Editing Magnetic amplifier (section)

{{Short description|A type of parametric amplifier}}
{{Infobox media
| image         = Magnetic Amplifier.jpg
| caption       = A small magnetic amplifier rated at 250 watts and designed to operate on 120 VAC, 60 Hz.  The large center winding is the control winding.
}}

The '''magnetic amplifier''' (colloquially known as a "mag amp") is an [[electromagnetism|electromagnetic]] device for amplifying electrical signals.   The magnetic amplifier was invented early in the 20th century, and was used as an alternative to [[vacuum tube]] amplifiers where robustness and high current capacity were required.   [[World War II]] [[Germany]] perfected this type of amplifier, and it was used in the [[V-2 rocket]].  The magnetic amplifier was most prominent in power control and low-frequency signal applications from 1947 to about 1957, when the [[transistor]] began to supplant it.<ref name=Westman68>{{cite book |first=H.P. |last=Westman |title=Reference Data for Radio Engineers |publisher=H. W. Sams |edition=5th |date=1968 |isbn=9780672206788 |oclc=0672206781 |url=https://books.google.com/books?id=n-iIwgEACAAJ |lccn=43-14665 |chapter=Ch. 14 }}</ref>  The magnetic amplifier has now been largely superseded by the transistor-based amplifier, except in a few safety critical, high-reliability or extremely demanding applications. Combinations of transistor and mag-amp techniques are still used.