Start-up Circuit Element for Controlled Electrical Supply
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Solution Overview
Problem
Existing electrical supply systems face challenges in reliable start-up due to manufacturing tolerances and slow power build-up, often requiring additional components or increased current consumption, which can lead to inefficiencies and wasteful power usage during normal operation.
Innovation Solution
A start-up circuit element utilizing Pmos FETs and Nmos FETs with a current mirror configuration, along with diodes and resistors, ensures reliable start-up with minimal additional components and reduces residual current consumption by leveraging leakage currents and feedback mechanisms to manage power usage effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional start-up circuit elements are used to ensure reliable start-up, then start-up reliability is improved, but additional components and increased current consumption are required
Solution Approach 1:
The start-up circuit element is integrated within the electrical supply circuit itself, merging the start-up function with the main circuit components. The first and second transistors are part of the same circuit family as the output transistors, eliminating the need for separate external start-up circuit components while ensuring reliable start-up through the embedded start-up path.
Solution Approach 2:
The transistors in the electrical supply circuit serve dual functions: they act as both the main output transistors for normal operation and as the start-up circuit elements. The first transistor functions as both an output transistor and a start-up device, while the second transistor serves similarly, allowing the same components to fulfill multiple roles without requiring additional dedicated start-up components.
2Reliability
If conventional start-up circuit elements are used to ensure reliable start-up, then start-up reliability is improved, but current consumption increases during normal operation
Solution Approach 1:
The start-up circuit exhibits dynamic behavior where the transistors are actively conducting during start-up to ensure reliable power-on sequence, but automatically transition to a non-conducting or minimal conduction state during normal operation. The third transistor acts as a dynamic switch that is conductive only during the start-up phase, enabling the start-up path to be active when needed and inactive during quiescent operation, thus eliminating residual current consumption.
Solution Approach 2:
The start-up circuit operates in a time-dependent manner where the start-up transistors are activated only during the initial power-on period and automatically deactivate once the electrical supply reaches its normal operating state. This periodic activation ensures reliable start-up while minimizing energy consumption during the extended normal operation phase, as the start-up circuit remains inactive except for brief transitions.
3Manufacturing precision
If manufacturing tolerances are considered, then production variability increases, but start-up reliability decreases
Solution Approach 1:
The circuit incorporates feedback mechanisms where the output voltage and current states are monitored and fed back to control the start-up transistors. The third transistor's gate is controlled by a voltage that depends on the output voltage and current, creating a feedback loop that automatically adjusts the start-up path activation based on actual circuit conditions. This feedback ensures reliable start-up even with manufacturing variations by adapting to the actual component characteristics rather than relying on fixed threshold values.
Solution Approach 2:
The start-up circuit utilizes changes in voltage and current parameters during the power-on sequence to ensure reliable operation. The gate voltage of the third transistor varies dynamically based on the output voltage and current states, allowing the circuit to adapt to manufacturing tolerances. By using parameter changes rather than fixed threshold switching, the circuit maintains robust start-up performance across production variations.
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 ensures reliable start-up of electrical supply systems with reduced power consumption during the quiescent state, minimizing wasteful power usage and maintaining efficient operation across varying temperatures and manufacturing variances.
Implementation Method 1
leveraging leakage currents and feedback mechanisms to manage power usage effectively
Data Source
AI summary
Electrical supply apparatus comprising a start-up circuit element coupled to an output element for ensuring reliable start-up when first connected to a source of power. The start-up circuit element comprises first and second branches with current mirror coupling therebetween. The first branch comprises first and second transistors of opposite polarities for connection in series between the source of power and ground and a leakage path to ground in parallel with the second transistor for start-up current for the first transistor of the first branch in response to application of voltage from the source of power. The current mirror coupling between the first and second branches responds to start-up of the first transistor of the first branch to start up a first transistor of the second branch and provide start-up current to the output element. The second branch may comprise a control element connected to turn off the second transistor of the first branch on start up of the output element and turn off the first transistors. Alternatively, the start-up circuit may have elements common with the output circuit and remain conductive after the output circuit starts.