Here is a simple circuit of the star of Christmas light that can be easily built, even for a beginner. The main advantage of this circuit is that it requires no transformer or IC. Components such as resistors R1 and R2, capacitors C1, C2 and C3, diodes D1 and D2, and zener zD1 are used to develop a fairly constant voltage of 5V DC power that provides the current necessary to activate the triac multivibrator circuit and activate BT136 through LED1. The multivibrator circuit is constructed with two transistors BC548 (T1 and T2) and some passive components.
The frequency of the multivibrator circuit is controlled by the capacitors C4 and C5 and resistors R3 through R7. The output of the multivibrator circuit is connected to the transistor T3, which in turn drives the triac through LED1. During the positive half cycles of the multivibrator output, the transistor T3 is driven triac BT136 and lit the lamp. This circuit is an estimated cost of R 75
The frequency of the multivibrator circuit is controlled by the capacitors C4 and C5 and resistors R3 through R7. The output of the multivibrator circuit is connected to the transistor T3, which in turn drives the triac through LED1. During the positive half cycles of the multivibrator output, the transistor T3 is driven triac BT136 and lit the lamp. This circuit is an estimated cost of R 75
Note:
This circuit directly connected to the netting of electricity, voltage 220V electricity it could sting you. Avoid working in damp and directly with ground.
