METHOD AND APPARATUS FOR MAGNETIC RECORDING Russian patent published in 1994 - IPC

FIELD: recording acoustic information signals onto moving magnetic record medium. SUBSTANCE: method involves the steps of: applying an AC biasing signal and recording signal to a recording head, shaping an AC biasing control signal and modulating the AC biasing signal by the control one,, additionally shaping a sampling signal which frequency is varied with the aid of the control signal within the range of 40-200 kHz, pulse-width modulating of the information signal the range of 40-200 kHz, pulse-width modulating of the information signal by the obtained sampling signal, combination components in the obtained pulse-width modulated signal being AC biasing current and low-frequency components being a recording signal, shaping a feedback signal for the recording signal. The device for effecting method has an amplifying circuit for receiving the information signal and AC biasing signal shaping unit connected to the recording head. The AC biasing signal shaping unit has a sampling signal generator connected to a pulse-width modulator, a recording signal current feedback being provided in the device. EFFECT: enhanced reliability in controlling AC biasing signal frequency and control signal transmission time reduced. 9 cl, 9 dwg