Current Transformer Backup Power for RTC and Controller Data Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In back-up power systems, such as gensets, the continuous operation of real-time clocks and microcontrollers during power outages is challenging due to the finite capacity of backup batteries, which can lead to data loss and require frequent maintenance or replacement.
Innovation Solution
A controller system that utilizes a current transformer to sense alternating current, convert it to direct current, and charge a capacitor to provide power to microcontrollers and real-time clocks through a secondary power supply, switching from primary to secondary power when the main supply fails, maintaining a stable voltage level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a back-up battery is used to power the clock and microcontroller during power outages, then the system can maintain operation during short interruptions, but the battery has finite capacity and requires frequent maintenance or replacement
Solution Approach 1:
The patent changes the energy storage parameter from a battery with finite chemical energy capacity to a capacitor that can be continuously recharged from harvested AC energy. This parameter change enables indefinite operation by transitioning from a depletable energy source to a renewable energy storage system.
Solution Approach 2:
The system harvests energy from the AC power lines themselves to recharge the capacitor, enabling the backup power system to sustain itself without external intervention or battery replacement. The AC energy serves the dual purpose of normal operation and recharging the backup storage.
2Loss of information
If a back-up battery is used to maintain power during outages, then critical data can be preserved, but the battery requires periodic replacement and offline maintenance
Solution Approach 1:
The patent replaces the expensive, long-lifecycle battery with a capacitor that can be continuously recharged. While capacitors have shorter inherent lifespans, the continuous recharging from harvested AC energy effectively extends operational life indefinitely, eliminating the need for periodic battery replacement and maintenance.
Solution Approach 2:
Instead of allowing the battery to deplete and requiring replacement, the system continuously recovers energy from the AC lines to recharge the capacitor, effectively discarding the limitation of finite battery capacity and recovering energy repeatedly for indefinite operation.
3Use of energy by moving object
If the capacitor voltage level differs from the microcontroller operating voltage, then power can be stored at optimal levels, but voltage conversion is required to power the microcontroller
Solution Approach 1:
The patent introduces a voltage conversion circuit as an intermediary between the capacitor and microcontroller. This mediator handles the voltage level mismatch, allowing the capacitor to charge at one voltage level while providing the appropriate voltage to the microcontroller, thus resolving the incompatibility without compromising either energy storage efficiency or device operation.
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
Ensures continuous operation of critical data saves and clock functions during power outages by extending the power supply duration and reducing the need for frequent battery maintenance, providing reliable backup power through energy harvesting.
Implementation Method 1
The circuitry is structured to sense an alternating current (AC) from a current transformer coupled to the controller. The circuitry is structured to convert the AC, sensed from the current transformer, to direct current (rectified output DC).
Implementation Method 2
The circuitry is structured to charge a capacitor to a first predetermined voltage level using the rectified output DC of the current transformer. The capacitor is coupled to the controller and to a secondary power supply structured to provide power to the microcontroller when a primary power supply ceases providing power.
Data Source
AI summary
A controller includes a microcontroller and a control circuit. The control circuit includes circuitry structured to sense an alternating current (AC) from a current transformer coupled to the controller, convert the AC to direct current (rectified output DC), charge a capacitor to a first predetermined voltage level using the rectified output DC of the current transformer, and switch from a primary power supply for the microcontroller to a secondary power supply that includes the capacitor. The control circuit includes circuitry structured to cause the capacitor of the secondary power supply to provide power, at a second voltage level, to a clock coupled to the microcontroller.