Firefighters say that using a homemade Christmas tree garland is unacceptable. Of course, if it is assembled at random, then they are completely right. But if a homemade garland is made according to certain rules, it may even be safer than a factory one.
Instructions
Step 1
Take an unnecessary cell phone charger. Look at what the maximum load current in milliamperes is designed for.
Step 2
Take a super-bright LED of any color and a 200 ohm resistor that has a power of about 0.5 W. Connect them in series and connect this chain to the charger, observing the polarity. Measure with a milliammeter (also included in the circuit in series) how many milliamperes this design consumes.
Step 3
Divide the maximum load current of the charger by the current draw of one emitter. You will receive the maximum number of emitters that can be connected to it. For reliability, reduce this amount by about a third more.
Step 4
If necessary, extend the charger output cable to extend from the outlet to the tree. Insulate all connections carefully.
Step 5
The chains of series-connected LEDs and resistors, the number of which does not exceed the calculated one, connect in parallel, observing the polarity, and connect to the charger. The wires with which you connect them must withstand the total current consumption of the entire garland for a long time.
Step 6
Re-insulate all connections carefully to avoid short circuits (although most chargers are protected against short circuits, an additional measure of safety will not be in the way).
Step 7
Turn on the garland and make sure all the LEDs are on. Now you can hang it on the tree.
Step 8
It is undesirable to use blinking LEDs in a garland instead of conventional LEDs. Since there is no common controller, they will blink chaotically and abruptly, which can quickly tire your eyesight. But diodes that automatically smoothly (not abruptly!) Change color will do.
Step 9
If you wish, lay out a beautiful panel out of LEDs, for example, similar to the one shown in the title of the article.
Step 10
Do not, under any circumstances, use your homemade garland outdoors. Replace the charger with another immediately if you find cracks on its case. Do not use chargers with covers removed.
