Resistive Ice Level Probe with LED Illumination for Reliable Detection
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Solution Overview
Problem
Existing ice level probes in ice maker machines face issues such as failure to start or stop production correctly when the bin is full or empty, sensitivity changes due to calcium deposits, electromagnetic interference, and temperature-dependent sensitivity, leading to inconsistent ice production and high maintenance costs.
Innovation Solution
A resistive-type ice level probe heated through the Joule effect, integrated with an LED light emitter and embedded in a thermally conductive resin, which distinguishes between cold air and ice through temperature thresholds and provides visual indication, is designed to be durable and resistant to environmental changes and mechanical wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical probes are used to detect ice level, then detection capability is provided, but calcium deposits obscure the photodiodes and phototransistors over time, compromising operation and requiring recalibration
Solution Approach 1:
The patent replaces optical detection components (photodiodes, phototransistors) that are susceptible to calcium deposit obscuration with a thermal detection system using temperature sensors and controlled heating elements. This substitution eliminates the vulnerability to optical blockage while maintaining ice level detection capability through thermal conductivity differences between ice and air.
Solution Approach 2:
The patent employs simple, inexpensive temperature sensors and heating elements that are resistant to calcium deposits, replacing complex optical systems that require maintenance and recalibration. The thermal-based components are more durable and do not suffer from the same degradation issues as optical components.
2Measurement precision
If ultrasonic probes are used for ice level detection, then detection is provided, but condensation on the electronic transducer capsules decreases sensitivity
Solution Approach 1:
The patent replaces ultrasonic transducer capsules that are prone to condensation and sensitivity loss with thermal sensors and heating elements. The thermal system is not affected by condensation in the same way, as the controlled heating maintains temperature differentials that prevent condensation formation on the sensing elements.
3Stability of the object's composition
If capacitive probes are installed near metal parts for electromagnetic shielding, then stability is improved, but electromagnetic disturbance still changes sensitivity and production cost increases
Solution Approach 1:
The patent replaces capacitive probes that are inherently sensitive to electromagnetic disturbances with a thermal detection system using temperature sensors and heating elements. This thermal-based approach is immune to electromagnetic interference, eliminating the need for complex shielding and associated costs while maintaining stable operation.
4Measurement precision
If thermostatic bulb probes are used for ice level detection, then detection is provided, but sensitivity changes with weather conditions and reaction time is long due to high thermal inertia
Solution Approach 1:
The patent divides the probe into separate functional components: a small heating element and a temperature sensor positioned close together. This segmentation allows the heating element to provide localized thermal energy while the sensor rapidly detects temperature changes, reducing the overall thermal inertia and improving reaction time compared to large thermostatic bulbs.
Solution Approach 2:
The patent changes the thermal parameters of the probe by using a controlled heating system with a small thermal mass, as opposed to the large thermal mass of thermostatic bulbs. This allows the system to rapidly heat and cool in response to ice level changes, significantly reducing reaction time while maintaining detection accuracy.
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 probe ensures reliable ice production with fast reaction times, reduced maintenance needs, and visual ice level indication, avoiding recalibration and sensitivity issues, while being cost-effective and simple to integrate.
Implementation Method 1
A resistive-type ice level probe heated through the Joule effect
Implementation Method 2
integrated with an LED light emitter and embedded in a thermally conductive resin
Implementation Method 3
embedded in a thermally conductive resin
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
Ice level probe (4) for an ice maker machine comprising an evaporator of a refrigerating unit and an ice-collecting bin (3) in which a said ice level probe (4) is positioned, comprising at least one temperature sensor (5) connectable to an electronic control card (7) that comprises Joule effect heating means (6) connectable to said electronic control card (7), wherein said heating means (6) comprise at least one electrical resistance (6'), the thermal power that can be delivered by said heating means (6) being calibrated so as to be sufficient to maintain the probe (4) in thermal equilibrium in free air but insufficient to maintain the probe in thermal equilibrium with solid or melting ice, characterized in that said heating means (6) comprise at least one LED (6") and characterized also by the fact of comprising a tubular casing (8) containing a resin based embedding mean (9, 10) with high thermal conductivity, in which said heating means (6) and said temperature sensor (5) are embedded, said embedding means (9) being transparent at least around said LED (6") and said tubular casing (8) being made from a material suitable for diffusion of the light generated by said at least one LED (6") that advantageously performs the dual function of heat sink and illuminator of the ice, so as to provide the user with a precious visual indication of the presence of ice in the bin (3) at the desired level reached.