Real-time CPU Load Current Detection Circuit
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Solution Overview
Problem
Conventional load current detecting circuits for CPUs suffer from inaccuracy, which affects the control of rotational speed for cooling fans and heat dissipation efficiency.
Innovation Solution
A real-time load current detecting circuit comprising a power supply circuit, a delay circuit with a resistor and capacitor, a current sensing circuit with an operational amplifier, and a current feedback circuit with a feedback current source and resistor, allowing for accurate monitoring and detection of current without inaccuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a resistor is employed for monitoring current, then the current can be detected, but the detection accuracy is poor
Solution Approach 1:
The patent introduces an operational amplifier as an intermediary device between the current-carrying path and the measurement system. The op-amp converts the small voltage drop across the sensing resistor into a measurable voltage signal, enabling accurate current detection without significantly affecting the original current flow. This mediator approach resolves the contradiction by providing both detection capability and measurement precision.
Solution Approach 2:
The patent replaces the direct mechanical/electrical measurement method (measuring voltage drop across a resistor) with an electronic signal amplification method. By using the operational amplifier to amplify the sensing signal, the system achieves higher measurement precision while maintaining detection reliability, effectively substituting a simple resistive measurement with an enhanced electronic measurement system.
2Productivity
If PWM signals are used to detect current variation, then real-time control can be achieved, but detection accuracy remains insufficient
Solution Approach 1:
The patent applies preliminary action by using the operational amplifier to pre-process and amplify the current sensing signal before it is used for PWM control. This preliminary signal conditioning ensures that the control system receives an accurate, high-quality signal, thereby maintaining both real-time control capability and measurement precision simultaneously.
Solution Approach 2:
The patent implements a feedback mechanism where the amplified current signal is continuously fed back to the control system. This feedback loop enables real-time adjustment of the PWM duty cycle based on actual current conditions, achieving both real-time control and accurate current measurement by constantly monitoring and adjusting based on precise feedback information.
3Device complexity
If conventional detection circuits are used, then the system structure is simple, but the heat dissipation control is inaccurate
Solution Approach 1:
The operational amplifier serves as an intermediary that bridges the simple circuit structure and accurate temperature control. By adding this single intermediary component, the system achieves precise current measurement capability without significantly increasing overall circuit complexity, thereby enabling accurate heat dissipation control while maintaining structural simplicity.
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 precise current monitoring and detection, improving the accuracy of cooling fan control and heat dissipation efficiency by eliminating inaccuracy in current measurement.
Implementation Method 1
The feedback current source is adapted for mirroring a current sensed by the current sensing circuit
Data Source
AI summary
A real-time load current detecting circuit composed of a power supply circuit, a delay circuit, a current sensing circuit, and a current feedback circuit. The power supply circuit is adapted for providing the CPU with a power source. The delay circuit includes a resistor and a capacitor, connected to the power supply circuit. The current sensing circuit includes a comparison circuit connected to the delay and power supply circuits. The current feedback circuit includes a feedback current source and a resistor, connected to the current sensing circuit. The feedback current source is adapted for mirroring a current sensed by the current sensing circuit. In light of this, the current can be accurately monitored and detected and there is hardly inaccuracy for the detection of the current.