Speed and direction sensing circuit
First Claim
1. Apparatus responsive to substantially continuous motion of a part (10) to determine the direction of motion of said part comprising:
- sensor means (14) operatively associated with the part (10) for generating first and second phase shifted signals (A, B);
each of said first and second signals comprising a recurring series of opposite signal levels which occur at a rate dependent upon the speed of part motion relative to the sensor means (14);
decoder means (20) having a pair of inputs (A, B) and a plurality of discrete outputs (S0, S1, S2, S3), said outputs being activated in a sequence dependent upon the signal levels applied to the inputs (A, B);
said inputs (A, B) receiving the first and second signals (A, B) and producing a decoder output sequence which progresses according to the direction of motion of the part (10);
up/down counter means (42,
44) having clock and direction inputs;
and logic means (26, 28, 30, 32, 34, 36, 38,
40) connecting the outputs of the decoder to the inputs of the counter means to clock the counter only after the completion of a full sequence and in a direction determined by the order of said sequence.
1 Assignment
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Accused Products
Abstract
A speed and direction detector for rotating bodies such as gears (10) including a pair of spaced sensors (14) mounted adjacent the gear teeth (12) to develop phase-shifted alternating signal waveforms, and a decoder (20) to develop a sequence of output signal conditions (S0-S3) depending upon the relation between the alternating waveform values. Signal stage memories (26, 28, 30, 32, 34, 36) utilizing flip-flops and gates connect the decoder outputs to an up/down counter (42, 44) which is incremented or decremented according to gear rotation direction only if a complete signal condition sequence occurs.
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Citations
10 Claims
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1. Apparatus responsive to substantially continuous motion of a part (10) to determine the direction of motion of said part comprising:
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sensor means (14) operatively associated with the part (10) for generating first and second phase shifted signals (A, B); each of said first and second signals comprising a recurring series of opposite signal levels which occur at a rate dependent upon the speed of part motion relative to the sensor means (14); decoder means (20) having a pair of inputs (A, B) and a plurality of discrete outputs (S0, S1, S2, S3), said outputs being activated in a sequence dependent upon the signal levels applied to the inputs (A, B); said inputs (A, B) receiving the first and second signals (A, B) and producing a decoder output sequence which progresses according to the direction of motion of the part (10); up/down counter means (42,
44) having clock and direction inputs;and logic means (26, 28, 30, 32, 34, 36, 38,
40) connecting the outputs of the decoder to the inputs of the counter means to clock the counter only after the completion of a full sequence and in a direction determined by the order of said sequence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. In a system of the type which detects dynamic operating conditions as a result of the generation of a complete sequence of discrete signal quantities (S0, S1, S2, S3) representing continuous motion of a part (10) in a given direction, and having means (14, 16, 18, 20) for generating the sequence of signal quantities, the improvement which comprises:
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an up/down counter (42,
44) having a count direction input (U/D) and count increment input (CLK);first logic means (26, 28,
30) connecting one of the signal quantities to the count direction input to condition the counter to increment in a given direction only upon the subsequent occurrence of count increment input; and
second logic means (34, 36, 38,
40) connecting another of the signal quantities to the count increment input;said first and second logic means in combination with said counter being operative to vary the direction of the count according to the order in which said one and another signals occur.
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Specification