Nihon Dempa Kogyo Co., Ltd.

Manabu Ito

Takeshi Uchida

Hiroyuki Mitome

Takeo Oita

Minoru Fukuda

Tetuo Kudo

Hiroshi Kato

Tomotaka Kuroda

Kenichi Sugawara

Minoru Fukudu

A crystal unit and a thermistor with negative resistance-temperature characteristics are housed in a thermostatic oven heated by a heater. A transistor driving the heater is controlled by an output of a differential amplifier, the thermistor is placed between a power supply voltage and an inverting input of the amplifier, and a first resistor used to adjust the temperature of a zero temperature coefficient point of the crystal unit is installed between the inverting input and a ground point. A second resistor is installed between the power supply voltage and a non-inverting input of the amplifier and a third resistor is installed between the non-inverting input and ground point. One of the second and third resistors is a resistor assembly made up of a plurality of resistance elements and one of these resistance elements is provided with positive resistance-temperature characteristics and adapted to detect ambient temperature.

Oven-controlled crystal oscillator

The present invention relates to an oven controlled crystal oscillator that can obtain stable oscillation frequency by reducing a temperature change in an oscillation element. The oven controlled crystal oscillator comprises; a heat-conducting plate mounted on one surface of a circuit board, a crystal resonator mounted on a surface of the heat-conducting plate opposite to the surface of the circuit board, an oscillation element constituting an oscillation circuit together with the crystal resonator, and a thermistor that detects temperature of the crystal resonator, a heating resistance which heats the crystal resonator, and a temperature control element including at least a power transistor, to constitute a temperature control circuit together with the thermistor and the heating resistance. In the oven controlled crystal oscillator, two or more open areas communicating with the heat-conducting plate at least in the thickness direction thereof are formed on the periphery of the heat-conducting plate at positions point-symmetric with respect to the crystal resonator, and one or more of each of the power transistor and the heating resistance are arranged in the same number in all of the open areas.

Oven controlled crystal oscillator

A temperature controlled oscillator is provided with a circuit substrate having a crystal resonator, an oscillating circuit, and a temperature control circuit, arranged on one or both principal surfaces, and a container main body that accommodates the circuit substrate and has mount terminals on an outer bottom surface thereof. The temperature control circuit includes at least a first temperature sensor that detects an operating temperature of the crystal resonator, a second temperature sensor that detects a surrounding temperature of the container main body, and a heating resistor that applies heat to the crystal resonator, and lead wires extend from the circuit substrate and are connected electrically to the mount terminals. An insulation groove that passes through the circuit substrate in a thickness direction is formed between: a first lead wire closest to the second temperature sensor, and the second temperature sensor; and the heating resistor.

Temperature controlled crystal oscillator

A crystal oscillator for surface mounting comprising: a case main body including concave portions on both principal surfaces; a crystal element hermetically encapsulated in one concave portion; an IC chip housed in the other concave portion; mounting terminals provided on four corner portions of an opening end face of the other concave portion; and a protrusion serving as identifying marks along a direction of sides of the case main body and provided in some of the mounting terminals. The mounting terminals, to which the protrusions are provided, are provided on both corner portions on one end side of the case main body. The protrusions extend in a same direction from the mounting terminals at an inner or outer circumference side of the opening end face. The mounting terminals including the protrusions are symmetric with respect to a center line between both corner portions on the one end side.

Crystal oscillator for surface mounting

A constant-temperature type crystal oscillator includes: a crystal unit including a case main body, in which two crystal terminals and two dummy terminals are provided on an outer bottom face thereof, and a crystal element housed in the case main body; an oscillator output circuit including an oscillating stage and a buffering stage; a temperature control circuit for keeping an operational temperature of the crystal unit; and a circuit substrate, on which circuit elements of the crystal unit, the oscillator output circuit and the temperature control circuit are installed. The temperature control circuit includes: heating chip resistors; a power transistor; and a temperature sensing element. Each of the dummy terminals is connected to a respective one of circuit terminals on the circuit substrate. At least one of the circuit terminals is connected to an electrically-conducting path, to which one terminal of the heating chip resistors is electrically connected, on the circuit substrate.

