H-Bridge Power Transistor Control Circuit
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Solution Overview
Problem
Existing power electronic component control circuits require modifications in resistivity and capacitance values for each new application or change in operating parameters, which is inefficient and can lead to potential damage due to high current peaks during switching.
Innovation Solution
A control circuit and method using an H-bridge configuration with MOS transistors and variable resistance current generators, controlled by a digital control device, to precisely manage the voltage between the gate and emitter of power transistors, allowing for adaptive control without component changes and minimizing energy dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If RC circuits with fixed resistivity and capacitance values are used for controlling power transistors, then the circuit structure is simple, but the circuit cannot adapt to different applications or operating parameter changes without modifying component values
Solution Approach 1:
The patent applies the dynamics principle by replacing fixed RC circuits with an H-bridge circuit that can dynamically adjust the gate-emitter voltage through controlled switching of MOS transistors. The circuit transitions from static component values to dynamic control, allowing adaptation to different applications by modifying control signals rather than physical components.
Solution Approach 2:
The patent implements parameter changes by using variable resistance current generators that can alter the current amplitude and duration flowing through the gate-emitter circuit. This allows the effective resistance and capacitance parameters to be changed dynamically through control signals, enabling adaptation to different power transistor switching requirements without physical component modification.
2Reliability
If high current peaks are used during switching to ensure reliable transistor activation, then the switching reliability is improved, but the risk of damaging the power transistors increases
Solution Approach 1:
The patent applies partial action by controlling the current flow to be sufficient but not excessive. The H-bridge circuit with variable resistance current generators delivers precisely the amount of current needed for reliable switching without the harmful excessive current peaks. The control logic ensures the current is applied in optimal pulses that activate the transistor reliably while staying within safe limits.
Solution Approach 2:
The patent implements feedback through control logic that monitors the switching state and adjusts the current generator output accordingly. This feedback mechanism ensures that enough current is applied to guarantee reliable switching while preventing excessive current that could damage the transistor, thus resolving the contradiction between reliability and damage risk.
3Ease of manufacture
If traditional RC circuits are used for power transistor control, then the circuit design is straightforward, but energy dissipation is high and component lifespan is reduced
Solution Approach 1:
The patent applies the recovering principle by using capacitors in the H-bridge circuit to store and reuse energy during switching operations. Instead of dissipating energy as heat in traditional RC circuits, the capacitive elements recover energy from the gate-emitter circuit and make it available for subsequent switching events, significantly reducing overall energy dissipation while maintaining circuit design feasibility.
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
Enables efficient and adaptive control of power transistors across different applications, reducing the risk of damage from high current peaks and minimizing energy consumption by recovering energy through capacitors, thus extending component lifespan and reducing operational costs.
Implementation Method 1
a first capacitance (32) connected between the gate and the emitter of the power transistor (12)
Implementation Method 2
a first switch consisting of a first MOS transistor (34), a source (34S) of the first MOS transistor (34) being connected to a first node (52), a drain (34D) of the first MOS transistor (34) being connected to a second node (53)
Data Source
AI summary
The circuit (26) has a vertical branch (33A) including a MOS transistor (34) separated from a digitally controlled current generator (40) by a mid-point (32A) that is connected to an emitter electrode of a power transistor (12) e.g. Insulated gate bipolar transistor. A vertical branch (33B) has a MOS transistor (36) separated from a digitally controlled current generator (44) by a mid-point (32B) that is connected to a gate electrode of the transistor (12). The generators deliver supply currents directed according to two directions to supply the grid and emitter electrodes, respectively. Independent claims are also included for the following: (1) a method for piloting a control circuit (2) a control device for controlling a control circuit, comprising a piloting unit (3) an igniter comprising a control device.