Power supply power limiting circuit

Abstract

A power supply power limiting circuit comprises a power supply module, a sampling module and a control module which are connected with the power supply module, a comparison module connected with the sampling module, and an optocoupler module connected with the comparison module and the control module. Wherein the sampling module comprises a sampling resistor, and the sampling resistor is connected with a sampling end; the comparison module comprises a comparator; the optocoupler module comprises a light emitting source connected with the output end of the comparator and a light receiving source connected with the control module; one input end of the comparator is connected with a fixed voltage end; and the other input end is connected with the sampling end. The power amplifier has the advantages that the output power of the power supply can be limited, so that the output power of the power amplifier is limited, and the power amplifier can operate normally when the current value is within a reasonable range.

Description

Technical Field

[0001] The utility model relates to the technical field of electronics, in particular to a power supply power limiting circuit. Background Art

[0002] When the output power of the amplifier exceeds the rated power, it is easy to cause various factors such as damage to the amplifier or increase the temperature of the amplifier, which is not conducive to the life of the amplifier. In the traditional switching power supply amplifier circuit, an overcurrent protection device is set to trigger the protection when the current exceeds the limit value, but in this way, there is no output at the output end after the protection, which will seriously affect the use.

[0003] Therefore, it is urgent to develop a power supply power limiting circuit that can limit the output power of the power supply, thereby limiting the output power of the power amplifier, and can operate normally when the current value is within a reasonable range. Utility Model Content

[0004] The utility model aims to solve one of the above technical problems at least to a certain extent.

[0005] Therefore, the purpose of the utility model is to provide a power supply power limiting circuit, which can limit the output power of the power supply, thereby limiting the output power of the power amplifier, and the current value can operate normally within a reasonable range.

[0006] To achieve the above-mentioned purpose, an embodiment of the utility model discloses a power supply power limiting circuit, comprising: a power supply module, a sampling module and a control module connected to the power supply module, a comparison module connected to the sampling module, and an optocoupler module connected to the comparison module and the control module; wherein the sampling module comprises a sampling resistor, and the sampling resistor is connected to a sampling end; the comparison module comprises a comparator; the optocoupler module comprises a light source connected to the output end of the comparator, and a light receiving light connected to the control module; one input end of the comparator is connected to a fixed voltage end; and the other input end is connected to the sampling end.

[0007] In addition, the power supply power limiting circuit according to the above technical solution of the utility model may also have the following additional technical features:

[0008] Optionally, the light source is a light emitting diode, and the light receiving light is a photosensitive diode.

[0009] Optionally, a diode is connected between the comparator and the light source.

[0010] Optionally, a capacitor is connected between the diode and the sampling end.

[0011] Optionally, a first voltage regulating resistor is connected between one input terminal of the comparator and the fixed voltage terminal; and a second voltage regulating resistor is connected between the other input terminal and the sampling terminal.

[0012] Optionally, a short-circuit protection module is provided at the power supply module, the sampling module, or the control module.

[0013] The beneficial effect of the utility model is that the output power of the power supply can be limited, thereby limiting the output power of the power amplifier, and the current value can operate normally within a reasonable range. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a power supply power limiting circuit provided by an embodiment of the utility model;

[0015] Figure 2 The utility model is a circuit diagram of a power supply power limiting circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0016] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or components / elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0017] Figure 1 It is a structural schematic diagram of a power supply power limiting circuit provided by an embodiment of the utility model; Figure 2 FIG. 1 is a circuit diagram of a power supply power limiting circuit provided by an embodiment of the utility model. Figure 1-2 As shown, the power supply power limiting circuit includes: a power supply module, a sampling module and a control module connected to the power supply module, a comparison module connected to the sampling module, and an optical coupling module connected to the comparison module and the control module; wherein the sampling module includes a sampling resistor, and the sampling resistor is connected to a sampling end; the comparison module includes a comparator; the optical coupling module includes a light source connected to the output end of the comparator, and a light receiving light connected to the control module; one input end of the comparator is connected to a fixed voltage end; and the other input end is connected to the sampling end.

