This Arduino project for beginners uses 24 LEDs to make a Knight Rider display. The LEDs are connected to the Arduino pins using series resistors.
Find the circuit diagram and Arduino code at Starting Electronics website.
An op-amp is used as an oscillator in this LED flasher circuit. This is another circuit that can easily be built on an electronic breadboard by beginners in electronics. Click the above link for the circuit diagram.
This circuit uses a 555 timer IC and produces a fixed frequency audible tone that is played through a loudspeaker. No amplifier is necessary as the 555 puts out a signal of high enough amplitude. The circuit is easy to build for beginners in electronics and can be built on an electronic breadboard. Click the above link to find the circuit diagram.
Basic information on soldering irons for beginners. A soldering iron is necessary when assembling an electronic kit or building a circuit on stripboard.
A soldering iron is often needed even if using an electronic breadboard as some components will need wires or connectors soldered to them in order to plug them into the breadboard.