LED Strobe Kit Tutorial
This month we wanted to get a little flashy. Nothing worse that seeing blue lights behind you while driving, right? For this month, we designed a small red and blue LED strobe kit, that should scale closely to be able to be installed on those LEGO vehicles some of us still build!
First, you should refresh yourself on soldering safety!
WARNING: SOLDERING IRONS ARE HOT. SOLDERING IRONS ARE NOT TOYS. ALWAYS WEAR EYE PROTECTION WHILE USING A SOLDERING IRON.
Resistors → The resistors in this kit provide current limiting to the LEDs as well as setting up the timer interval across the 555 timers.
LEDs → The five red LEDs are all connected in parallel and the five blue LEDs are also all connected in parallel. They are connected backwards to each other so only one side will light up at a given time depending on current flow.
Count all of your parts and verify everything is in your kit.
Locate the two 68k Ohm Resistors and install them in positions R1 and R2. Bend the legs slightly outward will help hold them in place while you solder.
Locate the two 470 ohm resistors and install them into locations R3 and R4.
Next we will take the two 8 pin sockets, and place them into IC1 and IC2. Be sure that the notch on the sockets match the silk screen on the PCB.
Install the 2.2uF Electrolytic Capacitor at location C1. Be sure that the white strip is aligned with the white strip next to the C1 designation. This component must be installed in the correct orientation to work correctly.
Find the 0.1uF capacitor, and install it into location C2. It does not matter which pin goes in which hole as this is a ceramic capacitor.
Separate the LEDs based on color. The RED LEDs will be installed at locations LED1, LED2, LED3, LED4, and LED5. The BLUE LEDs will be install at locations LED6, LED7, LED8, LED9, and LED10. LEDs must be installed in the correct orientation. The long leg will go into the round pad, and the short leg will go into the square pad.
Solder the Red and Black 9V Battery Wire to the BATTERY location. Be sure that RED goes to the + and BLACK goes to the -. You can install the wire from either side. We prefer installing from the bottom as it is cleaner.
Install both 555 Timers, making sure that the notch on the IC aligns with the notch on the PCB. Push them all the way in until they are seated, you may hear a click to know they are all the way in. Connect the battery to the header, and your kit should now strobe between the Red and Blue LEDs.