[0018] Specifically, Figure 1 is based on Figure 2 The resulting structural diagram is easy to understand. Please refer to it when explaining below. Figure 2The sampling module uses the sampling resistor RC1 to realize the sampling function: when the current flowing through RC1 increases, the voltage drop on it will also increase, and the sampling end is IS; the voltage at the input terminal 6- of the comparator represents the rise and fall of the voltage at the sampling end IS, which is compared with the fixed voltage connected to the input terminal 5+. When the current and the voltage drop exceed the limit value, the output terminal 7 of the comparator becomes a low level, so that the light source UA3A of the optical coupling module is turned on, thereby controlling the receiving light source UA3B to generate a photocurrent signal, and then the control module receives the photoelectric signal, and then controls the power supply to reduce the power, so that the voltage output is reduced, and the output power of the power supply is limited to the set value.

[0019] According to the power supply power limiting circuit of the utility model, the current and voltage in the circuit can be conveniently detected, thereby limiting the output power of the power supply to a limited value; an overcurrent protector is no longer required in the circuit to avoid the circuit being disconnected due to normal current fluctuations, thereby making the circuit run more smoothly.

[0020] According to an embodiment of the utility model, the light source is a light emitting diode, and the light receiving light is a photosensitive diode.

[0021] Specifically, light emitting diodes and photosensitive diodes are relatively cheap components that can achieve relevant effects and can be selected according to actual conditions.

[0022] According to an embodiment of the utility model, a diode is connected between the comparator and the light source.

[0023] Specifically, in order to avoid malfunction of the comparator, a single-phase conducting diode may be provided to isolate the current flow of the light source.

[0024] According to an embodiment of the present utility model, a capacitor is connected between the diode and the sampling end.

[0025] Specifically, in order to prevent the diode from being turned on due to noise at the sampling end, a capacitor may be added to ensure that the circuit does not malfunction.

[0026] According to an embodiment of the present utility model, a first voltage regulating resistor is connected between one input terminal of the comparator and the fixed voltage terminal; and a second voltage regulating resistor is connected between the other input terminal and the sampling terminal.

[0027] Specifically, resistors may be set at both input terminals of the comparator to adjust the voltage setting value.

[0028] According to an embodiment of the utility model, a short circuit protection module is provided at the power supply module, or the sampling module, or the control module.

[0029] Specifically, when the circuit is short-circuited, the circuit should be controlled to be disconnected instead of allowing the control module to reduce power and continue to operate, so a short-circuit protection module can be set for short-circuit protection. The set current threshold in the short-circuit protection module is relatively high, far exceeding the voltage drop caused by the normal current increase, so it will not affect the normal operation of the comparator, and can achieve a double protection effect.

[0030] The above embodiments are preferred implementation schemes of the present application. In addition, the present application may also be implemented in other ways. Any obvious replacement without departing from the concept of the present application is within the protection scope of the present application.

Claims

1. A power supply power limiting circuit, characterized in that: include: A power module, a sampling module and a control module connected to the power module, a comparison module connected to the sampling module, and an optical coupling module connected to the comparison module and the control module; Wherein, the sampling module comprises a sampling resistor, and the sampling resistor is connected to a sampling terminal; The comparison module includes a comparator; The optical coupling module includes a light source connected to the output end of the comparator, and a light receiving source connected to the control module; One input terminal of the comparator is connected to the fixed voltage terminal; the other input terminal is connected to the sampling terminal.

2. A power supply power limiting circuit according to claim 1, characterized in that: The light source is a light emitting diode, and the light receiving light is a photosensitive diode.

3. A power supply power limiting circuit according to claim 1, characterized in that: A diode is connected between the comparator and the light source.

4. A power supply power limiting circuit according to claim 3, characterized in that: A capacitor is connected between the diode and the sampling end.

5. The power limiting circuit according to claim 1, characterized in that: A first voltage regulating resistor is connected between one input terminal of the comparator and the fixed voltage terminal; and a second voltage regulating resistor is connected between the other input terminal and the sampling terminal.

6. A power supply power limiting circuit according to claim 1, characterized in that: The power supply module, the sampling module, or the control module is provided with a short circuit protection module.

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