Abstract: The present invention discloses novel aromatic ketone compounds with functional substitution groups at para- or meta positions which can be used as photo-initiators or effective components of photo-initiator mixtures for the photopolymerizations of ethylenically unsaturated systems. The preparation of these compounds is also disclosed.

Abstract: A switching mode power supply (SMPS) includes a transformer having a primary winding, a secondary winding for providing an output voltage, and an auxiliary winding. The SMPS also includes a power switch coupled to the primary winding. A first control circuit is coupled to the secondary winding, and is configured to provide a first electrical signal to the secondary winding when the output voltage of the SMPS is less than a reference voltage during a discontinuous time, whereupon a second electrical signal is induced in the auxiliary winding. A second control circuit is coupled to the auxiliary winding and the power switch. The second control circuit is configured to regulate the output of the SMPS by controlling the power switch in response to a feedback voltage signal from the auxiliary winding, and is further configured to turn on the power switch in response to the second electrical signal.

Abstract: The present invention discloses novel aromatic ketone compounds with functional substiution groups at para- or meta positions which can be used as photo-initiators or effective components of photo-initiator mixtures for the photopolymerizations of ethylenically unsaturated systems. The preparation of these compounds is also disclosed.

Abstract: A switching mode power supply (SMPS) includes a transformer having a primary winding, a secondary winding for providing an output voltage, and an auxiliary winding. The SMPS also includes a power switch coupled to the primary winding. A first control circuit is coupled to the secondary winding, and is configured to provide a first electrical signal to the secondary winding when the output voltage of the SMPS is less than a reference voltage during a discontinuous time, whereupon a second electrical signal is induced in the auxiliary winding. A second control circuit is coupled to the auxiliary winding and the power switch. The second control circuit is configured to regulate the output of the SMPS by controlling the power switch in response to a feedback voltage signal from the auxiliary winding, and is further configured to turn on the power switch in response to the second electrical signal.

Abstract: Circuits and method for sensing a system output voltage change and transmitting an electrical signal to an auxiliary winding on the primary side. In an embodiment, a primary side controller detects the electrical signal and turns a power switch on and off to transfer energy from a primary winding to a secondary winding. A secondary side controller generates a voltage pulse at a terminal of the secondary winding when the system output voltage is below a reference voltage. The secondary side controller includes an input terminal connected to a system output, an output terminal connected to a terminal of the secondary winding, and a ground terminal connected to a ground potential of the system output.

Abstract: Circuits and method for sensing a system output voltage change and transmitting an electrical signal to an auxiliary winding on the primary side. In an embodiment, a primary side controller detects the electrical signal and turns a power switch on and off to transfer energy from a primary winding to a secondary winding. A secondary side controller generates a voltage pulse at a terminal of the secondary winding when the system output voltage is below a reference voltage. The secondary side controller includes an input terminal connected to a system output, an output terminal connected to a terminal of the secondary winding, and a ground terminal connected to a ground potential of the system output.