Timing Controlled AC to DC Converter for Implantable Devices
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Solution Overview
Problem
Existing power management units in implantable biomedical devices are not power efficient due to the limited power availability from weak inductive coupling with external time varying magnetic sources, and existing solutions like Buck converters and switchable capacitor converters are not suitable for neuro-prosthetic and biomedical implant applications due to space constraints.
Innovation Solution
A timing controlled AC to DC converter that switchably couples a time varying input signal to a load circuit for controlled periods, using an integrator to generate a threshold signal and a switch to control the coupling, thereby achieving high conversion efficiency and minimizing power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a linear regulator is used to convert higher DC voltage to lower supply voltage for digital circuits, then voltage regulation is achieved, but power efficiency deteriorates with power loss up to 40%
Solution Approach 1:
The patent changes the operating parameters of the converter by using timing control to adjust the duty cycle of the switch, optimizing the conversion process. The control circuit varies the switching timing based on the difference between output voltage and reference voltage, achieving efficient regulation without significant power loss.
Solution Approach 2:
The patent employs periodic switching action where the switch alternates between on and off states at high frequency. This periodic switching enables the converter to transfer energy in discrete packets from the AC source through the capacitor to the load, achieving both regulation and high efficiency by minimizing continuous power dissipation.
2Loss of energy
If Buck converters or switchable capacitor converters are used to improve power efficiency, then conversion efficiency is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent merges multiple functions into a single integrated circuit structure. The converter combines AC-to-DC conversion, voltage regulation, and switching control in one compact unit, eliminating the need for separate external components that would increase device complexity and space requirements.
Solution Approach 2:
The patent creates a universal converter circuit that can operate with varying AC input voltages and provide regulated DC output for different load requirements. The single circuit design handles both conversion and regulation functions universally, adapting to different operating conditions without requiring additional specialized components.
3Power
If the converter operates with continuous coupling to maximize power transfer, then power delivery is maximized, but power loss increases and efficiency decreases
Solution Approach 1:
The patent uses periodic switching to couple the capacitor to the load only during specific time intervals when it benefits power transfer. The switch operates periodically at high frequency, connecting the capacitor to the load for brief intervals and disconnecting otherwise, thereby delivering necessary power while minimizing continuous power loss.
Solution Approach 2:
The patent implements dynamic control where the switching timing and duration are continuously adjusted based on real-time voltage conditions. The control circuit dynamically modifies the duty cycle to match load requirements, maximizing power delivery during high-demand periods while minimizing power loss during low-demand periods.
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 timing controlled converter achieves high power efficiency by regulating the output voltage to a preselected reference value, significantly improving efficiency compared to conventional methods, with power savings of up to 40% compared to linear regulators.
Implementation Method 1
An integrator is arranged to integrate the difference between the output or load voltage and the preselected reference voltage to thereby generate a threshold or control signal
Implementation Method 2
A switch is arranged to switchably couple the time varying input signal to the load circuit for controlled periods of time
Implementation Method 3
timing controlled AC to DC converter which supplies a regulated output voltage to a load circuit
Data Source
AI summary
A timing controlled converter and method for converting a time varying input signal to a regulated DC output voltage for application to a load circuit. A feedback loop is employed as a control means for switchably coupling the time varying input signal to the load circuit for controlled periods of time in a manner so as to provide an average load voltage equal to a reference voltage. The duration of the controlled periods of time is a function of: the difference between the time varying input signal and the output voltage; and the integral of the difference between the output voltage and the reference voltage.