Types of transformers
In general, transformers are used for two purposes: signal matching and power supplies.
Power Transformers
Power transformers are used to convert from one voltage to another, at significant power levels.
Step-up transformers
A "step-up transformer" allows a device that requires a high voltage power supply to operate from a lower voltage source. The transformer takes in the low voltage at a high current and puts out the high voltage at a low current.
Examples:
* You are a Swiss visiting the U.S.A., and want to operate your 220VAC shaver off of the available 110 VAC.
* The CRT display tube of your computer monitor requires thousands of volts, but must run off of 110 VAC from the wall.
Step-down transformers
A "step-down transformer" allows a device that requires a low voltage power supply to operate from a higher voltage. The transformer takes in the high voltage at a low current and puts out a low voltage at a high current.
Examples:
* Your Mailbu-brand landscape lights run on 12VAC, but you plug them into the 110 VAC line.
* Your doorbell doesn't need batteries. It runs on 110 VAC, converted to 12VAC.
This page from the All Electronics catalog (#103, Winter 2003) shows some step-down transformers.
In many cases, step-down transformers take the form of wall warts.
Isolation transformers
An "isolation transformer" does not raise or lower a voltage; whatever voltage comes in is what goes out. An isolation transformer prevents current from flowing directly from one side to the other. This usually serves as a safety device to prevent electrocution.
Variable auto-transformers
A "variable auto-transformer" (variac) can act like a step-up transformer or step-down transformer. It has a big knob on top that allows you to dial in whatever output voltage you want.
This page from the All Electronics catalog (#103, Winter 2003) shows some variacs.
WARNING: A variable auto-transformer does not provide isolation from line current. For that you need an isolation transformer.
Inverters
An "inverter" takes a DC power source and boosts it up to a higher voltage. The most common type of inverter takes power from an automobile and cranks out 110 VAC to run appliances and power tools. Inverters are also used to operate fluorescent lamps from battery power.
Technically, an inverter isn't a transformer; it contains a transformer (and lots of other stuff).
Signal Transformers
"Signal transformers" also take one thing in and transform it to another thing out. But in this case, the power levels are low, and the transformed thing carries some type of information signal.
In most cases, these transformers are thought of as impedance matching.
2006-06-18 00:42:13
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answer #1
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answered by Jigyasu Prani 6
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Types of Transformers
1.Autotransformers:
Autotransformers are different from traditional transformers because autotransformers share a common winding. On each end of the transformer core is an end terminal for the winding, but there is also a second winding that connects at a key intermediary point, forming a third terminal. The first and second terminals conduct the primary voltage, while the third terminal works alongside either the first or second terminal to provide a secondary form of voltage. The first and second terminals have many matching turns in the winding. Voltage is the same for each turn in the first and second terminal. An adaptable autotransformer is another option for this process. By uncovering part of the second winding and using a sliding brush as the second terminal, the number of turns can be varied, thus altering voltage.
2.Polyphase Transformers:
This type of transformer is commonly associated with three phase electric power, which is a common method of transmitting large amounts of high voltage power, such as the national power grid. In this system, three separate wires carry alternating currents of the same frequency, but they reach their peak at different times, thus resulting in a continuous power flow. Occasionally these “three-phase” systems have a neutral wire, depending on the application. Other times, all three phases can be incorporated into one, multiphase transformer. This would require the unification and connection of magnetic circuits so as to encompass the three-phase transmission. Winding patterns can vary and so can the phases of a polyphase transformer.
3.Leakage Transformer:
Leakage transformers have a loose binding between the primary and secondary winding, which leads to a large increase in the amount of inductance leakage. All currents are kept low with leakage transformers, which helps prevent overload. They are useful in applications such as arc welding and certain high-voltage lamps, as well as in the extremely low-voltage applications found in some children’s toys.
Resonant Transformer:
As a type of leakage transformer, resonant transformers depend on the loose pairing of the primary and secondary winding, and on external capacitors to work in combination with the second winding. They can effectively transmit high voltages, and are useful in recovering data from certain radio wave frequency levels.
Audio Transformer:
Originally found in early telephone systems, audio transformers help isolate potential interference and send one signal through multiple electrical circuits. Modern telephone systems still use audio transformers, but they are also found in audio systems where they transmit analog signals between systems. Because these transformers can serve multiple functions, such as preventing interference, splitting a signal, or combining signals, they are found in numerous applications. Amplifiers, loudspeakers, and microphones all depend on audio transformers in order to properly perform.
Insulating and isolating transformers are identical. These terms are used to describe the isolation of the primary and secondary windings, or insulation between the two.
An isolation transformer is a transformer used to transfer electrical power from a source of alternating current (AC) power to some equipment or device while isolating the powered device from the power source, usually for safety reasons. Isolation transformers provide galvanic isolation and are used to protect against electric shock, to suppress electrical noise in sensitive devices, or to transfer power between two circuits which must not be connected. A transformer sold for isolation is often built with special insulation between primary and secondary, and is specified to withstand a high voltage between windings.
Isolation transformers block transmission of the DC component in signals from one circuit to the other, but allow AC components in signals to pass. Transformers that have a ratio of 1 to 1 between the primary and secondary windings are often used to protect secondary circuits and individuals from electrical shocks. Suitably designed isolation transformers block interference caused by ground loops. Isolation transformers with electrostatic shields are used for power supplies for sensitive equipment such as computers, medical devices, or laboratory instruments.
https://www.electrikals.com/products/r/transformers?cid=695&page=1&pagesize=15
https://www.electrikals.com/products/r/isolation-transformers?cid=681&page=1&pagesize=15
2015-10-27 17:37:28
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answer #2
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answered by shaun 4
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well there are 2 kinds. autobots, and decepticans.
2006-06-11 17:35:05
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answer #3
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answered by Anonymous
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