A batteryless radio is a radio receiver which does not require the use of a battery to provide it with electrical power.
Originally this referred to units which could be used directly by AC mains supply (mains radio); it can also refer to units which do not require a power source at all, except for the power that they receive from an ambient radio source, such as radio waves.
Most radios used vacuum tube batteries until the mid to late 1920s. [1] The line-operated vacuum tube receiver was invented in 1925 by Edward S. Rogers, Sr. The unit operated with five Rogers AC vacuum tubes and the Rogers Battery-Eliminator Power Unit (power supply). This unit was later marketed for $120 [2] as "Type 120". He established the Toronto station CFRB (an abbreviation of Canada's First Rogers Batteryless) to promote sales of the product. Batteryless radios were not introduced into the United States until May 1926 and then into Europe in 1927, [3] and the industry did not widely produce batteryless radios until RCA's AC tube in late 1927. [1]
Crystal radio receivers are a very simple kind of batteryless radio receiver. They do not need a battery or power source, except for the power that they receive from radio waves using their long outdoor wire antenna. Sharp Electronics' first electrical product was a batteryless crystal radio introduced in 1925. It was Japan's first—and sold extremely well.
Thermoelectricity was widely used in the remote parts of the Soviet Union from the 1920s to power radios. The equipment comprised some bi-metal rods (thermocouples), one end of which could be inserted into the fireplace to get hot with the other end left out in the cold.
After the Second World War, kerosene radios were made in Moscow for use in rural areas. These all-wave radios were powered by the kerosene lamp hanging above them. A group of thermocouples was heated internally to 300 °C (572 °F) by the flame. Fins cooled the outside to about 30 °C (86 °F). The temperature differential generated enough current to operate the low-drain receiver. [4]
Foot-operated radio or pedal radio was once used in Australia. Other ways of achieving the same function are clockwork radio, hand crank radio and solar radio, especially for the Royal Flying Doctor Service and School of the Air. [5] [ citation needed ]
As part of an energy harvesting electronics system, some batteryless radios render electricity to storage by means of storage capacitors. In this batteryless type of radio, the storage capacitors cache the electricity as static on layers of dielectric instead of chemical changes, providing energy like batteries do but 'batteryless'. This can be quite effective. Storage capacitors recharge millions of times, they are relatively cheap, somewhat insensitive to temperature, and they never need replacing—which is why they are usually soldered on. As part of an energy autarkic or energy harvesting batteryless radio, therefore, storage capacitors are an integral part, storing electricity like battery does for lean energy periods, but in a 'batteryless' way which is more sustainable. About 15 billion batteries are consumed every year worldwide.
A carrier-powered radio is a batteryless radio which "leeches" its power from the incoming electromagnetic wave. A simple circuit (very similar to a crystal set) rectifies the incoming signal and this DC current is then used to power a small transistor amplifier. Typically a strong local station is tuned in to provide power, leaving the listener free to listen to weaker and more distant stations.
A vacuum tube, electron tube, valve, or tube is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
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.
A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As a result, power supplies are sometimes referred to as electric power converters. Some power supplies are separate standalone pieces of equipment, while others are built into the load appliances that they power. Examples of the latter include power supplies found in desktop computers and consumer electronics devices. Other functions that power supplies may perform include limiting the current drawn by the load to safe levels, shutting off the current in the event of an electrical fault, power conditioning to prevent electronic noise or voltage surges on the input from reaching the load, power-factor correction, and storing energy so it can continue to power the load in the event of a temporary interruption in the source power.
A power inverter, inverter, or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the opposite of rectifiers which were originally large electromechanical devices converting AC to DC.
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The antenna intercepts radio waves and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation.
A DC-to-DC converter is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. It is a type of electric power converter. Power levels range from very low to very high.
An AC adapter or AC/DC adapter is a type of external power supply, often enclosed in a case similar to an AC plug. AC adapters deliver electric power to devices that lack internal components to draw voltage and power from mains power themselves. The internal circuitry of an external power supply is often very similar to the design that would be used for a built-in or internal supply.
