1. Materials we need in this project.
2. Circuit diagram.
3. Some steps to make this circuit.
4. Connecting battery.
5. Test it.
Product list:
1 x BC547 transistor https://www.utsource.net/itm/p/382309.html
1 x 220 ohm resistor https://www.utsource.net/itm/p/8294786.html
1 x 100 ohm resistor https://www.utsource.net/itm/p/8294784.html
More details, pls check the video on Youtube: