Browse Prior Art Database

Magnetic Sequence Controller

IP.com Disclosure Number: IPCOM000044117D
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Jackson, T: AUTHOR [+2]

Abstract

A technique is described whereby magnetic material, such as Wiegand wire, used in conjunction with sensing coils and flip-flop circuitry, provides an inexpensive sequence controller. When AC excitation voltage is applied to the Wiegand wire, the core saturates in either direction, producing pulses when the AC voltage is rising and when the AC voltage is falling. When a sense coil is wound over the wire, pulses are able to be detected. The pulse position depends on the field strength of the excitation voltage. The pulse position, as shown in Fig. 1, may be altered by bringing a magnetic field in close proximity to the wire. When this technique is used in conjunction with the flip-flop circuitry, as shown in Fig. 2, a sequence controller is attained.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 97% of the total text.

Page 1 of 2

Magnetic Sequence Controller

A technique is described whereby magnetic material, such as Wiegand wire, used in conjunction with sensing coils and flip-flop circuitry, provides an inexpensive sequence controller. When AC excitation voltage is applied to the Wiegand wire, the core saturates in either direction, producing pulses when the AC voltage is rising and when the AC voltage is falling. When a sense coil is wound over the wire, pulses are able to be detected. The pulse position depends on the field strength of the excitation voltage. The pulse position, as shown in Fig. 1, may be altered by bringing a magnetic field in close proximity to the wire. When this technique is used in conjunction with the flip-flop circuitry, as shown in Fig. 2, a sequence controller is attained. When the AC excitation voltage crosses zero, a sense pulse is detected by zero-crossing detector 10. Flip-flop 11 is set and, in turn, sets flip-flop 12, which, in turn, enables counter 13 to start counting clock pulses 14. When the pulses from a second sense coil are detected, the flip-flops are reset and counter 13 stops counting. Counter 15 is a preset counter representing the number of clock pulses between two consecutive sense coil pulses under normal AC excitation voltage. The count of counter 13 is compared at comparator 16 to counter 15. When counter 13 exceeds counter 15, an output signal and sequence complete signal is sent to the application control logic.

1

Page 2 of 2

2

[This p...