| 摘要 |
1,194,464. Magnetic storage arrangements. NETHERLANDS POSTAL & TELECOMMUNICATION SERVICE, DIRECTOR GENERAL OF. 25 July, 1968 [10 Aug., 1967], No. 35558/68. Heading H3B. The flux of a magnetic core K, Fig. 6, having a substantially rectangular hysteresis loop is switched by discharge of a capacitor C through a resistor R1-R10 and a coil L from a saturated level #1, Fig. 2, to a level #3 intermediate the saturation level limits #<SP>1</SP>, #<SP>4</SP>, and is subsequently restored in steps 1-5, Fig. 5, to its initial level #1 by a train of pulses each of the same volt-second content, the extent of flux change #1 to #3 caused by the capacitor discharge being denoted by the number of restoration pulses required. The capacitor is shunted by a Zener diode Z and is charged through a resistor Ra from a D.C. supply +24 v. when relay A is released. Closure of switch S operates relay A and so completes the capacitor discharge path through a resistor R1-R10, each of a different value, selected by a stepping switch contact T. The value of resistance selected determines the extent by which the core flux changes from the saturated level. The change of core flux, #1 to #3, is read out by stepping the switch contact T to the next position so as to connect a pulse generator G to the coil, an output for each generator pulse being applied to a recording device until the core flux is restored to its initial saturated level #<SP>1</SP>. An oscillatory capacitor discharge is obtained as shown in Fig. 3, the positive half-cycle causing the core flux to be driven further into saturation #2, while the negative half-cycle switches the flux to an intermediate level #3. |
