An energy-saving control circuit with low-power standby

Abstract

The present invention relates to the technical field of standby circuits, and specifically, to an energy-saving control circuit for low-power standby. It includes a power supply module, a main control module, a low-power standby module, and a wake-up module. The low-power standby module includes a standby control unit, a clock frequency division unit, and an energy storage unit. The wake-up module includes a pre-wake-up unit and a cache unit. The power supply module is connected to the wake-up module and the main control module, and the main control module is connected to the low-power standby module. The present invention detects the current of each functional module, and then the clock frequency division unit completes the frequency division processing of each module, adjusts the energy distribution of each module by the energy storage unit, achieves the purpose of precise energy saving, and stores the previous data files through the pre-wake-up unit and the cache unit. When the pre-wake-up unit is started, the data is directly read from the cache unit to ensure that the electrical equipment can respond quickly.

Description

Technical Field

[0001] The present invention relates to the technical field of standby circuits, and more specifically, to an energy-saving control circuit for low-power standby. Background Art

[0002] The low-power standby mode has a wide range of applications in various electronic devices. Its main purpose is to reduce energy consumption when the device is inactive, thereby extending the battery life or reducing the overall energy consumption. The advantage of the low-power standby mode is that it can significantly reduce the power consumption of the device without affecting its functions, extend the battery life, and improve the energy efficiency of the device. In the low-power standby mode, the device reduces power consumption in various ways. First, the processor usually reduces the clock frequency or enters a low-power state to reduce power consumption. Second, the device turns off some unnecessary functional modules. For example, the display may turn off the backlight or enter a low-power mode, and the wireless communication module may reduce the transmission power or enter a sleep state, which can significantly reduce the overall power consumption of the device.

[0003] Currently, after some large electrical appliances enter the low-power standby mode, some unnecessary functional modules are turned off, and some functional modules enter a low-frequency operating mode. The energy consumption of different functional modules in the low-frequency operating mode is also different. If the same power supply mode is adopted, it will cause energy waste and cannot achieve the purpose of precise energy saving. Moreover, when the electrical appliance experiences a long-term low-power standby mode, it will lead to a long wake-up time, affecting normal use. Therefore, we propose an energy-saving control circuit for low-power standby. Summary of the Invention

[0004] The purpose of the present invention is to provide an energy-saving control circuit for low-power standby to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides an energy-saving control circuit for low-power standby, including a power supply module, a main control module, a low-power standby module, and a wake-up module. The low-power standby module includes a standby control unit, a clock frequency division unit, and an energy storage unit. The wake-up module includes a pre-wake-up unit and a cache unit. The power supply module is connected to the wake-up module and the main control module, and the main control module is connected to the low-power standby module;

[0006] The power supply module converts the mains alternating current into direct current through a constant voltage rectification circuit to supply power to the main control chip. When the control chip transmits a signal to enter the low-power mode, the standby control unit of the low-power standby module first turns off the unnecessary functional modules, then detects the current of each functional module, and transmits the detected current value signal to the clock frequency division unit. The clock frequency division unit completes the frequency division processing of each module and adjusts the energy distribution of each module by the energy storage unit.

[0007] As a further improvement of this technical solution, the power supply module includes a constant-voltage rectification circuit, and the constant-voltage rectification circuit includes a transformer T and a rectifier bridge BG connected to the secondary winding of the transformer T;

[0008] The primary winding of the transformer T is connected to the mains power supply. One end of the rectifier bridge BG is connected to a resistor R1 and a capacitor C1 in parallel. The other end of the rectifier bridge BG is connected to the positive pole of a zener diode VD, the capacitor C1, and the other end of a capacitor C2. The resistor R1 is connected to the negative pole of the zener diode VD and the other end of the capacitor C2.

[0009] As a further improvement of this technical solution, the standby control unit includes a current detection circuit and a control switch circuit. Among them, the current detection circuit includes an operational amplifier A, a MOS transistor V1, and a diode D2;

[0010] Pin 1 of the operational amplifier A is connected to a resistor R5. Pin 2 of the operational amplifier A is connected to a resistor R7 and the other end of the resistor R5. Pin 3 of the operational amplifier A is connected to a resistor R6 and a resistor R8 in parallel. The other end of the resistor R6 is grounded. The other end of the resistor R8 is connected to a resistor R9 and the power supply VCC. The other end of the resistor R9 is connected to the other end of the resistor R7 and is connected to a load. The load is connected to the drain of the MOS transistor V1 and the negative pole of the diode D2. The source of the MOS transistor V1 is connected to the positive pole of the diode D2 and is grounded.

[0011] As a further improvement of this technical solution, a MOS transistor and a diode D2 are connected between the power supply VCC of the current detection circuit and the load, and the MOS transistor is used to switch different functional modules in the load to detect the currents of different functional modules.

[0012] As a further improvement of this technical solution, the control switch circuit includes a triode VT1, a zener diode D1, and a capacitor C3;

[0013] The base of the triode VT1 is connected to a resistor R2 and a resistor R3 in parallel. The other end of the resistor R2 is connected to the negative pole of the zener diode D1. The positive pole of the zener diode D1 is connected to the power supply VCC. The other end of the resistor R3 is connected to the emitter of the triode VT1 and the capacitor C3. The collector of the triode VT1 is connected to a resistor R4 and the other end of the capacitor C3.

[0014] As a further improvement of this technical solution, a capacitor C3 is added between the collector and the emitter of the triode VT1 in the control switch circuit to eliminate the high-frequency oscillation generated by the triode VT1 when controlling the on / off of the circuit.

[0015] As a further improvement of the technical solution, the clock frequency division unit uses a PLL chip to divide the frequency of the current signal detected by the standby control unit, and at the same time tracks and locks the divided current of different functional modules.

[0016] As a further improvement of the technical solution, the wake-up module includes a pre-wake-up unit and a cache unit. The pre-wake-up unit is internally provided with an RTC chip, which can maintain time counting in a low-power state and trigger wake-up when the set time arrives or a specific signal is received.

[0017] As a further improvement of the technical solution, the cache unit stores the data files before the electrical appliance enters the low-power standby state. When the pre-wake-up unit starts, it directly reads the data from the cache unit to ensure that the electrical appliance can be quickly put into use.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. For the energy-saving control circuit with low-power standby, after the electrical appliance enters the low-power standby mode, the current detection circuit of the standby control unit in the low-power standby module detects the current of each functional module, and transmits the detected current numerical signal to the clock frequency division unit. The clock frequency division unit completes the frequency division processing of each module, adjusts the energy distribution of the energy storage unit to each module, realizes the reasonable distribution of energy supply to each functional module, and achieves the purpose of precise energy saving.

[0020] 2. Through the pre-wake-up unit in the wake-up module, the RTC chip can maintain time counting in a low-power state and trigger wake-up when the set time arrives or a specific signal is received, realizing the timed start of the electrical appliance equipment. And the cache unit stores the data files before the electrical appliance enters the low-power standby state. When the pre-wake-up unit starts, it directly reads the data from the cache unit to ensure that the electrical appliance equipment can respond quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the overall flow schematic diagram of the present invention;

[0022] Figure 2 is the schematic diagram of the standby control unit of the present invention;

[0023] Figure 3 is the constant voltage rectification circuit diagram of the present invention;

[0024] Figure 4 is the control switch circuit diagram of the present invention;

[0025] Figure 5 is the current detection circuit diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] The low-power standby mode has a wide range of applications in various electronic devices. Its main purpose is to reduce energy consumption when the device is inactive, thereby extending the battery life or reducing the overall energy consumption. The advantage of the low-power standby mode is that it can significantly reduce the power consumption of the device, extend the battery life, and improve the energy efficiency of the device without affecting the device's functions. In the low-power standby mode, the device reduces power consumption in various ways. First, the processor usually reduces the clock frequency or enters a low-power state to reduce power consumption. Second, the device turns off some unnecessary functional modules. For example, the display may turn off the backlight or enter a low-power mode, and the wireless communication module may reduce the transmission power or enter a sleep state, which can significantly reduce the overall power consumption of the device.

[0028] Please refer to Figures 1 - 5 As shown, the present invention provides an energy-saving control circuit for low-power standby, including a power supply module, a main control module, a low-power standby module, and a wake-up module. The low-power standby module includes a standby control unit, a clock frequency division unit, and an energy storage unit. The wake-up module includes a pre-wake-up unit and a cache unit. The power supply module is connected to the wake-up module and the main control module, and the main control module is connected to the low-power standby module;

[0029] The power supply module converts the mains alternating current into direct current through a constant-voltage rectification circuit to supply power to the main control chip. When the control chip transmits a signal to enter the low-power mode, the standby control unit of the low-power standby module first turns off the unnecessary functional modules, then detects the current of each functional module, and transmits the detected current value signal to the clock frequency division unit. The clock frequency division unit completes the frequency division processing of each module and adjusts the energy distribution of each module by the energy storage unit.

