Izindaba: Ikhasi 8- 9. Emhlabeni wonke sibhekene nenzukayizeki engalawuleka yezonotho engazange ibonwe kusukela isikhathi. I wanted to buy some of these "light ropes" to put under my kitchen cabinets. Being the electrical engineer that I am, mostly power supplies, I found that there was a dearth of information about the things. I decided that I would take some data and take a few pictures to make it easier for people to understand more about them. I have submitted six pictures which you can find labeled "Fig. X", where X is 1-6. You can refer to them to help you understand my written description. I'm a big believer in a picture conveying information far better than any combination of words.How does it work? If you look at Fig. 1, you can see a simple schematic of it. There are 3 white LEDs in series with a 150 ohm current-limiting resistor. I call this series combination a "triad" (triad means "3"). When you apply a voltage, it is sufficient to light all 3 LEDs from the single power supply rail, which is recommended to be 12 volts. The rope then repeats this triad configuration every 1.95", which is approximated as 2" although that additional 0.05" is a 4% error and can amount to a large round-off error on a rope length of 5 meters (=16 feet).In Fig. 3 you can see how the triad is arranged on the rope. At each 1.95" juncture, you can cut the rope if you need to. I show this "cut point" in Fig. 4. Note that when you do, you end up with little exposed copper solder "pads" at each end of the cut which allows you to solder small wires to these two ends. Fig. 5 shows you one of those ends where I soldered two small wires to the pads. You must be careful when you make such connections as the copper that you are soldering to is easily pulled up off of its "substrate," especially if you apply a lot of heat to these pads. The pads are quite small, perhaps 0.Read more ›