| 摘要 |
A method of accurately emulating any desired tooth/slot format of a desired target wheel from a predetermined tooth/slot arrangement of a rotating actual target wheel used in conjunction with an MR position sensor. The passage of two sequential slots of differing widths or two sequential teeth of differing widths of the actual target wheel determine the rising and falling edge of one tooth of the desired target wheel and define one tooth and one slot of the desired target wheel. The actual target wheel, has, preferably, 2n teeth and 2n slots of two distinct sequential widths whereby the desired target wheel is emulated to have n teeth and n slots. The two MRs of the position sensor are aligned in the circumferential direction of the actual target wheel so as to generate two angularly offset signals (first and second voltages, respectively) from the passage of a single slot of the actual target wheel. The offset signals are input to a signal conditioning circuit. Within the signal conditioning circuit, the two sensor signals (first and second voltages) are differentially amplified to produce a differential signal whereby the width of the slot is used to encode a binary position voltage, high or low. The two distinct sequential slot/tooth widths of the actual target wheel are used to identify a tooth edge of the desired target wheel as rising or falling and, hence, define the teeth and slots of the desired target wheel. Alternatively, the present invention could be implemented with width encoded teeth instead of width encoded slots.
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