1. A rodent chewed up an LED socket on a 100 light, warm white 3.2 V light string. I want to replace the socket with a resistor to keep the string within its voltage and current parameters. What would be the correct resistance and wattage of the resistor? The resistor would be encased in marine shrink tubing and secured with a wired support. led. 1.8mm LED. The 1.8mm mini LED has a tip that is 1.8mm across, and below that, a square base. If you are putting LEDs into your project from the inside, you do not need to have the whole LED showing to get a nice lighting effect. Use a 5/64 drill bit to have just the small tip of the LED showing. I see that a lot of people use pre-wired 0402 or 0603 leds with a through hole resistor encased in shrink wrap in one of the leads, and that is all well and good, but I would like to know if there are SMD leds (specifically 0402 or 0603) that have an integrated resistor, so I can connect them directly to 3.3V or 5V and not burn everything down Assuming that a single green LED with 10mA forward current should have a constant operating voltage of 5V, the series resistor R V equals (5V -V F,10mA )/10mA = 300Ω. The forward voltage is 2V, as indicated by a graph of typical operating conditions found in the data sheet (Figure 2). Figure 1. Standard red, green, and yellow LEDs have forward For the first time I want to include some SMD LED (0603) vom LCSC. However, I am not sure about the choice of resistors. Of course, I did my homework and looked up the forward voltage and the corresponding current and calculated the required resistor value for 3.3 V supply voltage. However, compared to other PCBs desings I saw, the values seem Unfortunately as the temperature rises, LED will draw more current at the same voltage - which means even higher temp, higher current, malfunction. This is why high-power LEDs should be always used only with constant-current source and not just series resistors. You can find many LED driver ICs, to which you need only few components. There are usually recommendation for soldering e.g. temperature, time, process and even time profiles. A 946C hotplate is a must-have tool for SMD soldering. I usually set it to ~160C, leave boards on there for a few minutes, and use the hot air wand (~220-240C) to flow the solder. Leo.. \$\begingroup\$ LED strips usually use multiples of 3 LEDs plus a resistor across 12v. So IF each LED drew 60 mA you'd get 60 mA x 12V per 3 LEDS or 6A for 300. BUT a 5050 pkg in a LED strip probably has 3 x individual LEDS in the pkg rated at 20 m each or 60 mA the 3 in parallel or 20 mA in series. Which gives the answer I gave. 6M6H.

do smd leds need resistors