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Joule Thief
A joule thief is a minimalist self-oscillating voltage booster that is small, low-cost, and easy to build, typically used for driving small loads. This circuit is also known by other names such as ''blocking oscillator'', ''joule ringer'', or ''vampire torch''. It can use nearly all of the energy in a single-cell electric battery, even far below the voltage where other circuits consider the battery fully discharged (or "dead"); hence the name, which suggests the notion that the circuit is ''stealing'' energy or "joules" from the source – the term is a pun on "jewel thief". The circuit is a variant of the blocking oscillator that forms an unregulated voltage boost converter. The output voltage is increased at the expense of higher current draw on the input, but the integrated (average) current of the output is lowered and brightness of a luminescence decreased. History Prior art The joule thief is not a new concept. Basically, it adds an LED to the output of a self-os ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joule Thief
A joule thief is a minimalist self-oscillating voltage booster that is small, low-cost, and easy to build, typically used for driving small loads. This circuit is also known by other names such as ''blocking oscillator'', ''joule ringer'', or ''vampire torch''. It can use nearly all of the energy in a single-cell electric battery, even far below the voltage where other circuits consider the battery fully discharged (or "dead"); hence the name, which suggests the notion that the circuit is ''stealing'' energy or "joules" from the source – the term is a pun on "jewel thief". The circuit is a variant of the blocking oscillator that forms an unregulated voltage boost converter. The output voltage is increased at the expense of higher current draw on the input, but the integrated (average) current of the output is lowered and brightness of a luminescence decreased. History Prior art The joule thief is not a new concept. Basically, it adds an LED to the output of a self-os ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Oscillators
An electronic oscillator is an electronic circuit that produces a periodic, oscillating electronic signal, often a sine wave or a square wave or a triangle wave. Oscillators convert direct current (DC) from a power supply to an alternating current (AC) signal. They are widely used in many electronic devices ranging from simplest clock generators to digital instruments (like calculators) and complex computers and peripherals etc. Common examples of signals generated by oscillators include signals broadcast by radio and television transmitters, clock signals that regulate computers and quartz clocks, and the sounds produced by electronic beepers and video games. Oscillators are often characterized by the frequency of their output signal: *A low-frequency oscillator (LFO) is an electronic oscillator that generates a frequency below approximately 20 Hz. This term is typically used in the field of audio synthesizers, to distinguish it from an audio frequency oscillator. *An au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power Conversion
In all fields of electrical engineering, power conversion is the process of converting electric energy from one form to another. A power converter is an electrical or electro-mechanical device for converting electrical energy. A power converter can convert alternating current (AC) into direct current (DC) and vice versa; change the voltage or frequency of the current or do some combination of these. The power converter can be as simple as a transformer or it can be a far more complex system, such as resonant converter. The term can also refer to a class of electrical machinery that is used to convert one frequency of alternating current into another. Power conversion systems often incorporate redundancy and voltage regulation. Power converters are classified based on the type of power conversion they do. One way of classifying power conversion systems is according to whether the input and output are alternating current or direct current. Finally, the task of all power converte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switched-mode Power Supply
A switched-mode power supply (switching-mode power supply, switch-mode power supply, switched power supply, SMPS, or switcher) is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently. Like other power supplies, an SMPS transfers power from a DC or AC source (often mains power, see AC adapter) to DC loads, such as a personal computer, while converting voltage and current characteristics. Unlike a linear power supply, the pass transistor of a switching-mode supply continually switches between low-dissipation, full-on and full-off states, and spends very little time in the high dissipation transitions, which minimizes wasted energy. A hypothetical ideal switched-mode power supply dissipates no power. Voltage regulation is achieved by varying the ratio of on-to-off time (also known as duty cycles). In contrast, a linear power supply regulates the output voltage by continually dissipating power in the pass transistor. The swi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forward Converter
Forward is a relative direction, the opposite of backward. Forward may also refer to: People * Forward (surname) Sports * Forward (association football) * Forward (basketball), including: ** Point forward ** Power forward (basketball) ** Small forward * Forward (ice hockey) ** Power forward (ice hockey) * In rugby football: ** Forwards (rugby league), in rugby league football ** Forwards (rugby union), in rugby union football * Forward Sports, a Pakistan sportswear brand * BK Forward, a Swedish club for association football and bandy Politics * Avante (political party) (Portuguese for ''forward''), a political party in Brazil * Forward (Belgium), a political party in Belgium * Forward (Denmark), a political party in Denmark * Forward (Greenland), a political party in Greenland * Forward Party (United States), a centrist American political party * Kadima (Hebrew for ''forward''), a political party in Israel * La République En Marche! (sometimes translated as ''Forward!''), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flyback Converter
