LED flasher circuit schematic diagram can be build shown below:
To build this circuit, 9-volt battery can be used used as a power supply.
and also od corse you can use a DC power supply. if you have an adjustable suplly just adjust it 9 volts.
Do not connect more than 9 volst the timer IC. It can be damage.
the led conncts to out pin of 3 and do not forget to R4 resistance. its value of 1 kOhm but you can use different resistors for this. the resistance value can be between 470 ohm to 1 kOhm
The LED flashhing is determined by the resistors R1 and R2 and the electrolytic capacitor of C1.
The formulas to calculate these values in our circuit is:
T= 0.7 * (R1 + 2R2) * C1
Thigh= 0.7 * (R1 + R2) * C1
Tlow= 0.7 * R2 * C1