Switched-mode power supply and method for operating a switched-mode power supply

Patent metadata

Field	Value
Publication number	US-10250147-B2
Application number	US-201815925413-A
Country	US
Kind code	B2
Filing date	Mar 19, 2018
Priority date	Mar 21, 2017
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

A switch-mode power supply includes a control element in a primary circuit for controlling a transformer for transmitting electric energy from the primary circuit to a secondary circuit, a first regulating element in the secondary circuit for regulating an electric output variable of the secondary circuit, and a second regulating element in the primary circuit for regulating an electric controlled variable of the control element as a function of a temperature of the primary circuit, the second regulating element being thermally coupled to an element of the primary circuit whose temperature is to be ascertained.

First claim

What is claimed is:

1. A switch-mode power supply, having:
a control element situated in a primary circuit for controlling a transformer with the aid of an electric controlled variable;
an ascertainment device that is situated in a secondary circuit for ascertaining an electric output variable of the secondary circuit;
a first regulating element that is situated in the secondary circuit, functionally connected with the control element, and configured to regulate the electric output variable of the secondary circuit;
a coupling element, interconnected between the primary circuit and the secondary circuit, functionally connecting the ascertainment device with the control element for transmitting the ascertained electric output variable of the secondary circuit to the control element of the first circuit; and
a second regulating element that is situated in the primary circuit for regulating the electric controlled variable of the control element as a function of a temperature of an element of the primary circuit ascertained by the second regulating element, wherein the second regulating element is connected in parallel to the coupling element.

2. The switched-mode power supply of claim 1 , wherein the electric controlled variable is an electric current, an electric voltage, or a digital variable.

3. The switched-mode power supply of claim 2 , wherein a switching rate of one or more switches of the control element for the electric controlled variable of the control element is adjustable.

4. The switched-mode power supply of claim 1 , wherein the second regulating element is configured to influence the electric controlled variable of the control element to ensure that a specifiable temperature threshold value for the element of the primary circuit is not exceeded.

5. The switched-mode power supply of claim 1 , wherein the second regulating element is a resistor.

6. The switched-mode power supply of claim 5 , wherein the resistor is an NTC thermistor interconnected in the primary circuit in such a way that it provides an electric regulating current in a control direction.

7. The switched-mode power supply of claim 5 , wherein the resistor is a PTC thermistor interconnected in the primary circuit in such a way that it provides an electric regulating current in a control direction.

8. The switched-mode power supply of claim 1 , wherein the switched-mode power supply is a resonance converter.

9. A method for operating a switched-mode power supply, the method comprising:
a. ascertaining an electric output variable of a secondary circuit of the switched-mode power supply;
b. changing a first electric controlled variable based on the ascertained electric output variable;
c. ascertaining a temperature of an element in a primary circuit of the switched-mode power supply;
d. changing a second electric controlled variable based on the ascertained temperature in the primary circuit;
e. adapting a control by a control element based on a sum of the first electric controlled variable and the second electric controlled variable; and
f. changing an electric power output that is transmitted in a transformer based on the ascertained temperature of the element of the primary circuit;
wherein steps a and b are performed in succession, steps c and d are performed in succession, and the performance of the pair of steps of a and b is simultaneous to the performance of the pair of steps of c and d.

10. The method of claim 9 , wherein the adapting of the control by the control element is performed in a manner by which electric power transmitted from the primary circuit to the secondary circuit is reduced when the temperature of the element in the primary circuit exceeds a predefined threshold value.

Assignees

• Bosch Gmbh Robert

Inventors

• Mack Juergen
• Seibert Marc-Alexandre

Classifications

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title

• H02M1/32 Primary

  Means for protecting converters other than automatic disconnection · CPC title

• H02M2001/0032

  Electricity · mapped topic

• H02M3/3385

  with automatic control of output voltage or current (H02M3/33561 takes precedence) · CPC title

• H02M1/4241

  using a resonant converter · CPC title