[0030] Principle: After the electrical appliance enters the low-power standby mode, the energy-saving control circuit for low-power standby uses the current detection circuit of the standby control unit in the low-power standby module to detect the current of each functional module, and transmits the detected current value signal to the clock frequency division unit. The clock frequency division unit completes the frequency division processing of each module, adjusts the energy distribution of the energy storage unit to each module, realizes the reasonable distribution of power supply to each functional module, and achieves the purpose of precise energy saving. By means of the pre-wake-up unit in the wake-up module, the timing start of the electrical equipment is realized, and the buffer unit stores the data files before the electrical appliance enters the low-power standby state. When the pre-wake-up unit starts, the data is directly read from the buffer unit to ensure that the electrical equipment can respond quickly.

[0031] In order to convert the alternating current of the mains into direct current to supply power to the main control chip. Among them, the power supply module includes a constant voltage rectification circuit, and the constant voltage rectification circuit includes a transformer T and a rectifier bridge BG connected to the secondary winding of the transformer T.

[0032] The primary winding of the transformer T is connected to the mains. One end of the rectifier bridge BG is connected to the resistor R1 and the capacitor C1 in parallel. The other end of the rectifier bridge BG is connected to the positive pole of the zener diode VD, the capacitor C1 in parallel, and the other end of the capacitor C2. The resistor R1 is connected to the negative pole of the zener diode VD and the other end of the capacitor C2.

[0033] In this circuit, the rectifier bridge BG converts the alternating current into pulsating direct current, which is smoothed by the capacitors C1 and C2, and then the constant voltage direct current is output by the zener diode VD, realizing the conversion from alternating current to direct current and ensuring the normal operation of the main control chip.

[0034] In order to detect the current of each functional module. Among them, the standby control unit includes a current detection circuit and a control switch circuit. Among them, the current detection circuit includes an operational amplifier A, a MOS transistor V1, and a diode D2.

[0035] The pin 1 of the operational amplifier A is connected to the resistor R5. The pin 2 of the operational amplifier A is connected to the resistor R7 and the other end of the resistor R5. The pin 3 of the operational amplifier A is connected to the resistor R6 and the resistor R8 in parallel. The other end of the resistor R6 is grounded. The other end of the resistor R8 is connected to the resistor R9 and the power supply VCC. The other end of the resistor R9 is connected to the other end of the resistor R7 and the load. The load is connected to the drain of the MOS transistor V1 and the negative pole of the diode D2. The source of the MOS transistor V1 is connected to the positive pole of the diode D2 and grounded.

[0036] In this circuit, the virtual short and virtual open of operational amplifier A are used to detect the currents of each functional module in the load. From the virtual open, it can be known that the current flowing through resistor R6 is equal to the current flowing through resistor R8. From the virtual short, it can be known that the voltages at pins 2 and 3 of operational amplifier A are equal, and the currents on the circuit of pin 2 of operational amplifier A are equal. Resistors R7 and R8 have the same resistance value. When the current of the load is detected, resistor R9 shunts it. According to the voltage difference between pin 3 and pin 2 of operational amplifier A divided by resistor R5, the detected value of the current is obtained, realizing the detection of the currents of each functional module.

[0037] In order to more conveniently switch each functional module, a MOS transistor and diode D2 are connected between the power supply VCC of the current detection circuit and the load. By controlling the gate voltage of the MOS transistor, its conduction state can be changed. When the gate voltage is high, the MOS transistor conducts, connecting the corresponding measurement channel to the detection circuit. When the gate voltage is low, the MOS transistor is cut off, switching to other measurement channels. The MOS transistor is used to switch different functional modules in the load to detect the currents of different functional modules.

[0038] In order to better turn off unnecessary functional modules, the control switch circuit includes transistor VT1, zener diode D1, and capacitor C3;

[0039] The base of transistor VT1 is connected to resistor R2 and also connected to resistor R3. The other end of resistor R2 is connected to the negative electrode of zener diode D1. The positive electrode of zener diode D1 is connected to power supply VCC. The other end of resistor R3 is connected to the emitter of transistor VT1 and also connected to capacitor C3. The collector of transistor VT1 is connected to resistor R4 and also connected to the other end of capacitor C3.

