Curcuit 1

components

1- Led

2- resistor 330 ohm

3- two switches

the idea of curcuit: control the led to be on or off in different condition by using the idea of gates

Curcuit 2

components

1- Led

2- 2 Resistors 1 Kohm

3- Transistor

4- LDR

the idea of that curcuit: the led is turned off when we change the value of potentiometer or when LDR don't have light on it so the potentiometer is used as voltage regulator

Curcuit 3

components

1- 2 Leds

2- 2 Resistors 1 Kohm

3- 2 Resistors 10 Kohm

4- 2 capacitors 100 UF

5- 2 Transistors

the idea of that curcuit: the 2 leds are turned on and off automaticity and we control it through 2 capacitors we use