7656results about How to "Reduce voltage" patented technology

An electronic paper display device, a manufacturing method and a driving method thereof are disclosed. Micro protrusion members are formed at electrodes or at insulating layers. Consequently, the electrophoretic particles are prevented from being securely attached to an upper or the lower structure, and therefore, the quality of pictures is improved, and the contrast ratio of the pictures is increased. The relative sizes and the injection amounts of two kinds of electrophoretic particles are changed such that the relative sizes and the injection amounts of the electrophoretic particles are different from each other. Consequently, the driving voltage is lowered by excessively electrifying the electrophoretic particles of one kind. Protrusions are formed at the corresponding electrode such that a relatively large electric field is distributed around the electrode at which electrophoretic particles are located in the initial stage of voltage application. Consequently, the electrophoretic particles are easily separated from the electrode and moved even at low driving voltage. As such, the voltage level of the driving voltage pulse is lowered. Consequently, it is possible to further increase the response speed of the driving devices and to lower the internal voltage of the devices, thereby reducing the costs related to the driving devices.

A material for an organic electroluminescent device including an imine derivative represented by the following formula (Ia) or (Ib),wherein Y1 to Y4 are independently a carbon atom or a nitrogen atom; R1 to R4 are independently hydrogen, an alkyl group, an aryl group, a heterocycle, a halogen atom, a fluoroalkyl group or a cyano group; and R1 and R2, or R3 and R4 may be bonded together to form a ring.

A method for preventing an excess voltage from appearing at an output of a power over Ethernet controller, the method comprising: sensing that a powered device has been disconnected from a port; enabling a bypass path around a means for unidirectional current flow operatively connected to the port; and disconnecting power to the port responsive to the sensed disconnect, whereby the bypass path enables a discharge path for an output capacitor present across the port. The invention also provides for a circuit having a bypass path around a means for unidirectional current flow, the bypass path being enabled by a control circuit to prevent an excess voltage from appearing at a sensing input of the control circuit. In an exemplary embodiment the bypass path is enabled approximately simultaneously with disconnecting power from the output port.

A snubber circuit and corresponding power converter topology for controlling the voltage across the resonant capacitor at turn on of a control switch so as to suppress a spike at the switch caused by the large current pulse and parasitic inductance of the power converter. The suppression of the spike reduces conduction losses and increases efficiency. According to one embodiment, the snubber circuit in a boost converter topology includes a second winding tapped from the main boost inductor and connected in series with a first diode and a second diode. A resonant capacitor and the second diode are connected in a series combination which is in parallel with the main boost diode. The second winding is connected in series with the first diode and the second diode between the output terminals of the converter. Alternatively, the snubber circuit is used in flyback, buck, and forward converter topologies.

Tunable dielectric materials including an electronically tunable dielectric ceramic and a low loss glass additive are disclosed. The tunable dielectric may comprise a ferroelectric perskovite material such as barium strontium titanate. The glass additive may comprise boron, barium, calcium, lithium, manganese, silicon, zinc and / or aluminum-containing glasses having dielectric losses of less than 0.003 at 2 GHz. The materials may further include other additives such as non-tunable metal oxides and silicates. The low loss glass additive enables the materials to be sintered at relatively low temperatures while providing improved properties such as low microwave losses and high breakdown strengths.