. Please can I modify this circuit to achieve that? It's more like a delay circuit with automatic and manual reset. Thanks a lot in anticipation of your kind assistance.
I am using two relay in my circuit using 555 timer IC. is it possible that when i switch on the power and then after 30 second both relay will operate at once and after 10 second of that one relay goes off and other remains on
Please help me with this circuit..
It is possible but circuit will become complex, you may need to use 2 or 3 555 ICs and Op-amp, better use some Microcontroller.
i want to know applications of one minute timer circuit.reply asap...thanks
Dear can i use it to control time for a washing machine or some more things like that
There are flaws with the circuit, the 10K resistor top left is simply connected all the time between +9V and ground -ve rail thereby drawing power for no useful purpose, you need to connect 10K bottom leg to the pin 2 of the 555 timer, so that it is held at 9V+ through this 10k (pulled high) so when you push the switch then pin 2 goes low (-ve) to trigger.
secondly if you use bigger capacitors like 1000uF, your timings are going to be miles out, as there is usually very large leakages on higher the capacitor values are, so this circuit may not time if you use very large value capacitors, one should make sure the leakage current is less than the timing current through the variable timing resistor.
thirdly, when the timer trips, the large 1000uF cap will have stored so much charge on it, and all of it will be discharged when next arming the timer, this means all of that energy stored in the cap will dissipate suddenly when you press the button and can cause failure.
Can i make this led connected in a manner,so when i push the button it will be "ON" for 5 minutes.
Are you sure that R1 is connected across the Vcc and Gnd rails? I think one end should be connected to Vcc and the other one to Pin2, to keep it high, and when you trigger the pin, then you make the low trigger impulse connectig Pin2 to Gnd. No? Thank you
I need to make a circuit that when the switch is momentary pushed, it starts the timing circuit on for 15 seconds, however, if the same button is pushed again within that 15 seconds, it cancels the timer and turns the output off. push it again and starts the 15 seconds on again. so its using one switch to start and stop the timing circuit. i cannot seem to figure out how to do it using only one switch. can anyone help me?
I really love this and I need someone to put me through
Why where did you get stuck?
I saw in a book that a capacitor of small voltage is connected to control voltage. Is it necessary for the usage of 555 timer in monostable mode
It is good practice to use it, but its optional
What will happen to circuit if the key is permanently closed?
The timer will go on for ever. It will turn off after 1 minute once you open the key
Hi in the above circuit provided, the resistor R1 should be connected directly to the pin.2 of 555.Then switch to GND from pin.2
Why? I think it would work either way
Hi, do you have a fully component list.
What type of button do you use? And LED?
With spesification like how much current it can take before it breaks etc.
You can use anything it does not mater much
Hi. Maybe u could help me. This project is for an airsoft game. I need an alarm to go on every 5 minutes , and stay on for like 5-10 seconds.
Unfortunality, We implemented this circuit design on Proteus/ISIS but it doesnt work :(
What is your suggestion?
I need to achieve 5 minutes on 15 minutes off.. How to adjust the off time
Is it possible for me to make my timer circuit to be remotely powered? How
How can I make a circuit that turns on after 25-30 minutes and stays on for 5seconds then turn on again after 5minutes
I think your application needs a microcontroller
Hi, thank you very much for this very helpful circuit. Can I ask a favor? Can you please modify the circuit so that it will use a series of LEDs, one for 1 minute, another for 3, for 5, for 7 and 10? Thank you very much in advance.
I have tried this circuit, i have wasted more than 10 LEDs, then i have used an 1k resistor for the LED, then also the circuit is not working what can i do for it.......??????
I need to make a circuit that i can put a timer on for 1,2,3,...,10 minutes then once the time is over whatever device is connected to the circuit will automatically shutdown/turn off. Is there anyway i can modify this circuit to match my needs?
It is bad form to leave the trigger input (pin 2) floating. It should be held high by R1. Then when you press the button pin2 will be grounded, starting the timing process. Move the lower connection of R1 to the right side of the switch.
R1 10K RESISTOR IS CONNECTED BETWEEN +VCC AND GROUND TOGETHER WITH PUSH BUTTON SWITCH.
THIS IS WRONG.
R1 10K RESISTOR SHOULD BE CONNECTED FROM +VCC TO PIN 2 OF 555 IC, AND PUSH SWITCH SHOULD BE CONNECTED FROM PIN 2 OF 555 IC TO GROUND.
THE CIRCUIT WORKS THIS WAY
I changed to the 545.4 resistor to try and make the timer 10 minutes but it is still only lasts one minute. Is there something else I should change? Maybe the capacitor? (I'm using a 1000uF)
I want a circuit that will delay before turn on permanently. And also a circuit that will turn on for some seconds and turn off permanently.