Head - Revision history

Jnc: +cat

2018-12-13T03:32:58Z

+cat

Jnc: LInk to new page

2017-09-30T12:47:54Z

LInk to new page

Jnc: identical to audio tape heads

2017-09-29T21:41:48Z

identical to audio tape heads

Jnc: A kind of OK start

2017-09-29T21:14:53Z

A kind of OK start

New page

A '''head''' is the reading/writing device used to store data on a magnetic medium in devices such as a [[drum]], [[disk]] or [[magnetic tape]]. They were initially created to record audio on magnetic tapes and wires.

The head consists of a roughly toroidal piece of material which is very permeable to magnetic fields. This piece has a small slot cut out of it at one point, the 'gap', which is where the reading and writing happens; and a wire coiled around the body of the toroid.

For writing, when current flows through the wire, a circular magnetic field is created in the toroid; when the field gets to the gap, without the permeable material to contain it, it spreads out somewhat in passing from one face to the other.

The surface coated with magnetic material which is where the recording is to be made is brought up close to the gap, and moved past it; the magnetic field escaping at the gap magnetizes the magnetic coating in one direction or another, depending on the direction of the current through the coil.

For reading, the process is reversed; the recorded material is brought close to the gap, and moved past it; the magnetized regions of material on the surface create a very small field in the toroid, and thus very small currents in the coil, which can be amplified and detected.

← Older revision		Revision as of 03:32, 13 December 2018
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	For reading, the process is reversed; the recorded material is brought close to the gap, and moved past it; the magnetized regions of material on the surface create a very small field in the toroid, and thus very small currents in the coil, which can be amplified and detected.		For reading, the process is reversed; the recorded material is brought close to the gap, and moved past it; the magnetized regions of material on the surface create a very small field in the toroid, and thus very small currents in the coil, which can be amplified and detected.
		+
		+	[[Category: Device Basics]]

← Older revision		Revision as of 12:47, 30 September 2017
Line 1:		Line 1:
−	A '''head''' is the reading/writing device used to store data on a magnetic medium in devices such as a [[drum]], [[disk]] or [[magnetic tape]]. They are identical in basic concept to the head on a magnetic tape recorder, and were initially created to record audio on magnetic tapes and wires.	+	A '''head''' is the reading/writing device used to store data on a [[magnetic storage\|magnetic medium]] in devices such as a [[drum]], [[disk]] or [[magnetic tape]]. They are identical in basic concept to the head on a magnetic tape recorder, and were initially created to record audio on magnetic tapes and wires.

	The head consists of a roughly toroidal piece of material which is very permeable to magnetic fields. This piece has a small slot cut out of it at one point, the 'gap', which is where the reading and writing happens; and a wire coiled around the body of the toroid.		The head consists of a roughly toroidal piece of material which is very permeable to magnetic fields. This piece has a small slot cut out of it at one point, the 'gap', which is where the reading and writing happens; and a wire coiled around the body of the toroid.

← Older revision		Revision as of 21:41, 29 September 2017
Line 1:		Line 1:
−	A '''head''' is the reading/writing device used to store data on a magnetic medium in devices such as a [[drum]], [[disk]] or [[magnetic tape]]. They were initially created to record audio on magnetic tapes and wires.	+	A '''head''' is the reading/writing device used to store data on a magnetic medium in devices such as a [[drum]], [[disk]] or [[magnetic tape]]. They are identical in basic concept to the head on a magnetic tape recorder, and were initially created to record audio on magnetic tapes and wires.

	The head consists of a roughly toroidal piece of material which is very permeable to magnetic fields. This piece has a small slot cut out of it at one point, the 'gap', which is where the reading and writing happens; and a wire coiled around the body of the toroid.		The head consists of a roughly toroidal piece of material which is very permeable to magnetic fields. This piece has a small slot cut out of it at one point, the 'gap', which is where the reading and writing happens; and a wire coiled around the body of the toroid.