iWriting線上寫作網

Be prepared for some long and tedious steps. Carefully soldering 64 individual LEDs, each not much larger than a grain of sand onto thin and uncooperative wires takes patience. 

 

Before starting, measure out your umbrella and plan where each of the LEDs will go. This umbrella will have 16 spokes radiating out from the center, each spoke having 4 LEDs. I chose to have 4 different sets of LED spacing (8 of each set) to make a pseudo random looking pattern. I set the LED spacing set so they're generally closer together towards the outside of the umbrella in an effort to make the LED distribution reasonably even throughout the surface of the umbrella. 



Get a large board (wider than the radius of your umbrella) and hammer a bunch of nails along the sides so that you can string up/stretch out your single-strand copper wires (2 wires to each nail). Place masking tape and/or mark off the points at which you will be soldering the LEDs. Leave some extra lengths of wire at each end in case you need some extra length once it comes time to actually install them onto your umbrella. 



Place some masking tape under the wires to prevent burning the board (in case you ever want to use it for some other purple) and more masking tape to hold the wires down in place as you solder. My wire was lacquer coated, so I had to first burn it off at the points where the LEDs will be added with my soldering gun and hot solder. (You may try scraping it off instead, or using a wire stripper to strip it off.) Once the wires are 'tinned' with solder, try to wedge an LED between the two. Be careful to place all LEDs in the same polarity!! 



Time to solder your first LED. I tried to apply some masking tape onto the wires so that they pinch the LED in place - makes it easier to solder the LEDs in they they're not always moving around. With a very quick, light touch, touch both sides of the LED with the hot soldering tip and the solder coating the wires & tip will flow into the LED contacts. If you're not sure you got it, hook up 3V (two AA batteries) to the wires hanging off the board and see if the LED lights up! Once you get the hang of it, move on and do the rest of the LEDs. I soldered mine in two sets - half of the wire/LEDs on the board at one time (16 'spokes') and the other half after finishing the first. 



After all the LEDs were soldered in, I applied power to the board/wires to see all the LEDs light up in their glory :) This is also a good time to determine how many volts you want your umbrella to run on, and what value variable resistor you want to use for dimming. I decided on 3 AA batteries (4.5 Volts (or 3.6 volts if using rechargeable batteries)) and a 750 Ohm variable resistor.

文章裡有一個有趣的單字spoke，但是竟然加了"s"，speak的過去式加了s，spokes到底是什麼東西呢？一起來認識新單字吧！

tedious..........冗長、乏味
grain..........穀粒
uncooperative..........不合作的
spoke..........輪輻(腳踏車輪的骨架或是雨傘的骨架)
radiate from..........從中心向外延展
pseudo..........假的
radius..........半徑
scraping..........削去
strip..........剝去
polarity..........極性