Many electronics circuits and projects for learning in simple ways.

Monostable multivibrator using 555 timer

These are many Monostable multivibrators using 555 timers. We use them as timer circuits to control a load. For example, LEDs, or driver relay. Which trigger them by a normal switch. Please look at more below. I hope you are happy!

Monostable multivibrator using 555 timer

Here is the circuits diagram you can make that.

1. Simple 555 timer with LED display
2. Basic Timer Control circuit using NE555
3. 555 IC Timer control relay Switch
4. Egg timer circuits using IC-555

The 555 is good at making the timer. We often call it, 555 timers. It may be unique features of 555.

It is very easy to use. Just add a resistor and capacitor each one.

We so get a simple timer that can set the time as you want.

In the circuit below, take the 555 in the monostable multivibrator or the time delay circuit. It has the operation status of 2 level. First, low voltage (logic “0”). Second, high voltage (logic “1”).

Simple 555 timer with LED display

Simple scheduling tool

 

In the circuit above. When press the switch S1. Pin 2 of IC-555 will be shorted to the ground. It is the trigger for IC-555 to active with the low voltage or logic “0”.

Then, the output pin 3 of IC gives the high voltage. It is the same as the power supply voltage. So it makes LED1 glow up to show the time working.

This time can be set by changing the value of R2, C1, and VR1.

Below is a simple math equation. For those who want to calculate the right time.

Time = 1.1 R2 x VR1 x C1

Also, You can set this time easily by adjusting the VR1.

Basic Timer Control circuit using NE555

Basic Timer Control circuit using NE555

As circuit below, we use LED display to show the timer circuit. But if we need to use others load. For example, lamps, motors, and more. In principle, the maximum current output of LM555 is about 200mA.

It has many ways to drive the high current load. First, using transistors, easy and cheap. But it cannot use with AC load. Using relay is the best way we like at all time. IC555 can drive the relay directly without helping of a transistor. So easy and useful.

In the circuit above, to begin with, Press the pushbutton switch-S1 just a brief moment. To start the Timing Cycle. The relay will be pulled in. The current flow to the load. Until finishing the timing delay. The relay does not work.

R1 and C1 control the delay time. If more capacitance of C1, more time. It is same as above circuit. This circuit also responds to a logic pulse. Have fun with this simple timer circuit.

555 IC Timer control relay Switch

555 IC Timer control relay Switch

This circuit is similar to the second. It is another idea of 555 timers with a relay switch.

Egg timer circuits using IC-555

Egg timer circuits by IC-555

This is mini timer circuit that interesting. It is called the Egg Timer circuit. Also, I use The famous 555 IC, LM555 or NE555 or equivalent. Using VR1 to adjust the timing of the egg timer.

The S1 is a selector switch.

First, set S1 to “standby”. Pin 2 of IC open up. IC does not work. The buzzer will be silent. While the current flows R1 to charges in C1.

Second, set S1 to “time”. In briefly, C1 discharged, Pin 2 closed to turns IC-555 on. The buzzer will be silent until the delay is complete. Then, the buzzer will emit alert us immediately.
Increase C2 or VR1, R2 for longer delays.

This Post Has 17 Comments

  1. “Minute Timer with alarm by IC555”

    Thanks very much for you job,
    But I think there is small error in this circuit, you must connect the C1 with the pin 5 not with pin 1,
    but else all doing well , I try this circuit & I found simple & practical.

    Best

  2. Hi i would like to make a timer that i can install into radio controlled aircraft. If one were to crash the aircraft and cant find it then after 15 min a buzzer will go off. it needs to run on a small 12v battery. Could anyone please help.
    Thank you

  3. To Philip -you posted 6 months ago. Anyways, use the first circuit. and just eliminate the switches and 5, 10 and 30 minute resistors???? Pretty obvious. You asked for help but noone has any way of contacting you except through another comment. Try google, try an electronics forum. Try looking at the schematics on this page. Try learning basic electronics. The most common 12v battery is a car battery. Try strapping that to your goddamn crappy RC plane.
    regards
    Steve

  4. can u pls tell me how to calculate the resistor n capacitor values for 10 sec dealy n pls give its relationship

  5. how much voltage and current will be there in the output where buzzer is placed. Is the same circuit could be applied for ON-OFF a bulb of 12V??? what should be the supply voltage in such a case???

  6. Hi Sellam,
    Thanks for your correction, I first connected it with the error and after I read your comment, I corrected it (by connecting the C1 with the pin 5 not with pin 1) but it still did not work. I only used a 470K to have aprox. 5 minutes delay, but it does not work.

    Could anyone help me out please?

    Thanks in advance
    Jack

  7. Hi
    I have a music player in my car that is powered from the ignition but it often fails to start correctly because the power gets cut briefly when I start my engine. I would like to use a 555 Timer to delay the 12v supply to the music player for about 30 seconds after switching on the ignition. Any help would be appreciated.
    Thanks

  8. I need a basic cct digram for an oscillator;
    24v input.

    Output.
    Off- adjustable 15 to 60+ seconds
    On (pulse) 0,5 sec

  9. Hi

    I like to build a night switch that turns on 4 LEDs. So once it’s getting dark they should turn and keep burning for 3hours. Can anyone help please? Email: info a mxtan com

    Thanks a lot!!!’

  10. Hi,
    I’m finding a auto power on AC circuit.
    It should have a AC input and a AC output.
    It will be always connected to AC, and output AC will be on after a particular time.
    or something like that.
    Do you know something like this?
    thanks

  11. @Steve May24 2013
    You sir are a knob of the highest order.

  12. @kalpesh

    Please try the formula is T = 1.1 RC
    For time you need.
    In the Simple scheduling tool circuit
    For I will adjust VR1 to time need.

    Thanks

  13. ayush
    i want to know how to get 12haur delay by using timer ic

  14. Simple circuits. English so bad cannot understand explanation

    1. Hello, Allen Pitts
      Thanks for your feedback. Yes, my English is poor. I try to rewrite it. I hope my English improve you can understand it.

  15. Hi
    can you help me please !
    trying to make a 12v sports starter to operate a car horn!!
    initiate by a momentary switch. power on for 0-2 seconds thengoes off ready for next start !

    searched everywhere with no luck so far

    Les

  16. you gais ar realy good, but what should i do if i want to make a bomb?

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