Sandor S Mentler

39886492, Oct 26, 1976

Feb 10, 1975

5/548848

Sandor Mentler - Philadelphia PA

General Electric Company - Philadelphia PA

H01H 4732

3171485R

A signal amplitude monitor and relay driver circuit. The input signal is applied to a plurality of diodes connected in series with a set of normally closed relay contacts and a first resistor. A second resistor is connected in parallel with the series connected diodes through a set of normally open contacts of the relay. A third resistor is connected in parallel with the combination of the first resistor and normally closed contacts. A transistor circuit is connected with its emitter-base circuit responsive to the signal developed across the first resistor. The transistor output drives an amplifier which energizes the relay coil. When the normally closed contacts are closed the input signal must exceed a first predetermined level before the transistor circuit becomes conductive causing the amplifier to energize the relay coil. When the relay operates the first resistor is taken out of the circuit because the normally closed contacts open, and the second resistor is connected in the circuit because the normally open contacts close. Under these conditions the transistor circuit will remain conductive until the input signal falls below a second predetermined level, the second predetermined level being lower than the first predetermined level.

51629828, Nov 10, 1992

May 30, 1991

7/707729

Sandor Mentler - Hamilton Square NJ

General Electric Company - NY

H02M 3335

363 26

A DC-to-AC power inverter includes a transformer with a secondary winding and a center-tapped primary. The center tap is connected to one pole of the DC source, and each end of the primary winding is connected to the other pole of the source by a switch. The switches are controlled in a 50% duty cycle mode, a mode in which both switches are ON simultaneously, and/or a mode in which both switches are periodically OFF simultaneously. The both-ON switch condition short-circuits the transformer, with the result that more current flows through the inductor, which has the effect of boosting transformed voltage above that of the 50% duty cycle mode. The both-OFF mode reduces the inductor current and decreases the transformed voltage. The amount of overlap of the both-ON and both-OFF conditions controls the output voltage. A rectifier arrangement may be coupled to the secondary winding to convert the AC output voltage to DC.