John Santiago

When doing circuit analysis, you need to know some essential laws, electrical quantities, relationships, and theorems.Ohm’s law is a key device equation that relates current, voltage, and resistance. Using Kirchhoff’s laws, you can simplify a network of resistors using a single equivalent resistor. You can also do the same type of calculation to obtain the equivalent capacitance and inductance for a network of capacitors or inductors.

Certain electrical quantities, relationships, and electrical units are critical to know when you’re analyzing and characterizing circuit behavior. The following table can help you keep this information straight.

Laplace transform methods can be employed to study circuits in the s-domain. Laplace techniques convert circuits with voltage and current signals that change with time to the s-domain so you can analyze the circuit's action using only algebraic techniques. Connection constraints are those physical laws that cause element voltages and currents to behave in certain ways when the devices are interconnected to form a circuit.

In circuits, inductors resist instantaneous changes in current and store magnetic energy. Inductors are electromagnetic devices that find heavy use in radiofrequency (RF) circuits. They serve as RF “chokes,” blocking high-frequency signals. This application of inductor circuits is called filtering. Electronic filters select or block whichever frequencies the user chooses.

Capacitors store energy for later use. The capacitance is the ratio between the amount of charge stored in the capacitor and the applied voltage. Capacitance is measured in farads (F). Find the equivalent capacitance of parallel capacitors You can reduce capacitors connected in parallel or connected in series to one single capacitor.

When timing is off in your computer, specific events don’t occur in the right order. But if you know the physics and i-v relationships of resistors and capacitors, you can create a circuit that detects pulses; then when a pulse is missing, the circuit can trigger an alarm notifying the user of a timing problem.

Here’s your chance to convert light into electricity using simple operational circuits. You can apply a similar approach to develop instruments that measure other physical variables in the environment, such as temperature and pressure. You use an input transducer to turn a physical variable into an electrical variable.

Circuit analysis is a tricky subject, and it’s easy to make certain mistakes, especially when you’re first starting out. You can reduce your odds of making these common mistakes by reviewing the following list. Failing to label voltage polarities and current directions When you analyze any circuit, the first step is to properly label the voltage polarities and current direction for each device in the circuit.

You might need to know how to build band-stop filters to reject line noise. In your stereo or entertainment system, you have unique sounds coming from your favorite music or movies. Special audio effects, different voices, and diverse instruments are synthesized to form a wide range of frequencies. You select, reject, or boost the bass, treble, and midrange frequencies by using an equalizer consisting of many different filters.