The term All American Five is a colloquial name for mass-produced, superheterodyne radio receivers that used five vacuum tubes in their design. These radio sets were designed to receive amplitude modulation (AM) broadcasts in the medium wave band, and were manufactured in the United States from the mid-1930s until the early 1960s. By eliminating a power transformer, cost of the units was kept low; the same principle was later applied to television receivers. Variations in the design for lower cost, shortwave bands, better performance or special power supplies existed, although many sets used an identical set of vacuum tubes.
Energy harvesting (EH) – also known as power harvesting,energy scavenging, or ambient power – is the process by which energy is derived from external sources, then stored for use by small, wireless autonomous devices, like those used in wearable electronics, condition monitoring, and wireless sensor networks.
An atomic battery, nuclear battery, radioisotope battery or radioisotope generator uses energy from the decay of a radioactive isotope to generate electricity. Like a nuclear reactor, it generates electricity from nuclear energy, but it differs by not using a chain reaction. Although commonly called batteries, atomic batteries are technically not electrochemical and cannot be charged or recharged. Although they are very costly, they have extremely long lives and high energy density, so they are typically used as power sources for equipment that must operate unattended for long periods, such as spacecraft, pacemakers, underwater systems, and automated scientific stations in remote parts of the world.
An electronic component is any basic discrete electronic device or physical entity part of an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components and elements. A datasheet for an electronic component is a technical document that provides detailed information about the component's specifications, characteristics, and performance. Discrete circuits are made of individual electronic components that only perform one function each as packaged, which are known as discrete components, although strictly the term discrete component refers to such a component with semiconductor material such as individual transistors.
A mechanically powered flashlight is a flashlight that is powered by electricity generated by the muscle power of the user, so it does not need replacement of batteries, or recharging from an electrical source. There are several types which use different operating mechanisms. They use different motions to generate the required power; such as squeezing a handle, winding a crank, or shaking the flashlight itself. These flashlights can also be distinguished by the technique used to store the energy: a spring, a flywheel, a battery or a capacitor.
This is an alphabetical list of articles pertaining specifically to electrical and electronics engineering. For a thematic list, please see List of electrical engineering topics. For a broad overview of engineering, see List of engineering topics. For biographies, see List of engineers.
An antique radio is a radio receiving set that is collectible because of its age and rarity.
Rogers Vacuum Tube Company was founded as the Standard Radio Manufacturing Corporation in 1925 by Edward Rogers (1900–1939) to sell Rogers "Batteryless" radios using vacuum tube technology. It was later renamed Rogers Majestic Corporation Limited when Rogers merged his company with Majestic Corporation of Chicago in 1928. The new company controlled Rogers Radio Tube Company and Rogers Batteryless Radio Company. Joseph Elsworth Rogers (1898–1960), brother of Edward Rogers, was an important member of the company and served as vice-president until 1939, and then as head from 1939 to 1960.
A thermoelectric generator (TEG), also called a Seebeck generator, is a solid state device that converts heat directly into electrical energy through a phenomenon called the Seebeck effect. Thermoelectric generators function like heat engines, but are less bulky and have no moving parts. However, TEGs are typically more expensive and less efficient. When the same principle is used in reverse to create a heat gradient from an electric current, it is called a thermoelectric cooler.
Human power is the rate of work or energy that is produced from the human body. It can also refer to the power of a human. Power comes primarily from muscles, but body heat is also used to do work like warming shelters, food, or other humans.
An AC/DC receiver design is a style of power supply of vacuum tube radio or television receivers that eliminated the bulky and expensive mains transformer. A side-effect of the design was that the receiver could in principle operate from a DC supply as well as an AC supply. Consequently, they were known as "AC/DC receivers".
The following outline is provided as an overview of and topical guide to electronics:
This glossary of electrical and electronics engineering is a list of definitions of terms and concepts related specifically to electrical engineering and electronics engineering. For terms related to engineering in general, see Glossary of engineering.
