1. Steps of wire break alarm circuit.

2. Steps of wireless AC line detector circuit.

3. Steps of light on timer circuit.

Product list:

Product list:

LED   https://www.utsource.net/category/led-lighting-1.html

BC547    https://www.utsource.net/sch/BC547

BC548    https://www.utsource.net/sch/BC548

Capacitor    https://www.utsource.net/category/passive-components/capacitors-1.html

Buzzer    https://www.utsource.net/itm/p/8027239.html

Resistor    https://www.utsource.net/category/passive-components/resistors-1.html

More details, pls check the video on Youtube: