Electronic system optimizing power consumption of cooking appliances in standby mode

Abstract

The invention is a power management circuit for a cooking appliance comprising a mains input (1); a main capacitor (12) to which the mains input (1) is connected such that it transmits electricity as alternating current; a rectifier (2) to which the main capacitor (12) is connected in series; a load (3) to which the rectifier (2) supplies direct current; and a load sensor (26) connected to the input of the load (3) such that it controls the load state. The power management circuit further comprises an auxiliary capacitor (14) connected in parallel to the main capacitor (12) so as to form an adaptive load balancer module (10), and a switch (16) connected such that it selectively activates the auxiliary capacitor (14); a switch driver (28) that opens the switch (16) in a standby state where there is no load demand and closes the switch (16) when there is a load demand; and a microcontroller (22) that operates the switch driver (28) to which it is connected such that it closes and opens the switch according to the load demand transmitted by the load sensor (26).

Description

[0001] ELECTRONIC SYSTEM OPTIMIZING POWER CONSUMPTION OF COOKING APPLIANCES IN STANDBY MODE

[0002] TECHNICAL FIELD

[0003] The invention relates to a circuit structure and method that manages the power consumption of a cooking appliance in standby mode.

[0004] PRIOR ART

[0005] In the known art, AC-DC power supplies utilizing capacitive drop impedance are widely used, particularly to supply control circuits requiring low current. Here, rectifying only the half-waves (positive or negative) of the mains voltage and stabilization via a Zener diode stands out as a typical solution. The Zener diode at the output stage sets the desired output voltage, and a capacitor (usually electrolytic) is connected in parallel to the circuit to reduce the fluctuation of this voltage. Along with this approach, the series capacitor (charge capacitor) positioned at the input determines the value of the current drawn by the circuit, thereby performing the basic current limitation of the system.

[0006] However, one of the most significant problems of conventional capacitive pump type power supplies is that a constant and often unnecessarily high current is continuously drawn from the mains, even when there are low current requirements for the load (e.g., a digital control system). This situation leads to relatively high power consumption even when the appliance is in the standby position, and as international energy efficiency standards become stricter day by day, this approach turns into a significant disadvantage, especially in household electrical appliances.

[0007] In typical examples found in the literature, although the simplicity and low cost of said power supplies are reasons for preference, it is seen that the conventional capacitive supply method remains limited when an adjustable output current is needed or when the power supply is expected to consume as little energy as possible in standby mode. Using a single Zener and a single charge capacitor makes it difficult to provide the different current levels required in different operating phases, and the capacitor initially exhibiting a short-circuit effect in the circuit can also create additional design challenges.In addition, an increase in the capacity of the said charge capacitor causes larger transient currents to flow, especially when the circuit is first energized, thereby causing the circuit elements to be exposed to higher thermal and electrical loads. For this reason, the use of a fixed and large capacitive drop can create an undesirable situation in terms of both cost and reliability. As also stated in document ITT020070220A1, although various arrangements have been proposed to increase the efficiency of known capacitive pump circuits, the limitations originating directly from the used capacitor and Zener-based structure itself have not been completely eliminated.

[0008] BRIEF DESCRIPTION OF THE INVENTION

[0009] The object of the invention is to increase the energy efficiency of cooking appliances in standby states.

[0010] In order to achieve the above objective, the invention is a power management circuit for a cooking appliance comprising a mains input; a main capacitor to which the mains input is connected in such a way to transmit electricity as alternating current; a rectifier to which the main capacitor is connected in series; a load to which the rectifier supplies direct current; and a load sensor connected to the load input in such a way to control the load status. The power management circuit comprises an auxiliary capacitor connected in parallel to the main capacitor so as to form an adaptive load balancer module, and a switch connected so as to selectively activate the auxiliary capacitor; a switch driver that opens the switch in a standby state where there is no load demand and closes the switch when there is a load demand; and a microcontroller that operates the switch driver to which it is connected so as to close and open the switch according to the load demand transmitted by the load sensor. Thus, the auxiliary capacitor is activated and deactivated according to the power demand of the appliance, thereby increasing energy efficiency and preventing unnecessary energy consumption in the standby state.

