Noise blanker circuit for use with electronic ignition systems or the like
AssigneeMotorola, Inc.
InventorJames J. LoCascio
Life of this patent
Estimating the term…
Abstract
A circuit suitable to be utilized in an electronic ignition system or the like which receives periodic signal information and which is caused to ignore this information during a portion of each period a predetermined time interval after initiation of each period. The circuit comprises a blanking circuit which is responsive to control signals generated from the input signal information at the predetermined time interval after initiation thereof to produce a blanking signal the duration of which last during the portion of the period and a coincidence gate that is inhibited by the blanking signal but enabled during the remaining portion of each period to pass the signal information between an input and output thereof.
Claims12
A circuit having an input and an output which is responsive to periodic input signals applied to the input for transferring the same to the output at which is connected load circuit means, the circuit being made non-responsive to changes in the input signals which can occur during a portion of each period of each individual input signal a predetermined time interval after initiation of each periodic input signal due to noise transients being coupled onto each periodic input signal, comprising:
- blanking circuit means responsive to control signals generated in response to each periodic input signal for producing a blanking signal at an output thereof during the portion of each period;
- and
- coincidence circuit means having an input and output, said input being coupled both to said output of said blanking circuit means and the input of the circuit, said output being coupled to the output of the circuit, said coincidence circuit means transferring the periodic input signals between said input and output except during the portion of each period when said coincidence circuit means is inhibited by said blanking signal.
In an ignition system responsive to periodic timing signal information generated in timed relationship to an engine rpm for producing dwell current a predetermined time interval after initiation of each timing signal information period to an ignition coil, a circuit for causing the ignition system to ignore the timing signal input information for a predetermined portion of each period occurring after the predetermined time interval when the dwell current is initiated, comprising:
- a blanking circuit responsive to the dwell current being produced for producing a blanking signal at an output the duration of which lasts for said predetermined portion of each period;
- and
- a coincidence circuit having an input coupled to said output of said blanking circuit and receiving said timing signal information and an output, said coincidence circuit being inhibited by said blanking signal whereby the timing signal information is not transferred to the output thereof.
Dependencies are inferred from the claim text.