Buying electronic parts on eBay is not as simple as it seems. Most of the time you get what you ordered, sometimes not. Here is a list of my own survival rules I discovered over the past few years.
Soldering a lot of SMD leds? Never sure what polarity the smd led has? Make this simple SMD LED tester.
Take a look in your used battery box and search for a 9V PP3 battery. Solder any resistor with a value between 470 ohms and 10K onto the battery terminals. Continue reading
Modern rear lights use AA batteries that last very long, but still need to be replaced once in a while. Replacing is simple, but take time.
Here is a simple circuit that lets you use your dynamo of your bicycle to power the rear light. Continue reading
This S88 decoder model railroad block occupancy detector can be used to automate your model railroad with software running on your computer.
Used slow whoop alarms can be recycled into a portable version by adding a switch, a battery and a project box. This portable version is useful duringÂ emergency response training. Persons attending the training can get used to the slow whoop sound and recognizing the alarm when used in real hazard situations.
I am busy testing a modular 7-segment led clock. Each module can contain up to 3 pieces of 7-segment led displays driven by a 74HC595D shift register. Modules can be combined into larger strings.
In the video the modules are driven by an Arduino Nano 3.0 using the SPI interface. Continue reading
This tiny DCC decoder has been made to drive 8 leds. Instead of using a more expensive turnout decoder this may be a nice alternative.
Try making a double led dice with 14 leds driven only by 4 available pins of an Atmel Attiny13a. I did it, and it worked. See the result in this video.