Power supply and medical system

Patent metadata

Field	Value
Publication number	US-11050343-B2
Application number	US-202016821167-A
Country	US
Kind code	B2
Filing date	Mar 17, 2020
Priority date	Mar 25, 2019
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

A power supply includes: a power factor correction circuit that includes a capacitor and converts an input voltage, produced by rectifying an AC input voltage, to a DC, output voltage; a current detector that detects an inflow current for the power factor correction circuit and outputs a current detection signal; an output voltage detector that detects the output voltage and outputs an output voltage detection signal; a voltage difference detector that detects a voltage difference between maximum and minimum values of a pulsation component of the output voltage detected from the output voltage detection signal; a working life determiner that compares the voltage difference and a threshold and gives notification of end of life of the capacitor when the voltage difference reaches the threshold; and a threshold updater that updates the threshold in keeping with the detected inflow current detected based on the current detection signal.

First claim

What is claimed is:

1. A power supply comprising:
a power factor correction circuit that includes an inductor, a diode, a switch, and a capacitor, converts an input voltage, produced by rectifying an alternating current (AC) voltage, to a direct current (DC) voltage, and outputs the DC voltage;
a current detector that detects an inflow current inputted into the power factor correction circuit and outputs a current detection signal;
an output voltage detector that detects the DC voltage and outputs an output voltage detection signal;
a voltage difference detector that detects one voltage difference value out of a voltage difference value between a maximum value and a minimum value of a pulsation component of the DC voltage detected from the output voltage detection signal, a voltage difference value between a voltage value of the DC voltage at timing where the pulsation component reaches the maximum value and a voltage value of a target voltage for the DC voltage, and a voltage difference value between a voltage value of the DC voltage at timing where the pulsation component reaches the minimum value and the voltage value of the target voltage;
a working life determiner that compares the one voltage difference value and a comparison threshold set in advance and gives notification of an end of working life of the capacitor being reached when the voltage difference value has reached the comparison threshold; and
a threshold updater that updates the comparison threshold to a threshold in keeping with a current value of the inflow current detected based on the current detection signal.

2. The power supply accord in to claim 1 ,
further comprising an input detector that detects a voltage produced by rectifying the AC voltage and outputs an input voltage detection signal,
wherein the threshold updater updates the comparison threshold to a threshold in keeping with a voltage value of the AC voltage detected based on the input voltage detection signal, out of a plurality of the thresholds for the current value of the inflow current that are present for each voltage value of the AC voltage.

3. A medical system comprising:
the power supply according to claim 2 that further includes a pair of input terminals connected to an input line, a primary-side rectifier that is connected via a pair of power supply lines to the pair of input terminals, rectifies the AC voltage inputted via the input line, the pair of input terminals, and the pair of power supply lines, and outputs as the input voltage to the power factor correction circuit, an isolation DC/DC converter that generates a load voltage for a corresponding load from the DC voltage and outputs the load voltage, and a fuse or a breaker interposed on the pair of power supply lines; and
a medical appliance that is connected as the load to the isolation DC/DC converter and operates based on the load voltage.

4. A medical system comprising:
the power supply according to claim 2 that further includes a pair of input terminals connected to an input line, a primary-side rectifier that is connected via a pair of power supply lines to the pair of input terminals, rectifies the AC voltage inputted via the input line, the pair of input terminals, and the pair of power supply lines, and outputs as the input voltage to the power factor correction circuit, an isolation DC/DC converter that generates a load voltage for a corresponding load from the DC voltage and outputs the load voltage, and a first fuse or a first breaker interposed on one power supply line out of the pair of power supply lines;
a second fuse or a second breaker interposed on the input line connected via the input terminals to another power supply line out of the pair of power supply lines; and
a medical appliance that is connected as the load to the isolation DC/DC converter and operates based on the load voltage.

5. The power supply according to claim 2 ,
wherein on being notified of the end of working life being reached by the working life determiner, the power factor correction circuit causes the switch to stop switching operations.

6. A medical system comprising:
the power supply according to claim 5 that further includes a pair of input terminals connected to an input line, a primary-side rectifier that is connected via a pair of power supply lines to the pair of input terminals, rectifies the AC voltage inputted via the input line, the pair of input terminals, and the pair of power supply lines, and outputs as the input voltage to the power factor correction circuit, an isolation DC/DC converter that generates a load voltage for a corresponding load from the DC voltage and outputs the load voltage, and a fuse or a breaker interposed on the pair of power supply lines; and
a medical appliance that is connected as the load to the isolation DC/DC converter and operates based on the load voltage.

7. A medical system comprising:
the power supply according to claim 5 that further includes a pair of input terminals connected to an input line, a primary-side rectifier that is connected via a pair of power supply lines to the pair of input terminals, rectifies the AC voltage inputted via the input line, the pair of input terminals, and the pair of power supply lines, and outputs as the input voltage to the power factor correction circuit, an isolation DC/DC converter that generates a load voltage for a corresponding load from the DC voltage and outputs the load voltage, and a first fuse or a first breaker interposed on one power supply line out of the pair of power supply lines;
a second fuse or a second breaker interposed on the input line connected via the input terminals to another power supply line out of the pair of power supply lines; and
a medical appliance that is connected as the load to the isolation DC/DC converter and operates based on the load voltage.

8. The power supply according to claim 1 ,
wherein on being notified of the end of working life being reached by the working life determiner, the power factor correction circuit causes the switch to stop switching operations.

9. A medical system comprising:
the power supply according to claim 8 that further includes a pair of input terminals connected to an input line, a primary-side rectifier that is connected via a pair of power supply lines to the pair of input terminals, rectifies the AC voltage inputted via the input line, the pair of input terminals, and the pair of power supply lines, and outputs as the input voltage to the power factor correction circuit, an isolation DC/DC converter that generates a load voltage for a corresponding load from the DC voltage and outputs the load voltage, and a first fuse or a first breaker interposed on one power supply line out of the pair of power supply lines;
a second fuse or a second breaker interposed on the input line connected via the input terminals to another power supply line out of the pair of power supply lines; and
a medical appliance that is connected as the load to the isolation DC/DC converter and operates based on the load voltage.

10. A medical system comprising:
the power supply according to claim 8 that further includes a pair of input, terminals connected to an input line, a primary-side rectifier that is connected via a pair of power supply lines to the pair of input terminals, rectifies the AC voltage inputted via the input, line, the pair of input terminals, and the pair of power supply lines, and outputs as the input voltage to the power factor correction circuit, an isolation DC/DC converter that generates a load voltage for a corresponding load from the DC voltage and outputs the load voltage, and a fuse or a breaker interposed on the pair of power supply lines; and
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Assignees

• Tdk Corp

Inventors

• Takegami Eiji

Classifications

• H02M1/4225 Primary

  using a non-isolated boost converter · CPC title

• H02M1/4208 Primary

  Arrangements for improving power factor of AC input · CPC title

• H02M1/14

  Arrangements for reducing ripples from DC input or output · CPC title

• H02M3/33523

  with galvanic isolation between input and output of both the power stage and the feedback loop · CPC title

• Y02B70/10

  Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes · CPC title