12.
    发明专利
    未知

    公开(公告)号:DE69310277D1

    公开(公告)日:1997-06-05

    申请号:DE69310277

    申请日:1993-06-30

    Applicant: IBM

    Abstract: An elapsed time recording device includes a counter (130) for incrementally advancing a count value from an initial value towards and beyond a threshold in response to successive clock pulses of a clock signal. Control logic (140) enables the counter (130) to incrementally advance the count value in response to a first input (pin 3) and a second input (pin 1) being at or near a first voltage level, and holds the count value in response to the first input (pin 3) being at or near a second voltage level and the second input (pin 1) being at or near the first voltage level. Setting logic (210) sets the count value to a value beyond the threshold in response to the first input (pin 3) and the second input (pin 1) being at or near the second voltage level when the count value is between the initial value and the threshold. Because the device consists essentially of electronic circuit elements, it can be implemented in the form of an application specific integrated circuit package suitable for high volume manufacture at relatively low cost. The device is therefore favourable for use in mass produced electrical appliances. Because the count value is immediately advanced beyond the threshold in response to removal of the second input voltage, advance of the count value towards the threshold cannot be prevented or delayed by tampering with pin connections of the device.

    14.
    发明专利
    未知

    公开(公告)号:DE69015438T2

    公开(公告)日:1995-07-13

    申请号:DE69015438

    申请日:1990-05-14

    Applicant: IBM

    Abstract: A CRT heater circuit for a CRT display is described, the circuit comprising control means (4) for dynamically varying a voltage (Vh) across the cathode heater in response to variations in the beam current density (I) within the CRT. In this way the optimum voltage across the heater coils is maintained, thus preventing "cathode stripping" at times of peak beam currents, and optimising the CRT's working lifetime.

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