Motor drive control circuit to restrict motor temperature rise below an upper limit

A drive control system for controlling a drive motor in response to external command signals, comprising:

• first means including first arithmetic means for executing a first arithmetic routine to obtain numerical values corresponding to amounts of successive intermittent operations of said drive motor responsive to respective ones of said external command signals, and further including a duty control register for storing a sum of the obtained numerical values, said first means subtracting from said sum stored in said duty control register a numerical value corresponding to a non-operation time period during which said drive motor is held at rest between said successive intermittent operations;
• and
• second means for inhibiting the operation of said drive motor responsive to the next command signal, for a length of time corresponding to the current sum of said numerical values after said drive motor has completed each of said intermittent operations, said second means including a second arithmetic means for executing a second arithmetic routine to obtain said length of time of inhibiting said drive motor.

A drive control system for controlling a drive motor to drive a print wheel for a printer having a keyboard, the print wheel having a multiplicity of radially extending arms circumferentially spaced from each other, the arms having at their free ends type elements which are selectively moved into a printing position through rotation of the print wheel upon generation of command signals generated from said keyboard, said drive control system comprising:

• first means for obtaining numerical values corresponding to amounts of successive intermittent angular displacements of said drive motor responsive to respective ones of said command signals, summing the obtained numerical values, and subtracting from a current sum of the numerical values a numerical value corresponding to a non-operation time period during which said drive motor is held at rest between said successive intermittent angular displacements;
• and
• second means for inhibiting the operation of said drive motor responsive to the next command signal, for a length of time corresponding to said current sum after said drive motor has completed each of said intermittent angular displacements.

A printer including a keyboard, a printing head having a type carrier with multiple type elements, a first drive motor responsive to command signals from the keyboard to operate said type carrier to bring said type elements into a printing position, a second drive motor responsive to said command signals to move said printing head along a line of printing, and a drive control system for controlling said first and second drive motors, said drive control system comprising:

• first means for obtaining numerical values corresponding to amounts of successive intermittent displacements of at least one of said first and second drive motors responsive to respective ones of said command signals, summing the obtained numerical values, and subtracting from a current sum of the numerical values a numerical value corresponding to a non-operation time period during which said at least one drive motor is held at rest between said successive intermittent displacements;
• and
• second means for inhibiting the operation of said at least one drive motor responsive to the next command signal, for a length of time corresponding to said current sum after said at least one drive motor has completed each of said intermittent displacements.