[Simple version + upgraded version] Super simple zero power LED night light DIY

    The purpose of DIY is to make a night light with as little cost as possible. There is almost no technical content, just for fun... OK, let's get to the point:

　　Materials needed for DIY:

The white LED light board 　　discarded by the advertising company , the waste network cable, the empty mineral water bottle and jam bottle, the crystal head, a resistor

　　DIY Cost:

　　Excluding labor costs, it’s less than one yuan.

　　Time required for DIY:

　　No more than 1 hour.

　　DIY steps:

First , remove the current limiting resistor on the 　　original LED light board and replace it with a resistor with larger power and resistance.

　　I used a 0.5w 5.1k resistor. In fact, the resistance value can be around 5.6k. Lower resistance values ​​are brighter, higher resistance values ​​are darker. However, it should not be lower than 4.7k, otherwise the LED may burn when the voltage is high . Just change a resistor.

　　Secondly, drill a hole in the mineral water bottle cap and pass the network cable through it.

　　Then connect one end of the network cable to the crystal plug used for telephone lines. The crystal plug has 4 wires, but in fact, only the two inside are enough.

　　Connect the three LED light panels in series again and connect the network cable.

　　Finally, cut the mineral water bottle in half, screw on the cap, and you’re done.

　　Since the circuit is so simple, I won't show it in pictures. I guess ordinary forum users can figure out how to connect it with their toes... No picture, no truth, let's see the effect below.

　　The following is an upgraded version. Because the mineral water bottle is too light and difficult to place, a glass jam bottle is used instead. At the same time, a small switch removed from a waste toy is installed on the bottle cap. The upgraded version is also completed.

　　This is a night light powered by the telephone line. Since the telephone line is always connected, there is no need to worry about power outages. According to my test, there is no problem at all driving 3 night lights at the same time. The reason why the resistance cannot be too small is that when a call comes in, the voltage increases. If the resistance is too small, the current will be large. After the phone is picked up, the current of the night light is too small and it will not light up, but once the phone is put down, it will return to normal. And this night light has no effect on making calls...

　　One last thing to say: the telephone line uses direct current. If the night light doesn't light up when you plug it in, just swap the polarity of the wiring.