The first thing that you should know when building circuits for electrical devices are the theories in basic electronics. Get to know the various components used in them and how to properly connect them to each other. And study how to make and read schematic diagrams that represents graphically the electrical circuit using images and symbols.

Doing so is important when you like to make a particular device but still confused on some parts of this process. This may be something a bit advance for you like the voltage divider which the output produced is a portion only of its input. Before tackling that, learn first or review the basic theories in electronics to better understand the advance stuffs.

Start with identifying the two types of electricity which are alternating current or AC and direct current or DC. The direction that electrical signals flows in AC is reversing constantly or alternating and the reversal rate is measured in Hertz. The flow in DC though is one direction from power source to ground and commonly found with batteries.

A circuit is closed when electric current is being allowed passage through a path to ground from power source which indicates a functioning device normally. While the open one has broken the path and prevents movement when a machine is turned off. This is done using a switch so you can alternate between them rather than removing its source.

Components creates resistance if current pass through from a positive voltage to a ground and a short circuit happens when these two are connected directly. Avoid this direct connections because they would result in breaking, overheating, explosion or fire. Putting only a switch between them is not enough and other parts are needed for additional resistance.

There are two ways to wire things together which are classified as parallel and series with the latter indicating all components are being wired one after the other. Meanwhile, the latter indicates the parts are being wired next with each other and that makes electricity to pass them simultaneously. Using both ways when building circuits is possible.

Resistors are used to add resistance into circuits and reducing their current flow with ohms used in measuring its different values. They have also wattage ratings and the colored bands surrounding their body indicates their resistance value. You can learn these colored bands or search for graphs which helps calculate their values instead.

Capacitors are components that stores electricity then discharges them when it drops and is measured in Farads with common ones being microfarad, nanofarad and picofarad. The commonly used types of capacitors are ceramic disc and electrolytic. The former being non polarized and the latter polarized requiring one of its leg to be properly connected with the power or ground.

Diodes are polarized components allowing current to pass through one direction and would cause a voltage drop. One of its side is called cathode which connects to power and the other is anode. These are just samples of the basic theories you must learn in making electrical devices.