What is a Transformer?

A transformer is a device that transfers electrical energy from one alternating circuit to another.  It is composed of at least two coils of insulated wire mainly copper, wound around a ferromagnetic core, some transformers may have a air-core.  The energy transfer occurs because of mutual induction, caused by magnetic flux around the core.  The coils are inductively coupled to each other when alternating current flows in either coil.  When this happens alternating voltage is induced in the other coil.  The value of this voltage depends on the number of turns in the two coils.  The coil connected to a source of alternating voltage is usually called the primary coil, and the voltage across this coil is the primary voltage.  Voltage induced in the secondary coil may be greater than or less than the  primary  voltage, depending on the ratio of primary to secondary turns.   A transformer is termed a step-up or a step-down transformer by appropriately selecting the ratio of turns, a transformer thus allows an alternating current (AC) voltage to be "stepped up" by making secondary turns greater than the primary.  A transformer is termed a step-down by making the primary turns greater than the secondary.   Since incoming power and outgoing power will always be the same, the following formula applies: P (incoming) = I1V1 = P (outgoing) = I2V2, where I1 and V1 is the primary current and voltage and I2 and V2 is the secondary current and voltage. Notice, I (amperage, or current) in the secondary drops as voltage rises and rises as the voltage drops.  Transformers range in size from a thumbnail-sized inside a stage microphones to huge units weighing hundreds of tons used to interconnect portions of power grids.  All operate with the same basic principles.   Large  Step-Up and Step-Down Transformers  are often specially constructed to stabilize or reduce temperature incurred when resistance in the lines creates heat.   They may be passively cooled through special oil baths, sometimes also having radiating vanes to dissipate heat, or through non-liquid coatings and heat dissipation vanes.   Some applications demand more cooling and will incorporate the use of fans or cooling baths of special gases.  Transformers are essential for high voltage power transmission, which makes long distance transmission economically practical.   Although new technologies have eliminated the need for transformers in some electronic circuits, transformers are still found in nearly all electronic devices designed for household voltages.   The schematic symbol for a transformer is shown below.


There is much more to be learned about transformer as with all the other electronic components mentioned on this site.  More can be learned from reading and experimentation which can be found in, Greg S. Carpenters Book, "Introduction to Basic Electronics Hands-On Mini Course".  For more information on the book, Click Here!

Office DEPOT - Copier Paper and a Lot More

Copy & Print Depot
buying contact lenses online - 123 Lens provides the exact contact lenses prescribed by your eye doctor, in factory sealed vials, at a savings of up to 70% off what you would pay at the retail level.
chicago real estate - Find a new Chicago House to be your home in the sale listings at Metro Chicago Real Estate.

Cash for Electronic Scrap

Best in Travel.

Red Logo 200X50

Final Fantasy XIII 2

GameStop, Inc.