Abstract: An oil condition determination system includes a resistance value measurement unit and a determination unit. The resistance value measurement unit applies a measurement voltage between a pair of measurement electrodes in contact with oil to measure a resistance value of the oil. The determination unit determines, when a change tendency of the resistance value of the oil is reversed, that condition of the oil is changed.

Abstract: An oil condition determination system includes a resistance value measurement unit and a determination unit. The resistance value measurement unit applies a measurement voltage between a pair of measurement electrodes in contact with oil to measure a resistance value of the oil. The determination unit determines, when a change tendency of the resistance value of the oil is reversed, that condition of the oil is changed.

Abstract: An oscillator device includes a resonator including a coil and a capacitor connected to the coil in parallel; and an oscillator connected to the resonator. Electric waves are emitted from the coil to at least one receiving antenna of the receiver while the oscillator device changes position and direction over time. The coil has an outer diameter and a total length which is approximately the same as the outer diameter.

Abstract: A high frequency device includes an antenna connector adapted to be connected with an antenna, a board, a conductor layer provided on an upper surface of the board, a filter mounted on the upper surface of the board and connected with the antenna connector, and a high frequency circuit mounted on a lower surface of the board and connected with the filter. The filter includes a case having a hollow shape having an opening which opens downward, and a resonator accommodated in the case. The case has a lower end around the opening. The lower end of the case is joined to the conductor layer. The high frequency device has a small size.

Abstract: An antenna to be embedded in a capsule type medical device. The antenna includes an antenna conductor, and a sheet-like antenna substrate which at least partly electrically contacts with the antenna conductor. The antenna is formed by closely attaching the antenna conductor and the sheet-like antenna substrate.

Abstract: An oscillator device includes a resonator including a coil and a capacitor connected to the coil in parallel; and an oscillator connected to the resonator. Electric waves are emitted from the coil to at least one receiving antenna of the receiver while the oscillator device changes position and direction over time. The coil has an outer diameter and a total length which is approximately the same as the outer diameter.

Abstract: A transmission/reception system includes a transmitter and a receiver. The transmitter includes a voltage converter for generating a voltage according to transmission data, a voltage-controlled oscillator for generating a signal of a frequency corresponding to the voltage generated by the voltage converter under non-feedback control, and a first antenna for emitting the signal generated by the voltage-controlled oscillator.

Abstract: A piezoelectric filter is one not changing in the holding position a resonator in spite of impulse, small in the number of parts, easy to assemble from one direction, small, thin, and stable in characteristic. For example, as shown in FIG. 7, on electrode patterns on a package 10 forming wiring electrode patterns 11, holding protrusions 13 for holding resonators, and partition boards 14 for positioning resonators, a rectangular plate type piezoelectric resonators 12 are adhered with conductive adhesive. The rectangular plate type piezoelectric resonators 12 and the package 10 are adhered and reinforced from above with a vibration absorbing member 15, and wiring is formed from above the resonators by wire bonding 16, thereby wiring resonators in a ladder form. Or, as shown in FIG.

Abstract: A piezoelectric filter is one not changing in the holding position of resonator in spite of impulse, small in the number of parts, easy to assemble from one direction, small, thin, and stable in characteristic. For example, as shown in FIG. 7, on electrode patterns on a package 10 forming wiring electrode patterns 11, holding protrusions 13 for holding resonators, and partition boards 14 for positioning resonators, a rectangular plate type piezoelectric resonators 12 are adhered with conductive adhesive. The rectangular plate type piezoelectric resonators 12 and the package 10 are adhered and reinforced from above with a vibration absorbing member 15, and wiring is formed from above the resonators by a wire bonding 16, thereby wiring resonators in a ladder form. Or, as shown in FIG.

Abstract: A piezoelectric filter is one not changing in the holding position of resonator in spite of impulse, small in the number of parts, easy to assemble from one direction, small, thin, and stable in characteristic. For example, as shown in FIG. 7, on electrode patterns on a package 10 forming wiring electrode patterns 11, holding protrusions 13 for holding resonators, and partition boards 14 for positioning resonators, a rectangular plate type piezoelectric resonators 12 are adhered with conductive adhesive. The rectangular plate type piezoelectric resonators 12 and the package 10 are adhered and reinforced from above with a vibration absorbing member 15, and wiring is formed from above the resonators by a wire bonding 16, thereby wiring resonators in a ladder form. Or, as shown in FIG.

Abstract: In a piezoelectric resonator having a piezoelectric bar formed in a substantial rectangular parallelopiped and electrodes formed on a pair of confronting surfaces of the piezoelectric bar for resonating in the length expander mode, the piezoelectric bar has at least a bevel portion extending the longitudinal direction. In a ladder filter having series and parallel piezoelectric resonators, the series piezoelectric resonator has the bevel portion to shift a frequency of a spurious response to that of the parallel piezoelectric resonator to suppress the spurious response. It is disclosed that a second piezoelectric resonator has a piezoelectric bar formed in a rectangular parallelopiped has a length L, a width W, and a thickness T wherein L>W>T; and electrodes formed on a pair of confronting surfaces defined by L and T. Another ladder filter includes the second piezoelectric resonator as the series resonator to decrease a capacitance between the electrodes to increase an amount of attenuation.