Hi,
I am interested to make a very simple circuit. I have DC voltage from 10V to 15V in my home in which i want to add this circuit on it .I want that a 3mm (Red led) may blink after every 1 or 2 sec when it is connected with the circuit.Definitely there will be need of capacitor and resistor etc etc. If any one knows how make to make this circuit with diagram I shall be thankful to him. Currently i am using breadboard for testing and 9 volt batter i am using with it .
Thanks in advance.

 

So, you want a LED to flash when it is connected to your ~12V supply?

The simplest solution is to use an LED with an integrated flasher. Then all you need to do is connect it to the supply.

Alternatively a 555 chip and a few components will flash an ordinary red LED. Or even a discrete relaxation oscillator.

 

Yes i shall connect it with 12.5V DC supple so in that case with 555 chip can someone help me for the diagram .

 

Here's the datasheet for a 555. The circuit you want is Section 7.4.2 Astable Operation. You would connect a 12V LED to the 555 output, or an ordinary LED with a 1k series resistor: https://www.ti.com/lit/ds/symlink/lmc555.pdf.

Alternatively, here's a discrete circuit I have often used. Not many more components than the 555 circuit:

 

about https://www.google.com/search?chann...+red+led+flash+duration+at+dispersed+daylight

an overkill circuit the exact values for resistors depend on both TYPE and instances (hFE values) of the transistors used
you can do by single comparator https://www.ti.com/product/TL391B-Q1 or 18V CMOS Schmitt inverter https://www.onsemi.com/pdf/datasheet/mc14584b-d.pdf ← 6x outputs in parallel gives ? some 50 mA drive ?

 

slight tweak to boostbuck circuit in #4:
added C2 so that LED does not light up immediately (you wanted 1-2sec delay).
added R6 to make LED go fully off (optional).

 

If any one knows how make to make this circuit with diagram I shall be thankful to him.

Is this schoolwork?

 

one low component count option is to use Schmidt trigger NAND gate. then one input can be used to make an oscillator (input to output resistor, input to GND capacitor). the other input can be used to make delay input to Vcc resistor, input to GND capacitor). and bonus is one still gets three more gates for whatever purpose. of not used, connect their inputs to gnd. load (LED and resistor) from output to Vcc.
if the space is concern there are single gate ICs in SMD though they are only good for up to 5 or 6V meaning there would be need to use voltage regulator or zener...

 

Here you go. Adjust R1 for desired frequency.