Roy E Orr

US Patent:

50180118, May 21, 1991

Filed:

Sep 30, 1987

Appl. No.:

7/102692

Inventors:

Robert J. Alvord - Elmwood Park IL
Raymond Bambule - Naperville IL
Roy W. Orr - Mundelein IL
Thomas L. Sorensen - Berwyn IL

Assignee:

Zenith Electronics Corporation - Glenview IL

International Classification:

H04N 504

US Classification:

358148

Abstract:

A monostable, that is triggered by either positive or negative polarity horizontal sync pulses, supplies the horizontal deflection system of a monitor. A first transistor of the monostable has its emitter and its base connected through oppositely poled diodes to the horizontal sync input terminal of the monitor. Incoming horizontal sync pulses of either polarity trigger a respective one of the diodes to drive the first transistor into conduction. The time constant of the first transistor is selected to be slightly greater than the duration of the input sync pulses to preclude the monostable triggering on the trailing edge of a sync pulse.