Constant-temperature type crystal oscillator

Provided is a control circuit for a thermostatic oven in an oven controlled crystal oscillator, which is capable of further improving stability of an oscillation frequency. A control circuit in which a thermistor whose resistance value changes according to a temperature outputs a signal according to the ambient temperature of the thermostatic oven inside the oscillator, an operational amplifier outputs a signal according to a difference between the output of the thermistor and a reference signal, a power transistor amplifies the output of the operational amplifier, and a heater generates heat based on a collector voltage of the power transistor, is provided with a temperature sensor circuit having a transistor with a base to which the output of the operational amplifier is input. The control circuit outputs a collector voltage of the transistor as an internal temperature signal which changes according to a temperature inside the oscillator.

Control circuit for thermostatic oven in oven controlled crystal oscillator

A constant-temperature type crystal oscillator includes: a crystal unit; an oscillator output circuit; a temperature control circuit; and a circuit substrate, on which circuit elements are installed. A principal surface of the crystal unit is installed so as to face one side board plane of the circuit substrate with interposing a first heat conducting resin, and the heating resistors are installed to be thermally coupled to the crystal unit via a second heat conducting resin. The principal surface of the crystal unit adheres to the one side board plane of the circuit substrate with interposing the first heat conducting resin. The heating resistors are installed on the one side board plane of the circuit substrate so as to sandwich the lead wires including a portion between the pair of lead wires of the crystal unit, and the heating resistors surround an outer circumference of the crystal unit.

The present invention relates to a two-level mounting board in which a second substrate is supported horizontally by a metal pin above a first substrate having a mounting electrode on an outer base surface, the free, lower end of the metal pin is inserted in a hole provided in the surface of the first substrate, and the metal pin is affixed by solder to an annular electrode land provided on the surface of the first substrate to form an outer periphery of the hole, wherein part of the ring of the annular electrode land is cut away to open the same. This provides a two-level mounting board in which metal pins can be connected reliably to the first substrate to support the second substrate horizontally, and a crystal oscillator using the same.

Two-level mounting board and crystal oscillator using the same

A lead wire led-out type crystal oscillator of constant temperature type for high stability is disclosed, which includes a heat supply body that supplies heat to a crystal resonator from which a plurality of lead wires are led out, to maintain the temperature constant. The heat supply body includes a heat conducting plate which has through-holes for the lead wires and is mounted on the circuit board, and which faces, and is directly thermally joined to, the crystal resonator and a chip resistor for heating which is mounted on the circuit board adjacent to the heat conducting plate, and is thermally joined to the heat conducting plate.

Constant temperature type crystal oscillator

A constant temperature oscillator includes a crystal oscillator that is provided upright on a circuit board, an oscillation element arranged on the circuit board and configuring an oscillation circuit in conjunction with the crystal oscillator, and a temperature control element including a heating chip resistance and a thermistor, arranged on the circuit board, and configuring a temperature control circuit that keeps an operating temperature of the crystal oscillator constant, and which is provided with a heat transfer plate between the heating chip resistance and the bottom face of the oscillator container, wherein, the heat transfer plate has a notch into which the heating chip resistance is fitted, and a heat sink lies between the heat transfer plate and the heating chip resistance and closely contacts with them.

Constant temperature type crystal oscillator for high stability

To provide a highly stable crystal oscillator having increased thermal efficiency. The highly stable crystal oscillator comprises; a thermostat mainframe which maintains the temperature of a crystal resonator including a resonator container for sealing a crystal piece constant, an oscillating element which constitutes an oscillation circuit together with said crystal resonator, a temperature control element which controls the temperature inside of said thermostat mainframe, and a circuit board mounted with said thermostat mainframe, said oscillating element, and said temperature control element. The construction is such that a heat generating chip resistor and a highly heat sensitive element having a higher temperature dependency, among said oscillating element and said temperature control element, are arranged on one principal plane of said circuit board, and said heat generating chip resistor, said highly heat sensitive element, and said thermostat mainframe are directly heat bonded by a thermo-conductive material.

Growing community of inventors

Saitama, Japan

Manabu Ito