COSEL Co.

Toyama-shi, Japan

COSEL Co.

Toyama-shi, Japan
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Patent
Cosel Co. | Date: 2017-08-09

[Problem] As for an insulation-type converter circuit, to achieve soft switching operation to allow high efficiency, low noise, and low cost. [Solution] A switching power supply apparatus is configured of, as a primary-side circuit, a synchronous rectification step-up/down chopper circuit including a main switching element 14, a commutation element 16, a choke coil 18, and a buffer capacitor 20. As a secondary-side circuit, to a secondary winding 22 provided to the choke coil 18, a series circuit including a rectifying element 26 and an output capacitor 24 is connected. An inductance of the choke coil 18 is set to have a predetermined value so that a choke coil current IL flowing through the choke coil 18 flows in both of a positive direction and a negative direction across zero in one cycle of switching when an output current is equal to or smaller than a maximum output current. A switching control circuit 30 performs control of complementarily turning the main switching element 14 and the commutation element 16 ON/OFF in a switching cycle by providing a deadtime, thereby performing soft switching.


Patent
Cosel Co. | Date: 2017-02-10

A switching power supply apparatus is configured of, as a primary-side circuit, a synchronous rectification step-up/down chopper circuit including a main switching element (14), a commutation element (16), a choke coil (18), and a buffer capacitor (20). As a secondary-side circuit, to a secondary winding provided to the choke coil, a series circuit including a rectifying element and an output capacitor is connected. An inductance of the choke coil is set to have a predetermined value so that a choke coil current IL flowing through the choke coil flows in both of a positive direction and a negative direction across zero in one cycle of switching when an output current is equal to or smaller than a maximum output current. A switching control circuit performs control of complementarily turning the main switching element and the commutation element ON/OFF in a switching cycle by providing a deadtime, thereby performing soft switching.


Ishizuka M.,Toyama Prefectural University | Hatakeyama T.,Toyama Prefectural University | Funawatashi Y.,Toyama Prefectural University | Koizumi K.,COSEL Co.
Active and Passive Electronic Components | Year: 2011

In recent years, there is a growing demand to have smaller and lighter electronic circuits which have greater complexity, multifunctionality, and reliability. High-density multichip packaging technology has been used in order to meet these requirements. The higher the density scale is, the larger the power dissipation per unit area becomes. Therefore, in the designing process, it has become very important to carry out the thermal analysis. However, the heat transport model in multichip modules is very complex, and its treatment is tedious and time consuming. This paper describes an application of the thermal network method to the transient thermal analysis of multichip modules and proposes a simple model for the thermal analysis of multichip modules as a preliminary thermal design tool. On the basis of the result of transient thermal analysis, the validity of the thermal network method and the simple thermal analysis model is confirmed. © 2011 Masaru Ishizuka et al.


Patent
Cosel Co. | Date: 2011-01-19

Provided is a switching power supply device that can limit the generation of recovery current of diodes connected in parallel between the two ends of a synchronized rectifying element by the addition of a simple circuit, and that improves efficiency and facilitates miniaturization. The device comprises a synchronized rectifying element (SR1) that turns on and off complementarily with a main oscillation element (TR1) that is connected in series with an input power supply (E), and a parasitic diode (DSR1) that is connected to the two ends of the synchronized rectifying element (SR1) in a direction enabling current supply toward a smoothing circuit (16). The device is equipped with a control circuit (PW2) that generates a control pulse with which is set the time delay for turning on the oscillation element (TR1) after a certain period of time after the synchronized rectifying element (SR1) is turned off has elapsed, and that drives the main oscillation element (TR1) and the synchronized rectifying element (SR1) based on the control pulse. An auxiliary rectification circuit (22) comprising a series circuit formed by an auxiliary switch element (Q1) and an auxiliary capacitor (C1) driven by the control circuit (PW2) is provided between the two ends of the parasitic diode (DSR1).


Patent
COSEL Co. | Date: 2012-07-25

A control circuit (24) includes a calculation means (28) which determines ON time and OFF time of a main switching element (14) and a drive pulse generating means (30) which generates drive pulses that turn the main switching element (14) ON and OFF. A control function formula which prescribes a relationship between an output voltage (Vo) and an output differential value (Vd) by a negative linear function and the like is defined in the calculation means (28). The calculation means (28) samples an input voltage signal (Vi) and an output voltage signal (Vo) at a timing synchronized with a switching cycle of the main switching element (14), and calculates the ON time and OFF time of the main switching element (14) thereafter so as to satisfy the control function formula. The drive pulse generating means (30) generates drive pulses (V14) which turn the main switching element (14) ON and OFF on the basis of the ON and OFF time determined by the calculation means (28).


Patent
Cosel Co. | Date: 2014-06-04

A control circuit (24) includes a calculation means (28) which determines ON time and OFF time of a main switching element (14) and a drive pulse generating means (30) which generates drive pulses that turn the main switching element (14) ON and OFF. A control function formula which prescribes a relationship between an output voltage (Vo) and an output differential value (Vd) by a negative linear function and the like is defined in the calculation means (28). The calculation means (28) samples an input voltage signal (Vi) and an output voltage signal (Vo) at a timing synchronized with a switching cycle of the main switching element (14), and calculates the ON time and OFF time of the main switching element (14) thereafter so as to satisfy the control function formula. The drive pulse generating means (30) generates drive pulses (V14) which turn the main switching element (14) ON and OFF on the basis of the ON and OFF time determined by the calculation means (28).


Patent
Cosel Co. | Date: 2010-10-25

A control function formula which provides a relationship between an output voltage signal Vo and an output differential value with, for example, a negative linear function is defined in a calculation means. The calculation means samples an input voltage signal, an output voltage signal and an output differential signal at time instants in synchronization with a cycle of switching of a main switching element, and calculates subsequent ON and OFF durations of the main switching elements such that the control function formula might be satisfied. A drive pulse generation means generates a drive pulse with which the main switching element is turned on and off based on the ON and OFF durations determined by the calculation means. The output differential signal is generated by, for example, a capacitor current detection means or an observer device which detect a current of a smoothing capacitor.


Patent
Cosel Co. | Date: 2010-08-11

A switching power source device includes current control pulse generating means 32 configured of a target value setting module 32a, which outputs a changeable value which is a predetermined target value relating to a control of an output current, a computing module 32b, which carries out a computing process relating to the control of the output current based on the target value, and outputs a computation result, and a pulse generating module 32c, which generates a current control pulse voltage for controlling the output current based on the computation result. The switching power source device includes a current detecting circuit 38, which detects the output current or a current flowing in a switching element TR1, and a current limit signal generating circuit 36 which, when the detected current exceeds a reference value set based on the output of the current control pulse generating means 32, outputs a current limit signal for limiting the current. A drive pulse generating circuit 18, on the current limit signal being output, operates in such a way that an on-duty of a drive pulse stops widening, or becomes narrower.


Eco

Trademark
COSEL Co. | Date: 2011-05-18

High-frequency switching power supplies; apparatus for power factor correction; power supply converters; switching regulators; power line filters; apparatus and instruments for regulating or controlling electric current.


Trademark
COSEL Co. | Date: 2011-01-18

High-frequency switching power supplies; apparatus for power factor correction; power supply converters; switching regulators; power line filters.

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