[0011] In a preferred embodiment of the invention, it comprises a voltage sensor connected to the mains input and reporting the alternating current value coming from the mains to the microcontroller, and is configured such that if the current transmitted by the voltage sensor to the microcontroller is below a predetermined threshold value, it causes the switch driver to close the switch. Thus, the alternating current at the mains input is continuously monitored by the microcontroller, and in the event it falls below the determined threshold value, the systemautomatically closes the switch, activates the auxiliary capacitor, and provides the necessary energy.

[0012] In a preferred embodiment of the invention, the microcontroller is configured such that it causes the switch driver to open the switch when the predetermined threshold value is exceeded. Thus, when the current value monitored by the microcontroller exceeds the predetermined threshold value, the system automatically opens the switch, deactivating the auxiliary capacitor, thereby preventing damages that may arise from overcurrent and ensuring the safe and efficient operation of the appliances.

[0013] In a preferred embodiment of the invention, the predetermined threshold value is at least 210 volts. Thus, it ensures that the system safely identifies the normal operating voltage and allows the auxiliary capacitor to be automatically activated at voltages falling below this level.

[0014] In a preferred embodiment of the invention, the load demand created by the load is at least 20 watts in order for the switch driver to be operated so as to close the switch. Thus, the switch driver closes the switch only when there is sufficient power demand, activating the auxiliary capacitor and ensuring the efficient operation of the system.

[0015] In a preferred embodiment of the invention, the switch driver is configured to open the switch in the event that the load demand drops below 20 watts. Thus, a compact structure is obtained. Thus, the switch driver opens the switch, saving energy and enabling the system to operate more efficiently under low power conditions.

[0016] In a preferred embodiment of the invention, the switch is connected in series to the auxiliary capacitor. Thus, it balances the voltage fluctuations in the circuit, ensuring a more stable and reliable operation of the system. This structure minimizes the negative effects of sudden voltage changes on the switch and increases overall performance.

[0017] In a preferred embodiment of the invention, the mains input voltage is 110-220 volts. Thus, it makes it possible for the appliance to adapt to different voltage standards, ensuring its safe and stable operation in a wide usage environment. This flexibility ensures that the appliance is operated smoothly in various geographic regions and on different power supplies.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic representation of the power management circuit of a domestic oven according to the invention.

[0019] DETAILED DESCRIPTION OF THE INVENTION

[0020] In this detailed description, the improvement subject to the invention is explained with references to examples without forming any limitation and solely for a better understanding of the subject.

