JP3976694B2 - Power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power source that supplies DC power to a load, and relates to a power source used for an audio power amplifier, for example.
[0002]
[Prior art]
Conventionally, as shown in FIG. 2, in particular, in a power source used for an audio power amplifier, the power source 1 is simply configured to supply power to the load 10. For example, when a large volume is required, the load 10 However, there is a case where the frequency fluctuates suddenly without any prior notice. To keep up with the fluctuation, the switching frequency is constantly increased, the error amplifier gain is always increased, the output capacitor is enlarged, etc. Measures were taken.
[0003]
However, even if such measures are taken, efficiency is wasted even if the switching frequency is simply increased, or if the error amplifier gain is simply increased, the operation becomes unstable or the output capacitor is not connected. When the size is increased, there is a problem that it is impossible to reduce the size and cost of the power source.
[0004]
In addition, some inventions have been invented in order to cope with rapid fluctuations in power output (for example, Patent Document 1).
[Patent Document 1]
JP 2000-252983 A (page 5-7, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, such a power supply uses a capacitor to charge and discharge the capacitor to cope with rapid fluctuations in the power supply output, and it is difficult to reduce the size and cost of the power supply.
[0006]
The present invention has been made in view of the above problems, and provides a highly efficient, small, and inexpensive power source that is fast and responds only when necessary.
[0007]
[Means to solve the problem]
The present invention made to achieve the above object is configured to respond at a higher speed only when necessary, so that waste of efficiency can be eliminated and operation can be stabilized. Further, since the output capacitor may have a normal size, the power supply can be reduced in size and cost.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the accompanying drawings. An embodiment of a power source according to the present invention is shown in FIG. Reference numeral 1 is a power source, and 10 is a load.
[0009]
A power source 1 according to this embodiment includes an interface 2, a control unit 3, and a main circuit 4. The interface 2 is configured to receive a request signal from the load 10 and output the signal to the control unit 3. The control unit 3 includes power control means. When the power control means receives a request from a request signal input through the interface 2, for example, when receiving information on a large volume from the load 10, It is configured to control so as to respond more rapidly to a change in quantity.
[0010]
In the power control means, the switching frequency is increased in accordance with the request signal input through the interface 2 or the gain of the error amplifier is increased in accordance with the request signal. It responds faster than only time. However, as long as the operation state of the power supply 1 can be changed so that it can respond at high speed not only by the method here but also by the change in the amount of power, that means is not limited.
[0011]
Further, the power source 1 is provided with an automatic return means. The automatic return means sets a fixed period, and when the fixed period elapses after the request from the request signal from the load 10 disappears or at the same time as the request from the request signal from the load 10 disappears, It is means for automatically canceling the response and restoring the operating state. In addition, you may make it return based on an operation state, when this fixed period passes from the time of changing an operation state to a high-speed response.
[0012]
In this embodiment, a forced return means is provided together with the automatic return means. This forcible return means outputs a return request signal from the load 10 to the interface 2 by recognizing that the amount of power of the load 10 is almost stable from the load 10 side, regardless of the fixed period set by the automatic return means, This is a means for forcibly canceling the high-speed response by the power control means and returning the operation state to the original state. This makes it possible to respond at high speed only when necessary with higher efficiency.
[0013]
In this embodiment, an automatic return means and a forced return means are provided, and the forced return means works when there is a request from the load 10 to return based on the operation state, and there is no return request signal from the load 10, The automatic return means works when a certain period of time has elapsed from when the operating state is changed to the high-speed response, but any one of these means may be provided.
[0014]
The embodiment is configured as described above and operates as follows. When the request signal output from the load 10 is input to the interface 2 and there is no request based on the request signal, the power supply 1 is in a normal operation state and supplies power to the load 10 from the main circuit 4.
[0015]
In this embodiment, when the volume is suddenly increased, a high-speed response is required, and at this time, a large amount of power is required. At this time, a request based on a request signal output from the load 10 to the power source 1 is input through the interface 2 of the power source 1 a certain time before large power is required. This signal is transmitted to the control unit 3, and the operation state is changed in advance in response to a change in the power amount of the load 10 at high speed by the power control means provided in the control unit 3. At almost the same time, a ready signal is output to the load 10. The power control means increases the switching frequency according to the request signal input at the interface 2 or increases the gain of the error amplifier according to the request signal to supply large power from the main circuit 4 to the load 10. To do.
[0016]
When a large amount of power is no longer needed, and when there is no request by the request signal, it is almost the same time or after a certain time has passed since the request disappears, the automatic return means automatically cancels the high-speed response by the power control means, Return. Thereby, it becomes highly efficient and can respond quickly only when necessary. Further, in this embodiment, a forced return means is provided, and when the return request signal is output from the load 10, the period when the output request signal is almost stable is shorter than the period set by the automatic return means. However, the forcible return means forcibly cancels the high-speed response by the power control means and returns based on the operating state. This makes it possible to respond at high speed only when necessary with higher efficiency.
[0017]
【The invention's effect】
According to the present invention, since it is configured to respond faster when necessary, it is possible to eliminate waste of efficiency and stabilize the operation. Further, since the output capacitor may be of a normal size, there is an effect that the power supply can be reduced in size and cost.
[Brief description of the drawings]
FIG. 1 is a schematic view of an embodiment according to the power source of the present invention.
FIG. 2 is a schematic diagram of a conventional power source.
[Explanation of symbols]
1 Power supply 2 Interface 3 Control unit 4 Main circuit 10 Load

Claims (3)

When a request signal is input from a load and a request is received by the request signal, power control means for controlling the operation state to be changed in advance so as to be able to quickly follow the change in the power consumption amount of the load using a switching means And an automatic return means for returning based on the operating state almost simultaneously with the absence of the request by the request signal, or returning based on the operating state when a set fixed period has passed, and the load At least one of forced return means for returning based on the operating state by a return request signal from the power supply, and when the power control means receives a request from the load request signal, the switching frequency is increased. A power supply characterized by being configured to do so . In the power control unit, when receiving a request by the request signal of the load, the power supply of claim 1, wherein the is arranged to increase the gain of the error amplifier. The power supply according to claim 1 or 2, wherein the load is configured to notify the load that the load is ready to follow a change in electric energy.

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