Rca Licensing Corporation

Burle Technologies, Inc.

Theodor E Bart

Felix Aschwanden

Peter E Haferl

A MOSFET power switching transistor in a DC-to-DC converter of a television apparatus has a drain electrode that is coupled via a primary winding of a chopper transformer to an input supply voltage. A first signal at a given frequency causes, during normal operation, alternate conduction and nonconduction in the transistor. A second signal is generated that is proportional to the voltage developed across the internal 'on' resistance of the transistor when the transistor is conductive. The second signal is clamped when the MOSFET transistor is nonconductive. The second signal is coupled via a current sensing arrangement to the transistor gate. The second signal prevents the transistor from further conducting when the amplitude of the second signal exceeds a predetermined value that corresponds with a predetermined limiting threshold level of current in the transistor.

Power supply fault protection circuit

A motion detector which compares the video signal from a camera to a camera signal from an earlier scene and produces an alarm signal if an edge of any object has changed its position, but protects against false signals. A phase detector is used to sense movement in only the edges of objects and a vertical coincidence circuit requires object movement in several vertical video lines to prevent false signals from such small items as raindrops. Several adjacent horizontal areas must also show movement in order to activate an alarm.

Growing community of inventors

Kindhausen, Switzerland

Theodor E Bart