If you've experimented with simple electronics, you'll know that the easiest way to build a circuit is simply to connect components together with short lengths of copper cable. But the more components you have to connect, the harder this becomes. That's why electronics designers usually opt for a more systematic way of arranging components on what's called a circuit board. A basic circuit board is simply a rectangle of plastic with copper connecting tracks on one side and lots of holes drilled through it. You can easily connect components together by poking them through the holes and using the copper to link them together, removing bits of copper as necessary, and adding extra wires to make additional connections. This type of circuit board is often called "breadboard".
Electronic equipment that you buy in stores takes this idea a step further using circuit boards that are made automatically in factories. The exact layout of the circuit is printed chemically onto a plastic board, with all the copper tracks created automatically during the manufacturing process. Components are then simply pushed through pre-drilled holes and fastened into place with a kind of electrically conducting adhesive known as solder. A circuit manufactured in this way is known as a printed circuit board (PCB).
When you sart to get to grips with basic soldering and pcbs you can start to fashion more complex things. I think most enthusiast in the past started with an astable multivibrator to make a police siren DE DA sound using a transistor circuit or more simply a NE555 timer. my favorite places for ideas were the electronic magazines available in my 1970s youth.
Magazines such as Radio Electronics, Practical Wireless and Everyday Electronics but now this is combined and called Everyday Practical Electronics (EPE)
now there are many websites such as:
