This is my first electronics kit from Velleman: a pair of flashing red LEDs. Wired to each LED is its own potentiometer that I can use to control the flash time of the lights. The slot at the top of the potentiometer is tiny so I have to use a precision flat head screwdriver to operate it (clockwise shortens the flash time, counter-clockwise lengthens it).
The unit itself is about 1.25" square and fits 13 components. These parts consist of four resistors, two transistors, two poteniometers, two red LEDs, two electrolytic capacitors and a 9-volt battery clip.
This was my first go at soldering but I am very pleased with the results. First of all, nothing melted, blew up in my face or otherwise malfunctioned. Also, there were no shorted connections or reversed polarities. For future kits, I will work harder on covering the copper pads completely and avoiding those big unnecessary blobs of solder I found on some of the joints.
I read on the Velleman product page that this kit is good for model construction. Most likely they are used in model railroad settings, for example some kind of blinking crossing guard lights. There must be some way to use wires to light the LED bulb while they're not fastened to the circuit board, allowing more flexibility for light positioning.
Finally, I'm trying to think of a way to modify this circuit. The first thing to come to mind is changing the color of the LEDs bulbs will probably require a change in resistor values as well.
Here's some video of the Mk102 in action!
