Tdk Corporation

Yokogawa Instrument Corporation

Naoki Chida

Dai Matsuoka

Yuji Terada

Kenji Murakami

Miyuki Yanagida

Katsunari Moriai

Kaname Ueda

Koichi Yamaguchi

Koichi Ishii

Katsuhiko Igarashi

Takeshi Yanata

Izuru Soma

Hisayoshi Saito

A varistorcomprises a varistor element, a pair of external electrodeson one main side of the varistor elementand a resistoron the same main side, wherein the resistoris formed so as to connect the pair of external electrodes. The varistor elementcontains zinc oxide as the main component and Ca oxides, Si oxides and rare earth metal oxides as accessory components, wherein the proportion X of the calcium oxides in terms of calcium atoms is 2-80 atomic percent with respect to 100 mol of the main component and the proportion Y of the silicon oxides in terms of silicon atoms is 1-40 atomic percent with respect to 100 mol of the main component, X/Y satisfying formula (1) below, and the external electrodes and resistor contain oxides other than bismuth oxide and copper oxide1&#x2266;&#x3c;3&#x2003;&#x2003;(1).

Varistor

A chip-type electronic component has: a ceramic element body; a plurality of first and second internal electrodes arranged in the ceramic element body so as to be opposed at least in part to each other; a first external connection conductor to which the plurality of first internal electrodes are connected; a second external connection conductor to which the plurality of second internal electrodes are connected; first and second terminal electrodes; a first internal connection conductor arranged in the ceramic element body and connecting the first external connection conductor and the first terminal electrode; and a second internal connection conductor arranged in the ceramic element body and connecting the second external connection conductor and the second terminal electrode. The number of the first internal connection conductor is set to be smaller than the number of the first internal electrodes and the number of the second internal connection conductor is set to be smaller than the number of the second internal electrodes.

Chip-type electronic component

An object of the present invention is to provide a small surge absorption element that exhibits superior impedance matching even for high-speed signals and a surge absorption circuit. The surge absorption element comprises first and second inductor sections and first and second surge absorption sections. The first inductor section comprises first and second coils and the second inductor section comprises third and fourth coils. By suitably setting the coupling coefficients between the respective coils and the induction coefficients of the first to fourth coils, image impedance with an even frequency characteristic can be implemented over a wide area. Further, because the first to fourth coils have a positive magnetically coupled state with respect to one another, the induction coefficients of the first to fourth coils can be reduced in comparison with a case where the first to fourth coils are not afforded a positive magnetically coupled state.

Surge absorption element and surge absorption circuit

A surge absorber has a first terminal electrode, a second terminal electrode, a third terminal electrode, an inductor portion, a surge absorbing portion, and a resistor portion. The inductor portion has a first internal conductor and a second internal conductor mutually coupled in a polarity-reversed relation. One end of the first internal conductor is connected to the first terminal electrode. One end of the second internal conductor is connected to the second terminal electrode. The other end of the first internal conductor is connected to the other end of the second internal conductor. The surge absorbing portion has a first internal electrode and a second internal electrode. The first internal electrode is connected to the other end of the first internal conductor and to the other end of the second internal conductor. The second internal electrode is connected to the third terminal electrode. The resistor portion has a DC resistance component connected between the first terminal electrode and the second terminal electrode.

Surge absorber

A stimulus values direct reading colorimetric instrument comprising a plurality of photoelectric sensors having different spectral responsivities equal or approximately equal to color matching functions X(.lambda.), Y(.lambda.), and Z(.lambda.); and measuring and display device to measure and display the tri-stimulus values X,Y and Z and the chromaticity of the light to be measured by computing the photoelectric sensor output signals caused by the light, wherein the instrument calculates the stimulus values corresponding to the tri-stimulus values and measures the chomaticity by providing at least one corrective photoelectric sensors so as to maximize their spectral responsivities in the vicinity of the transmission threshold wavelengths of each sensor and taking the sum of the output signals from the sensors and the corrective sensor after multiplying each coefficient assigned to the signals by each output signal, respectively.

Colorimetric instrument

Growing community of inventors

Tokyo, Japan

Naoki Chida