[0021] Figure 1 shows the power management circuit structure of a domestic oven. The circuit structure comprises a mains input (1); and a main capacitor (12) to which the mains input (1) transmits alternating current. There is an auxiliary capacitor (14) connected in parallel to the main capacitor (12). There is a switch (16) connected in series to the auxiliary capacitor (14) so as to selectively activate it. The mains input (1) is connected to a smart power management system (20) configured to detect the output current and the load demand, and to ensure the opening and closing of the switch (16). The smart power management system (20) consists of a microcontroller (22), a voltage sensor (24), a load sensor (26), and a switch driver (28). The smart power management system (20) is active throughout the control operation. To ensure this, the current coming from the rectifier is fed from a power supply (not shown) to a circuit board (not shown) on which the smart power management system is arranged. It supplies the circuit board with a low voltage of 5 volts. The voltage sensor (24), which detects the current outputting from the mains input (1), transmits the detected current to the microcontroller (22). The microcontroller (22) periodically compares the current coming from the voltage sensor (24) with the predetermined threshold value of 210 volts. If the incoming current is below the threshold value, the microcontroller (22) operates the switch driver (28) connected to it, causing the switch (16) in the circuit to close, and activates the auxiliary capacitor (14) to provide the necessary energy. When the incoming current rises above the threshold value, the microcontroller (22) periodically compares the current coming from the voltage sensor (24) with the predetermined threshold value. If the incoming current is above the threshold value, the microcontroller (22) operates the switch driver (28)connected to it, causing the switch (16) in the circuit to open, and deactivates the auxiliary capacitor (14). The main capacitor (12) is connected in series to a rectifier (2) that converts alternating current into direct current. The current passing through the rectifier (2) goes to a load (3). The demand created by the load (3) is detected by the load sensor (26) and transmitted to the microcontroller (22). The microcontroller (22) periodically compares the load demand coming from the load sensor (26) with the predetermined threshold value of 20 watts. If the load demand is above the threshold value, the microcontroller (22) operates the switch driver (28) connected to it, causing the switch (16) in the circuit to close, and activates the auxiliary capacitor (14) to provide the necessary energy. The demand created by the load (3) is periodically detected by the load sensor (26) and transmitted to the microcontroller (22). The microcontroller (22) periodically compares the load demand coming from the load sensor (26) with the predetermined threshold value. If the load demand is below the threshold value, a standby state occurs, and the microcontroller (22) operates the switch driver (28) connected to it, causing the switch (16) in the circuit to open, and deactivates the auxiliary capacitor (14).

[0022] REFERENCE NUMBERS

[0023] 1 Mains input

[0024] 2 Rectifier

[0025] 3 Load

[0026] 10 Adaptive load balancer module

[0027] 12 Main capacitor

[0028] 14 Auxiliary capacitor

[0029] 16 Switch

[0030] 20 Smart power management system

[0031] 22 Microcontroller

[0032] 24 Voltage sensor

[0033] 26 Load sensor

[0034] 28 Switch driver

Claims

CLAIMS1- A power management circuit for a cooking appliance comprising a mains input (1); a main capacitor (12) to which the mains input (1) is connected such that it transmits electricity as alternating current; a rectifier (2) to which the main capacitor (12) is connected in series; a load (3) to which the rectifier (2) supplies direct current; a load sensor (26) connected to the input of the load (3) such that it controls the load state, characterized in that an auxiliary capacitor (14) is connected in parallel to the main capacitor (12) so as to form an adaptive load balancer module (10), and a switch (16) connected such that it selectively activates the auxiliary capacitor (14); a switch driver (28) that opens the switch (16) in a standby state where there is no load demand and closes the switch (16) when there is a load demand; and a microcontroller (22) that operates the switch driver (28) to which it is connected such that it closes and opens the switch according to the load demand transmitted by the load sensor (26).2- A power management circuit for a cooking appliance according to claim 1, wherein a voltage sensor (24) is connected to the mains input (1) and reporting the alternating current value coming from the mains to the microcontroller (22), and is configured such that if the current transmitted by the voltage sensor (24) to the microcontroller (22) is below a predetermined threshold value, it causes the switch driver (28) to close the switch (16).3- A power management circuit for a cooking appliance according to any one of the preceding claims, wherein the microcontroller (22) is configured to cause the switch driver (28) to open the switch (16) when the predetermined threshold value is exceeded.4- The power management circuit for a cooking appliance according to any one of the preceding claims, wherein the predetermined threshold value is at least 210 volts.5- The power management circuit for a cooking appliance according to any one of the preceding claims, wherein the load demand created by the load (3) is at least 20 watts in order for the switch driver (28) to be operated such that it closes the switch (16).6- The power management circuit for a cooking appliance according to claim 5, wherein the switch driver (28) is configured such that it opens the switch (16) in the event the load demand drops below 20 watts.7- The power management circuit for a cooking appliance according to any one of the preceding claims, wherein the switch (16) is connected in series to the auxiliary capacitor (14).8- The power management circuit for a cooking appliance according to any one of the preceding claims, wherein the voltage of the mains input (1 ) is 110-220 volts.

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