GB1201939A - Magnetic transducer head - Google Patents

Abstract

1,201,939. Making transducers. IIT RESEARCH INSTITUTE. 30 Oct., 1967, No. 49229/67. Heading B3A. [Also in Division G5] A magnetic transducer comprises semicircular core parts 17, 18 located in recesses in two mating conductive blocks 35, 36 having cavities defining an annular winding space containing a winding 47 linking the core; the gap 12, block interface, and winding space median plane all being coplanar. As shown, channel-section, semicircular alloy C-cores 17, 18 containing lower coercivity laminations are located in recesses 38, 39 in Cu, Al or Ag blocks 35, 36 integral with, or soldered or welded at 143 to mounting blocks 40, 41 of copper, brass or bronze, the blocks containing machined or pressed annular cavities 45, 46 receiving windings 47, 48. A gap spacer and possibly a copper wedge 32 are positioned at the gap 12 and the core halves clamped together by screws 67 within a magnetic casing 60. Prominent portions of the blocks 35, 36 are removed and the remainder ground to a crowned configuration either flush with, or slightly above, the casing. During recording, the winding 47 may be terminated by a resistor while the bias and a video signal are applied to winding 48, or winding 48 may be short-circuited to obtain a low impedance and high resonant frequency. During playback, the windings 47, 48 are either connected in series-opposition at frequencies below the resonant frequency of winding 47 to give greater signal output between the resonant frequencies of the two windings, or in seriesaiding so as to provide bass-boost below the resonant frequency of winding 47. A multi-channel head (Fig. 4, not shown) consisting of four transducers each comprising two pairs of C-core assemblies (89, 90) located in a common (94) or respective blocks, themselves fixed dovetail-fashion into larger blocks, is constructed as above and mounted for lateral shifting to handle eight-track lubricated tapes.