Adjustable Temperature Controller For Heating Elements

There are a lot of different products that use heating elements. Unfortunately, many of them are not adjustable. For instance, most soldering irons are either on or off. It would be much more useful if you were able to change the temperature of the iron. This would allow you to use the soldering iron for lower temperature applications.

So I designed a simple control circuit that will let you adjust the output of a heating element.

For step by step instructions on how to build this project, check out the instructions:
http://www.instructables.com/id/Adjustable-Temperature-Controller-For-Heating-Elem/

Designing Circuit Board Layouts with Photoshop

The last step in building a new electronics project is to solder all the components onto a circuit board. You can use something as simple as a perf board or you can go all out and etch your own custom circuit board. Whatever you use, you need to figure out how the parts will be arranged on the board.

There are a number of programs that you can download to help you design a circuit board layout (examples: 123D, EAGLE Light and PCB Artist). But you can also use everyday programs such as photo editors that you might already have on your computer. So today I am going to show you a simple way that you can use programs like Photoshop to design a circuit board layout.

For step by step instructions on how to complete this project, check out the Instructable:
http://www.instructables.com/id/Design-Circuit-Boards-Using-Photoshop/

Automatic Race Timer

Racing is a lot of fun. But if you want to compare the results of multiple races, you need be able to accurately record the finishing times of each one. To do this, I designed a timer circuit that will automatically record the finishing times.

Two light sensors are mounted on a track. The first one is positioned just in front of the starting line. The second is located at the finish line. When the car crosses the first sensor, it starts the timer. Then when the car crosses the second sensor, it stops the timer. This lets you automatically record the finishing time of each car.

The system that I built is tailored to toy car races (such as pinewood derby or CO2 Dragsters), but it can easily be adapted for other kinds of races.

For step by step instructions on how to build this project, check out the Instructable:
http://www.instructables.com/id/Automatic-Race-Timer/