Codes and circuits

Phillip G Nelson1

  • 1National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, MD, USA. nelsonp@mail.nih.gov

Summary

Marshall Nirenberg

Related Concept Videos

Circuit Terminology01:14

Circuit Terminology

An electrical network is a system composed of interconnected elements, such as resistors, capacitors, inductors, and voltage or current sources. Unlike a circuit, an electrical network does not necessarily form a closed path. In other words, while all circuits can be considered networks due to their interconnected nature, not every network qualifies as a circuit.
A circuit, on the other hand, is also an interconnected system of electrical elements but must contain one or more closed paths.
First-Order Circuits01:15

First-Order Circuits

First-order electrical circuits, which comprise resistors and a single energy storage element - either a capacitor or an inductor, are fundamental to many electronic systems. These circuits are governed by a first-order differential equation that describes the relationship between input and output signals.
One common example of a first-order circuit is the RC (resistor-capacitor) circuit. These circuits are used in relaxation oscillators such as neon lamp oscillator circuits. When voltage is...
Linear Circuits01:17

Linear Circuits

A linear circuit is characterized by its output having a direct proportionality to its input, adhering to the linearity property, which encompasses the principles of homogeneity (scaling) and additivity. Homogeneity dictates that when the input, also referred to as the excitation, is multiplied by a constant factor, the output, known as the response, is correspondingly scaled by the same constant factor. For instance, if the current is multiplied by a constant 'k,' the voltage likewise...
Electric Circuit Elements01:21

Electric Circuit Elements

Circuit elements are the basic building blocks of an electric circuit. Essentially, an electric circuit is the interconnection of these elements. Within electric circuits, one can find two types of elements: passive and active. Active elements have the ability to generate energy, whereas passive elements do not. Passive elements include components like resistors, capacitors, and inductors, while active elements typically encompass generators, batteries, and operational amplifiers.
The most...
Second-Order Circuits01:17

Second-Order Circuits

Integrating two fundamental energy storage elements in electrical circuits results in second-order circuits, encompassing RLC circuits and circuits with dual capacitors or inductors (RC and RL circuits). Second-order circuits are identified by second-order differential equations that link input and output signals.
Input signals typically originate from voltage or current sources, with the output often representing voltage across the capacitor and/or current through the inductor. For example, in...
Applications of RC Circuits01:22

Applications of RC Circuits

A relaxation oscillator is one of the applications of RC circuits. A neon lamp relaxation oscillator comprises a capacitor, a resistor, a voltage source, and a lamp. The lamp acts like an open circuit, with infinite resistance until the potential difference across the lamp reaches a specific voltage. At that voltage, the lamp acts like a short circuit with zero resistance, and the capacitor discharges through the lamp, thus producing light. Once the capacitor is fully discharged through the...