[0040] In this circuit, when the input voltage is less than the breakdown voltage of zener diode D1, zener diode D1 is cut off. At this time, the base of transistor VT1 does not have enough voltage to make it conduct, and transistor VT1 is in the cut-off state. No current flows through load resistor R4, and the load does not work. When the input voltage rises and reaches the breakdown voltage of zener diode D1, the zener diode conducts, providing a stable voltage for the base of transistor VT1, making the base voltage of transistor VT1 high enough, and transistor VT1 enters the saturation state. At this time, the collector and emitter of transistor VT1 are approximately short-circuited, and current can pass through load resistor R4, and the load starts to work. The zener diode is used to detect the change of the input voltage. When the voltage reaches the set value, the transistor is controlled to conduct, realizing the control of the load.

[0041] To eliminate the high-frequency oscillation generated by the triode VT1 when controlling the on / off of the circuit, a capacitor C3 is added between the collector and emitter of the triode VT1 in the control switch circuit. Increasing the collector-emitter capacitance can change the frequency response characteristics of the circuit and eliminate or reduce this oscillation. This is because the capacitor can shunt or filter high-frequency signals, reducing the gain of the circuit at certain frequency points, thereby suppressing the generation of oscillation.

[0042] To better divide the detected current signal, the clock division unit uses a PLL chip to divide the current signal detected by the standby control unit and simultaneously track and lock the divided currents of different functional modules, where:

[0043] The PLL phase-locked loop mainly consists of a phase comparator, a low-pass filter, a voltage-controlled oscillator, and a frequency divider, etc. The phase comparator compares the phase difference between the input signal and the output signal of the voltage-controlled oscillator and generates an error signal proportional to the phase difference. The low-pass filter filters the error signal to remove high-frequency noise and obtains a DC control voltage. The voltage-controlled oscillator adjusts the output frequency according to the control voltage to keep it synchronized with the frequency and phase of the input signal. The frequency divider divides the output signal of the voltage-controlled oscillator to generate the required output frequency. By continuously adjusting the output frequency of the voltage-controlled oscillator, the PLL phase-locked loop can achieve tracking and locking of the input signal, thus realizing the functions of frequency synthesis and clock synchronization.

[0044] Through the tracking and locking of the input signal by the PLL phase-locked loop, the divided signals of each functional module are obtained. The control chip controls the energy storage unit to provide the corresponding divided current for it according to the divided signal of the corresponding functional module, ensuring the reasonable distribution of current. When calculating the energy-saving power consumption of the corresponding functional module, first measure the power consumption at the normal operating clock frequency of the system, then reduce the clock frequency through PLL division, and measure the power consumption again. The energy-saving ratio formula is as follows: Energy-saving ratio = (Power consumption without using PLL division - Power consumption after using PLL division) / Power consumption without using PLL division × 100%;

[0045] For example, assume that the power consumption of a system without using PLL division is 100 mW. When the clock frequency is reduced by half using PLL division, the measured power consumption is 80 mW. Then the energy-saving ratio is: (100 mW - 80 mW) / 100 mW × 100% = 20%.

[0046] To ensure that the electrical equipment can quickly enter the working state from the low-power standby mode, the wake-up module includes a pre-wake-up unit and a cache unit. The pre-wake-up unit is internally equipped with an RTC chip, which can maintain time counting in the low-power state and trigger wake-up when the set time arrives or a specific signal is received;

[0047] The RTC chip is a real-time clock chip, an integrated circuit, mainly used for tracking and recording the current date and time. By using the alarm function of the RTC chip, it can achieve timed wake-up. When using the timed wake-up function of the RTC chip, the RTC chip can respond within a few microseconds and provide time information, so as to ensure that the pre-wake-up unit can wake up the electrical device within a few microseconds when the time arrives, and then read the data file stored in the cache unit before the electrical appliance enters the low-power standby state, and quickly enter the working state.

[0048] The energy-saving control circuit for low-power standby supplies power to the main control chip by converting the mains AC power into DC power through a constant-voltage rectification circuit by the power supply module. When the control chip transmits a signal to enter the low-power mode, the standby control unit of the low-power standby module first turns off the unnecessary functional modules, then detects the current of each functional module, and transmits the detected current value signal to the clock frequency division unit. The clock frequency division unit completes the frequency division processing of each module, adjusts the energy distribution of each module by the energy storage unit, and through the pre-wake-up unit in the wake-up module, uses the RTC chip to keep time counting in the low-power state and trigger wake-up when the set time arrives or a specific signal is received, so as to realize the timed start of the electrical equipment, and the cache unit stores the data file before the electrical appliance enters the low-power standby state. When the pre-wake-up unit starts, it directly reads the data from the cache unit to ensure that the electrical equipment can respond quickly.

