Air Conditioner Fixed-Resistor Sensor for Subzero Compressor Operation
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Solution Overview
Problem
Existing air conditioners cannot operate below 15°C, limiting their ability to provide a freezing function in small confined spaces, as the compressor stops functioning at ambient temperatures lower than 15°C due to the resistance characteristics of indoor ambient temperature-based NTC thermistors.
Innovation Solution
A compressor control system that uses a first temperature sensor electrically connected to a fixed-value resistor, ensuring a constant resistance, allowing the compressor to operate normally at temperatures below 0°C by maintaining a high-level signal and keeping the power voltage input connected, and includes additional temperature sensors for coil and fin temperatures with similar fixed-value resistors to ensure continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an indoor ambient temperature-based NTC thermistor is used to control the compressor, then the compressor can automatically start or stop based on temperature, but the compressor stops working when the temperature drops below 15°C, preventing freezing function
Solution Approach 1:
The patent changes the resistance parameter of the temperature sensor from variable (NTC thermistor) to constant (fixed-value resistor). This parameter change allows the sensor to maintain a constant high-level signal across all temperatures, preventing the compressor from stopping at low temperatures and enabling freezing function while maintaining automatic control capability
Solution Approach 2:
Instead of using a sensor whose resistance changes with temperature (NTC thermistor), the patent inverts the approach by using a fixed-value resistor that maintains constant resistance regardless of temperature. This inversion of the resistance-temperature relationship solves the problem of compressor shutdown at low temperatures
2Temperature
If a common air conditioner is transformed to provide freezing function, then subzero temperature refrigeration can be achieved, but the existing NTC thermistor resistance characteristics prevent operation below 15°C
Solution Approach 1:
The patent changes the electrical resistance parameter of the temperature sensor from temperature-dependent (NTC) to temperature-independent (fixed-value). This ensures the sensor always outputs a high-level signal, maintaining reliable compressor operation across the extended temperature range including subzero conditions
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
Enables the air conditioner to maintain refrigeration below 0°C, transforming it into a freezer capable of reaching −20°C, thus extending the temperature adjustment range and allowing use as a freezer in small spaces without the need for a separate freezer.
Implementation Method 1
the main board is electrically connected to an indoor ambient temperature-based negative temperature coefficient (NTC) thermistor. The indoor ambient temperature-based NTC thermistor transmits, based on a specified operating state, a resistance that varies with a detected indoor ambient temperature
Implementation Method 2
A compressor compresses a gas refrigerant into a high-temperature and high-pressure gas refrigerant
Implementation Method 3
The liquid refrigerant enters an evaporator through a capillary tube to absorb heat in indoor air and is then vaporized into the gas refrigerant
Implementation Method 4
The liquid refrigerant enters an evaporator through a capillary tube
Data Source
AI summary
Disclosed are a compressor control system and an air conditioner for wide-range temperature adjustment. The control system includes a power supply, a compressor, a main board, and a first temperature sensor. The power supply is configured to generate a power input voltage. A power voltage input circuit is disposed between the compressor and the power supply. The main board is electrically connected to the power voltage input circuit. During operation, the main board is configured to control connection and disconnection of the power voltage input circuit. The first temperature sensor is configured to detect an indoor temperature, the first temperature sensor is electrically connected to the main board and transmits an electrical signal to the main board, and the first temperature sensor is electrically connected to a first fixed-value resistor.