Abstract: A device for reading servo information from a medium in a buried servo magnetic head system. The device consists of a coil for reading/writing data in the medium and a coil for reading the low-frequency servo signal, both coils being wound around the same core. The servo coil has a greater number of turns than the read/write coil which results in the servo signal having a lower resonance frequency than the read/write signal. By obtaining a separate read/write signal and a servo signal produced from a single core in a single head, physical positional errors are avoided without sacrificing the optimization of the separate signals.

Abstract: A servo protection circuit comprises a sync detector for generating a sync pulse in response to a sync code prerecorded in each sector of a magnetic disk to permit synchronism to be reestablished between the disk and the servo protect pulse at the beginning of each sector. In response to the sync pulse, a servo protect pulse is generated having a duration variable with the interval between successive ones of the sync pulse so that servo protection begins and ends with the beginning and ending points of each prerecorded servocontrol field. The servo protection circuit includes a delay circuit for introducing a shorter delay time of constant duration to the sync pulse to determine the trailing edge of the servo protect pulse and introducing a longer delay time of constant duration to the sync pulse to determine the leading edge of the servo protect pulse.

Abstract: A process for the production of a vinyl polymer containing a tertiary amino group, which comprises subjecting (a-1) a vinyl polymer containing a carboxylic anhydride group obtained by copolymerizing maleic anhydride, itaconic anhydride or mixtures thereof with at least one copolymerizable monomer and (a-2) a compound containing both one primary amino group and one tertiary amino group for each molecule to a ring-opening reaction, and dehydrocyclizing the adduct to form an imide ring containing polymer. A curable resin composition comprising the resulting polymer and a polyepoxy compound as essential ingredients.

Abstract: A process for the production of a vinyl polymer containing a tertiary amino group, which comprises subjecting (a-1) a vinyl polymer containing a carboxylic anhydride group obtained by copolymerizing maleic anhydride, itaconic anhydride or mixtures thereof with at least one copolymerizable monomer and (a-2) a compound containing both one primary amino group and one tertiary amino group for each molecule to a ring-opening reaction, and dehydrocyclizing the adduct to form an imide ring containing polymer. A curable resin composition comprising the resulting polymer and a polyepoxy compound as essential ingredients.

Abstract: A resin composition for powder coating, said composition consisting essentially of(A) 60 to 97% by weight of a polyester resin having an acid value of 15 to 200 mgKOH/g and a softening point of 80.degree. to 150.degree. C., and(B) 3 to 40% by weight of a glycidyl-containing acrylic polymer unmodified or modified with a monobasic acid.

Abstract: An arrester having at least two stacks of non-linear resistors connected in series, an arcing gap device connected to shunt one stack of resistors when the gap means sparks over, and a hermetically sealed housing enclosing the resistor stacks and arcing gap device and filled with sulfur hexafluoride gas having a gauge pressure not less than 2 kg/cm.sup.2. The impedance of the one resistor stack is from about 15% to about 35% of the total impedance of the two resistor stacks when the arcing gap means sparks over, and the rated voltage of the arrester is not less than about 50 KV.

Abstract: PCT No. PCT/JP78/00013 Sec. 371 Date June 28, 1979 Sec. 102(e) Date June 19, 1979 PCT Filed Oct. 26, 1978 PCT Pub. No. W079/00240 PCT Pub. Date May 3, 1979It has previously been known that the poor pigment dispersibility of an acrylic paint is its defect. The present invention provides a modified acrylic copolymer having superior pigment dispersibility and being suitable as a vehicle for acrylic paints. The copolymer is obtained by polymerizing specified proportions of a polyester containing an unsaturated double bond, a dialkylaminoalkyl (meth)acrylate, methyl methacrylate and another polymerizable monomer, and has a weight average molecular weight/number average molecular weight ratio within the range of 3 to 20.

Abstract: In a method for detecting foreign matters present in gas sealed electrical apparatus including a tank at the ground potential and containing an insulating gas and a high voltage live part disposed in the tank, a voltage is applied to the high voltage live part causing generation of ultrasonic waves and the ultrasonic waves propagated through the tank is sensed by a sensing element mounted on the tank.

Abstract: A process for producing a resin dispersion characterized in that an ethylenically unsaturated monomer capable of forming a polymer insoluble in an aqueous medium is polymerized in a solution formed by dissolving in said aqueous medium a water-soluble polymer derived from(1) 10-90% by weight of a hydroxyalkyl (meth-)acrylate expressed by the following general formula ##STR1## wherein R is a hydrogen atom or a methyl group, and l is an integer of 2, 3 or 4,(2) 10-90% by weight of a polyalkyleneglycol mono (meth-)acrylate expressed by the following general formula ##STR2## wherein R is a hydrogen atom or a methyl group, m is an integer of 2 or 3, and n is an integer of 2 to 20, and(3) 0-30% by weight of another ethylenically unsaturated monomer.