Refrigerator with selectively activable microprocessor for an inverter compressor
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Solution Overview
Problem
Conventional mechanical refrigerators with constant speed induction motors fail to reduce power consumption effectively, leading to inefficiencies in temperature control and increased energy usage.
Innovation Solution
A mechanical refrigerator design incorporating an inverter compressor driven by a BLDC motor, a microprocessor controlled by a power detection circuit connected to a thermostat, and a power circuit that maintains power supply status, allowing for variable speed operation and reduced standby power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a constant speed induction motor is used in a mechanical refrigerator, then the structure is simple and the price is low, but the power consumption cannot be reduced effectively
Solution Approach 1:
The patent applies dynamics by replacing the constant speed induction motor with an inverter compressor that uses a BLDC motor capable of variable speed operation. The microprocessor controls the motor speed dynamically based on temperature feedback from the thermostat, allowing the system to optimize power consumption while maintaining cooling effectiveness. This transforms the static, constant-speed system into a dynamic, adaptive system that adjusts to varying thermal loads.
2Reliability
If a microprocessor is always powered on to control the inverter compressor, then precise temperature control is achieved, but standby power consumption increases
Solution Approach 1:
The patent implements periodic action by designing the power detection circuit to selectively activate the microprocessor only when the thermostat switches on. When the thermostat is off (indicating temperature is within range), the microprocessor is deactivated to save power. When the thermostat switches on (indicating temperature deviation), the microprocessor is activated to restore proper temperature control. This periodic activation maintains reliability while significantly reducing standby power consumption.
Solution Approach 2:
The system applies self-service through the power detection circuit that automatically detects thermostat status and controls microprocessor power supply accordingly. The microprocessor itself is powered by the power circuit only when needed, creating a self-regulating power management system that responds to actual control requirements without continuous external power supply.
3Measurement precision
If expensive components like NTCs and relays are used for temperature control, then measurement precision improves, but production cost increases
Solution Approach 1:
The patent applies copying by using the thermostat's existing switching function to generate control signals for the microprocessor, eliminating the need for separate expensive temperature sensing components like NTCs. The thermostat's on/off status is detected by the power detection circuit and copied as a control signal to activate the microprocessor, which then performs precise temperature control algorithms. This approach achieves high measurement precision through software-based control while avoiding the cost of additional hardware sensors.
Solution Approach 2:
The thermostat is given a multi-functional role: it serves both as the traditional temperature control switch and as a trigger signal source for the microprocessor-based inverter control system. The power detection circuit utilizes the thermostat's switching action to simultaneously control both the compressor power supply and the microprocessor activation, eliminating the need for separate relays and expensive sensing components. This universal utilization of the thermostat reduces component count and production costs while maintaining or improving control precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables efficient temperature control with reduced power consumption, eliminates the need for expensive components like NTCs and relays, and simplifies the printed circuit board design, resulting in lower production costs and improved reliability.
Implementation Method 1
The power detection circuit outputs a set voltage when the thermostat is on, and may output 0 V when the thermostat is off
Implementation Method 2
a microprocessor to control a drive operation of the compressor, a power circuit to provide power to the microprocessor to drive the compressor
Implementation Method 3
an inverter compressor to compress a refrigerant
Data Source
Figure 1
Figure 2~3
AI summary
A refrigerator (1) including a main body (10) forming a storage space (12, 13); an inverter compressor (151) compressing a refrigerant; a microprocessor (42) controlling drive of the compressor (151); a thermostat (50), which is connected to a power supply (30) and switched on or switched off according to changes in a temperature of the storage space (12, 13); a power detection circuit (41), which is connected to the power supply (30) and the thermostat (50) electrically, and configured to switch on or off the microprocessor (42) according to a status of the thermostat (50); and a power circuit (43) connected to the power supply (30) and the microprocessor (42) and configured to supply power for driving the compressor (151) to the microprocessor (42).