[0049] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-power standby energy-saving control circuit, characterized in that: It includes a power supply module, a main control module, a low-power standby module and a wake-up module. The low-power standby module includes a standby control unit, a clock frequency division unit and an energy storage unit. The wake-up module includes a pre-wake-up unit and a cache unit. The power supply module and the wake-up module are connected to the main control module, and the main control module is connected to the low-power standby module; The power supply module converts AC power into DC power to supply power to the main control chip through a constant voltage rectifier circuit. When the control chip transmits a signal to enter the low power consumption mode, the standby control unit of the low power consumption standby module first shuts down unnecessary functional modules, then performs current detection on each functional module, and transmits the detected current value signal to the clock frequency division unit, which completes the frequency division processing of each module and adjusts the energy storage unit's energy distribution to each module. The power supply module includes a constant voltage rectifier circuit, and the constant voltage rectifier circuit includes a transformer T and a rectifier bridge BG connected to the secondary winding of the transformer T; The main winding of the transformer T is connected to the mains, one end of the rectifier bridge BG is connected to one end of the resistor R1 and one end of the capacitor C1, the other end of the rectifier bridge BG is connected to the positive electrode of the voltage zener diode VD, the other end of the capacitor C1 and one end of the capacitor C2, the other end of the resistor R1 is connected to the negative electrode of the voltage zener diode VD and the other end of the capacitor C2; The standby control unit includes a current detection circuit and a control switch circuit, wherein the current detection circuit includes an operational amplifier A, a MOS tube V1 and a diode D2; The output terminal of the operational amplifier A is connected to one end of the resistor R5, the negative input terminal of the operational amplifier A is connected to one end of the resistor R7 and the other end of the resistor R5, the positive input terminal of the operational amplifier A is connected to one end of the resistor R6 and one end of the resistor R8, the other end of the resistor R6 is grounded, the other end of the resistor R8 is connected to one end of the resistor R9 and to the ground, the other end of the resistor R9 is connected to the other end of the resistor R7 and connected to the load, the load is connected to the drain of the MOS tube V1 and connected to the cathode of the diode D2, the source of the MOS tube V1 is connected to the anode of the diode D2 and connected to the power supply VCC; A MOS tube and a diode D2 are connected between the power supply VCC of the current detection circuit and the load, and the MOS tube is used to switch different functional modules in the load to detect the current of different functional modules; The control switch circuit includes a transistor VT1, a voltage stabilizing diode D1 and a capacitor C3; The base of the transistor VT1 is connected to one end of the resistor R2 and one end of the resistor R3 in parallel, the other end of the resistor R2 is connected to the cathode of the voltage-stabilizing diode D1, the anode of the voltage-stabilizing diode D1 is connected to the power supply VCC, the other end of the resistor R3 is connected to the emitter of the transistor VT1 and one end of the capacitor C3, the collector of the transistor VT1 is connected to one end of the resistor R4 and the other end of the capacitor C3, and the other end of the resistor R4 is connected to the load; The clock frequency division unit uses a PLL chip to divide the current signal detected by the standby control unit, and simultaneously tracks and locks the frequency division currents of different functional modules; When calculating the energy-saving power consumption of the corresponding functional module, first measure the power consumption at the clock frequency of the normal operation of the system, then reduce the clock frequency through PLL division, and measure the power consumption again. The energy-saving ratio formula is as follows: Energy-saving ratio = (power consumption without using PLL division - power consumption after using PLL division) / power consumption without using PLL division × 100%.

2. The low power standby energy-saving control circuit according to claim 1, characterized in that: A capacitor C3 is added between the collector and emitter of the transistor VT1 of the control switch circuit to eliminate high-frequency oscillations generated by the transistor VT1 when the control circuit is turned on and off.

3. The low power standby energy-saving control circuit according to claim 1, characterized in that: The wake-up module includes a pre-wake-up unit and a cache unit. The pre-wake-up unit is internally provided with an RTC chip. The RTC chip can maintain time counting in a low power consumption state and trigger wake-up when a set time is reached or a specific signal is received.

4. The low power standby energy-saving control circuit according to claim 3, characterized in that: The cache unit stores data files before the appliance enters the low-power standby state. When the pre-wake-up unit is started, data is directly read from the cache unit to ensure that the appliance can be put into use quickly.

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