Input-Regulated DC to DC Converter for Power Scavenging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC to DC converters are inadequate for regulating input voltage and efficiently scavenging power in current loops, leading to excessive voltage drops, inefficient power utilization, and safety hazards, particularly in variable current environments like 4-20 mA loops used in industrial processes.
Innovation Solution
An input-regulated DC to DC converter that maintains a constant voltage drop across its input terminals, varying power consumption linearly with current, using a boost controller and shunt regulator to harvest excess power and store it in capacitors, while ensuring safety through isolation transformers and filtering, thereby controlling impedance and minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a typical DC to DC converter draws necessary power from input terminals to produce regulated voltage at output terminals, then the output voltage is regulated, but the voltage drop across input terminals becomes excessive
Solution Approach 1:
The patent implements a feedback circuit that detects the voltage at the input terminals and adjusts the switching duty cycle accordingly. When the input voltage drops below a threshold, the feedback circuit reduces the duty cycle to prevent excessive voltage drop, thereby maintaining both output regulation and input voltage stability
Solution Approach 2:
The converter dynamically adjusts its power consumption based on real-time input voltage conditions. The switching duty cycle is continuously modified in response to feedback signals, allowing the converter to adapt its power draw to prevent excessive voltage drop while maintaining output regulation
2Power
If a scavenging device draws power from a current loop, then power is harvested for additional loads, but the voltage drop interferes with current loop signaling
Solution Approach 1:
The feedback circuit monitors both the input voltage and the current loop conditions, adjusting the power harvesting rate to maintain voltage within acceptable ranges that do not interfere with 4-20 mA signaling, enabling simultaneous power harvesting and reliable communication
Solution Approach 2:
The converter changes its operating parameters (switching frequency, duty cycle) based on the detected current loop conditions, optimizing the balance between power harvesting efficiency and maintaining voltage levels compatible with analog signaling
3Reliability
If additional circuitry is added to regulate input voltage and limit voltage drop, then voltage regulation is improved, but the circuit complexity increases
Solution Approach 1:
The patent combines the voltage regulation function with the existing power conversion circuitry by using the feedback signal to modulate the switching duty cycle. This integrates regulation into the core converter operation without requiring separate regulation circuits, reducing overall complexity
Solution Approach 2:
The feedback circuit serves multiple functions: it regulates input voltage, prevents excessive voltage drop, and adapts power harvesting to current loop conditions. This multi-functionality eliminates the need for separate dedicated regulation circuits
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 effectively regulates input voltage, efficiently harvests power, and ensures operational safety by maintaining a stable voltage drop and impedance control, reducing noise and power wastage, and preventing energy backflow in fault conditions, thus enhancing the reliability and efficiency of power scavenging in current loops.
Implementation Method 1
these converters cyclically vary the periods of time during which an inductor accumulates and then releases electrical energy
Implementation Method 2
ensuring safety through isolation transformers
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of scavenging power in a circuit having a power source generating electric current includes connecting a power scavenging device having an input terminal pair and an output terminal pair to the circuit via the input terminal pair, dynamically regulating a voltage drop across the input terminal pair of the power scavenging device, harvesting electrical energy available at the regulated voltage drop from the electric current flowing through the first imputer terminal pair of the power scavenging device, and providing the harvested electrical energy at the output terminal pair of the power scavenging device.