The flyback converter is used in both AC/DC conversion, AC/DC, and DC-DC conversion, DC/DC conversion with galvanic isolation between the input and any outputs. The flyback converter is a buck-boost converter with the inductor split to form a transformer, so that the voltage ratios are multiplied with an additional advantage of isolation. When driving, for example, a plasma globe, plasma lamp or a voltage multiplier, the rectifying diode of the boost converter is left out and the device is called a flyback transformer. Structure and principle The schematic of a flyback converter can be seen in Fig. 1. It is equivalent to that of a buck-boost converter, with the inductor split to form a transformer. Therefore, the operating principle of both converters is very similar: * When the switch is closed (top of Fig. 2), the primary of the transformer is directly connected to the input voltage source. The primary current and magnetic flux in the transformer increases, storing energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blocking Oscillator
A blocking oscillator (sometimes called a pulse oscillator) is a simple configuration of discrete electronic components which can produce a free-running signal, requiring only a resistor, a transformer, and one amplifying element such as a transistor or vacuum tube. The name is derived from the fact that the amplifying element is cut-off or "blocked" for most of the duty cycle, producing periodic pulses on the principle of a relaxation oscillator. The non-sinusoidal output is not suitable for use as a radio-frequency local oscillator, but it can serve as a timing generator, to power lights, LEDs, Elwire, or small neon indicators. If the output is used as an audio signal, the simple tones are also sufficient for applications such as alarms or a Morse code practice device. Some cameras use a blocking oscillator to strobe the flash prior to a shot to reduce the red-eye effect. Due to the circuit's simplicity, it forms the basis for many of the learning projects in commerci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Armstrong Oscillator
The Armstrong oscillator (also known as the Meissner oscillator) is an electronic oscillator circuit which uses an inductor and capacitor to generate an oscillation. It is the earliest oscillator circuit, invented by US engineer Edwin Armstrong in 1912 and independently by Austrian engineer Alexander Meissner in 1913, and was used in the first vacuum tube radio transmitters. It is sometimes called a tickler oscillator because its distinguishing feature is that the feedback signal needed to produce oscillations is magnetically coupled into the tank inductor in the input circuit by a "tickler coil" ''(L2, right)'' in the output circuit. Assuming the coupling is weak but sufficient to sustain oscillation, the oscillation frequency ''f'' is determined primarily by the LC circuit (tank circuit L1 and C in the figure on the right) and is approximately given by :f = \frac \, This circuit was widely used in the regenerative radio receiver, popular until the 1940s. In that applica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schottky Diode
The Schottky diode (named after the German physicist Walter H. Schottky), also known as Schottky barrier diode or hot-carrier diode, is a semiconductor diode formed by the junction of a semiconductor with a metal. It has a low forward voltage drop and a very fast switching action. The cat's-whisker detectors used in the early days of wireless and metal rectifiers used in early power applications can be considered primitive Schottky diodes. When sufficient forward voltage is applied, a current flows in the forward direction. A silicon p–n diode has a typical forward voltage of 600–700 mV, while the Schottky's forward voltage is 150–450 mV. This lower forward voltage requirement allows higher switching speeds and better system efficiency. History Walter H. Schottky (1886–1976) in 1914, discovered an irregularity in the emission of thermions in a vacuum tube, now known as the Schottky effect. Construction A metal–semiconductor junction is formed between a metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regulated Joule Thief Generalization And Cleaning
Regulation is the management of complex systems according to a set of rules and trends. In systems theory, these types of rules exist in various fields of biology and society, but the term has slightly different meanings according to context. For example: * in biology, gene regulation and metabolic regulation allow living organisms to adapt to their environment and maintain homeostasis; * in government, typically regulation means stipulations of the delegated legislation which is drafted by subject-matter experts to enforce primary legislation; * in business, industry self-regulation occurs through self-regulatory organizations and trade associations which allow industries to set and enforce rules with less government involvement; and, * in psychology, self-regulation theory is the study of how individuals regulate their thoughts and behaviors to reach goals. Social Regulation in the social, political, psychological, and economic domains can take many forms: legal restrictions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half-wave Rectifier
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation (converting DC to AC) is performed by an inverter. The process is known as ''rectification'', since it "straightens" the direction of current. Physically, rectifiers take a number of forms, including vacuum tube diodes, wet chemical cells, mercury-arc valves, stacks of copper and selenium oxide plates, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motor-generator sets have been used. Early radio receivers, called crystal radios, used a "cat's whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or "crystal detector". Rectifiers have many uses, but are often found serving as components of DC power supplies and hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
