Transformers
That Mysterious Black Box Explained:
Greenledge Studios
T h i n k hard, work
soft
One of the essential parts of a power supply, transformers are by nature coils of
wire wound on iron frames. They usually generate at least a small amount of heat in operation, and finding the source of heat in an electronic device is a good way to locate transformers. In typical AC/DC power adapters, the block-shaped (and usually black in North America) object that plugs into an AC wall outlet is the transformer, which is why these black plug-in units get warm or even hot to the touch. The trouble is, heat is not desirable in electronic equipment because it shortens the life of materials and thus equipment.
Heat is one by-product of electronic current flow, and in some cases is unnecessarily generated in transformers by poor design choices. By choosing the number of windings in the primary and secondary coils of a transformer, the ratio of the input and output voltages is determined. If the designer cannot find a transformer which matches his requirements, he may select one with a higher output voltage than is needed. The output of the transformer is often followed by voltage rectification and voltage regulation, by which stage any unneccessary voltage will be dissipated as heat. Transformers are either custom-wound or bought off the shelf. If a transformer is available in the right size as determined by the designer then it may not be necessary to waste power or go to the expense of making a custom winding.
Since not all devices are operating well within safety margins for heat dissipation, it is duly advisable to pay attention to heat factors when stacking equipment. Also, be aware that overheating can occur due to normal heat generation such as that in a computer CPU, especially when overcrowding is involved. In either event, the overheating may be caused by either poor design or by careless installation. Ultimately, paying more for a device which has been designed properly and spending the time to consider the location of the device during installation may be well worth the cost. When we are not the designer, then choosing our manufacturer and thinking about these things during installation are our only recourses. Oh, and don't forget to pray.
Another by-product of electronic current flow is magnetism. Transformers generate strong magnetic fields and thus are capable of erasing sensitive magnetic media such as audio or video tape and computer media. Optical media are not in danger from this, however. The caveat here is to avoid storing or bringing magnetic media near any strong magnetic fields, including transformers, power cords and permanent magnets.