Hammer protection circuit
AssigneeXerox Corporation
InventorFereidoon Matin
Life of this patent
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Abstract
A hammer protection circuit automatically disconnects a power supply from a hammer actuating coil in order to inhibit current flow through the coil when such current flow is either greater than a predetermined level or present for greater than a predetermined time period. The circuit comprises charging means coupled to the coil for charging up to a voltage level proportional to the level and duration of the current flow through the coil, comparator means coupled to the charging means for comparing the voltage level with a reference voltage and for generating an output signal when the voltage level bears a predetermined relationship toward the reference voltage, and means coupled to the comparator means and to the power supply and responsive to the output signal for disconnecting the power supply from the coil.
Claims9
A hammer protection circuit for automatically disconnecting a power supply from a hammer actuating coil in order to cut-off current flow through said coil when said current flow is either greater than a predetermined level or present for greater than a predetermined time interval, said circuit comprising:
- charging means coupled to said coil for charging up to a voltage level proportional to the level and duration of said current flow through said coil;
- comparator means coupled to said charging means for comparing said voltage level with a reference voltage and for generating an output signal when said voltage level bears a predetermined relationship toward said reference voltage;
- and
- means coupled to said comparator means and to said power supply and responsive to said output signal for disconnecting said power supply from said coil.
Dependencies are inferred from the claim text.