This is a headlights alarm circuit, when forgot turn off headlight on car. may cannot start car,batteries lose voltage. it warning buzzer using nand gate IC [...]
The 2 tone doorbell circuit, which is an electronic buzzer types,but them has melodic sound than general electric bell. People have seen two tone bell sound
The Door Guard Knob Alarm circuit with touch system. When thief caught on door handle, makes alarm once. Use the the detector capacitance within the body.
This is the cheap fire alarm circuit that Use principle of infrared sensor smoke. When cause events fire. The principle is simple and affordable.
This is an Simple blown fuse alarm circuit for AC line, cause we know immediately when broken fuse circuit and it has a few components so easy build cheap.
Use high frequency out of the piezo speaker and IC-556 is base as oscillator between 22kHz and 56kHz
This projects is safer and more convenient.
The tree is very necessary for humans. Because can clean waste air, as a food, housing, medicine, etc., We should tree planting as well. Water is necessary for the trees.…