Sleep Current Detection Circuit for Battery-Powered HVAC Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless HVAC systems face challenges with high manufacturing costs, limited battery lifespan, and increased maintenance due to the need for periodic battery replacements, as well as inefficiencies in power consumption and network communication protocols.
Innovation Solution
A method and circuit for detecting excessive sleep current draw in battery-powered devices using a MOSFET and transistor configuration, combined with energy-efficient data transmission techniques in mesh networks, which reduce power consumption and extend battery life by minimizing wake/sleep cycles and delegating address determination to routers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless HVAC devices use battery power to reduce installation complexity and cost, then ease of installation is improved, but battery lifespan is limited and requires periodic replacement
Solution Approach 1:
The system performs self-diagnosis of sleep current conditions and automatically triggers wake events when excessive current is detected, eliminating the need for manual intervention and enabling the device to monitor and respond to its own power consumption state
Solution Approach 2:
The sleep current detection circuit continuously monitors current consumption during sleep mode and provides feedback to the microcontroller, which then adjusts its wake/sleep behavior based on the detected conditions, creating a closed-loop power management system
2Use of energy by moving object
If the device enters sleep mode frequently to conserve energy, then power consumption is reduced, but reliability decreases due to potential missed detections
Solution Approach 1:
The sleep current detection circuit is activated before the device enters sleep mode to pre-assess current conditions, allowing the device to make informed decisions about entering sleep state and preventing missed detections by ensuring proper detection setup in advance
Solution Approach 2:
The detection circuit maintains continuous monitoring capability during sleep mode through the persistent conduction of the first transistor when voltage threshold is exceeded, ensuring uninterrupted detection functionality even when the microcontroller is in low-power state
3Reliability
If the device remains awake to ensure reliable detection, then reliability is improved, but power consumption increases
Solution Approach 1:
The detection function is segmented into a dedicated hardware circuit (first transistor, MOSFET, voltage threshold comparator) that operates independently of the microcontroller's sleep/wake cycles, allowing continuous detection monitoring with minimal power consumption while maintaining reliability
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 reduces manufacturing costs, increases device reliability, and extends battery life by efficiently managing power usage and optimizing network communication, thereby enhancing the overall performance and market competitiveness of wireless HVAC systems.
Implementation Method 1
measuring a voltage drop across a MOSFET device coupled in a forward-conducting orientation in series between the battery and the microcontroller
Implementation Method 2
causing a transistor to conduct when the voltage drop exceeds a predetermined threshold to generate a first trigger signal
Implementation Method 3
a second transistor, the base terminal thereof coupled to the collector of the first transistor, the collector terminal thereof coupled to an R-C filter
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
HVAC components having improved efficiency are described. In one embodiment, excessive sleep current draw in a battery-powered device having a microcontroller is detected by measuring a voltage drop across a MOSFET device coupled in a forward-conducting orientation in series between the battery and the microcontroller, causing a transistor to conduct when the voltage drop exceeds a predetermined threshold to generate a first trigger signal, integrating the first trigger signal to generate a second trigger signal, and generating an interrupt to the microcontroller. In another embodiment, a battery-saving method of operating an HVAC component includes maintaining the HVAC device in the sleep mode, receiving a user input to wake the device, transmitting a data request and returning the HVAC component to the sleep mode, waking up the HVAC device to poll an adjacent network node storing a cached response, displaying the response, and returning the HVAC device to sleep.