CRT monitor power control unit

Claim 1

In a computer system having a base unit containing a central processing unit, a graphical interface having a graphics port, a plurality of I/O ports and an electrical power supply, and at least one user input peripheral unit in an input circuit to one of said I/O ports and a non-captive CRT monitor in circuit to said graphics port and having an independent electrical power supply, wherein the improvement consists of: a. normally closed electrical switch means in said independent electrical power supply to, and external of, said CRT monitor; b. timing means including clock means to generate a clock signal of counts of predetermined frequency, and counter means to produce a pulsed signal upon receipt of a pre-selected number of clock signal counts also external of said CRT monitor: c. latch means also external of said CRT monitor and in circuit to apply an interrupt signal to said electrical switch means to open said switch means and interrupt said electrical power supply to said monitor, and first circuit means from said counter means to apply said pulsed signal to said latch means and generate said interrupt signal; d. user activity detection means external of said CRT monitor, in said input circuit of said user input peripheral unit to generate an activity signal upon detection of an input signal from said peripheral unit; and e. second circuit means external of said CRT monitor from said user activity detection means to apply said activity signal to reset said counter means and to apply said activity signal to clear said latch means.