GB1050490A - - Google Patents

Abstract

1,050,490. Projectile fuzes. J. PETERS. Dec. 18, 1962 [Dec. 23, 1961], No. 47719/62. Heading F3A. A magnetic proximity fuze which responds to changes in the magnetic field resulting from the superimposition of the magnetic field due to ferromagnetic components of a target on the earth's magnetic field comprises three coils perpendicular to one another, the voltages e x , e y , e z induced in which as a missile containing the fuze approaches the target being fed to amplifiers 25, 26, 27 and then to multipliers 45, 46, 47 where each amplified signal is multiplied by its time integral from integrators 35, 36, 37, the outputs from the multipliers being fed to a common summator 30 which is followed by a further summator 34 in which the time integral from an integrator 31 is added to the output of summator 30 to produce a voltage at the output 40 proportional to |M|<SP>2</SP>+b. d/dt | M |<SP>2</SP>, where " M " is the change of field intensity and "b" a coefficient introduced by a stage 33 in parallel with the integrator 31. Output 40 leads to an electronic switch in which a desired threshold value for the ignition voltage can be adjusted. This switch, which is not absolutely necessary, is followed by the actual fuze. The voltage at the output 40 follows curve 3 (Fig. 6) and is the sum of curve 1, which shows the square of the modulus of the change of field intensity, and curve 2,which gives the differential coefficient with respect to time of this modulus. By suitably choosing coefficient " b " and release threshold 4, the release pulse which causes the ignition of the explosive charge can be advanced to time "t 1 " so that the actual ignition will occur only at time "t 2 " due to the ignition delay, while the nearest approach to the target is reached at time "t 3 " when curve 1 has its peak.