Sensor-Triggered Power On/Off Circuit With Capacitive Shutdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power on/off circuits fail to disconnect properly when a sensor is not reset, leading to continuous power supply, high standby current, and reduced battery usage time.
Innovation Solution
A power on/off circuit design that includes a sensor, a first switch element, and a capacitor, where the capacitor controls the on-off state of the first switch element based on the control signal from the sensor, preventing continuous conduction even if the sensor is not reset.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a sensor is used as a starting element to control power on/off, then power consumption is reduced during idle periods, but the circuit cannot be disconnected properly when the sensor is not reset, leading to high standby current
Solution Approach 1:
The patent introduces a capacitor as an intermediary element between the sensor and the switch. The capacitor couples the sensor output to the switch control terminal, allowing the sensor to control the switch while the capacitor's discharge characteristic ensures the switch turns off even when the sensor fails to reset, thus resolving the contradiction between energy saving and shutdown reliability
Solution Approach 2:
The capacitor is charged during the power-on state and provides a discharge path when the sensor fails to reset. This beforehand cushioning ensures that the switch control terminal maintains the off-state voltage level even when the sensor continuously outputs the power-on signal, preventing continuous conduction and ensuring reliable shutdown
2Ease of operation
If the sensor continuously outputs the power-on signal when not reset, then the circuit remains conductive, but this leads to large standby current and reduced battery usage time
Solution Approach 1:
The capacitor acts as a mediator that decouples the sensor's continuous power-on signal from the switch control terminal. The capacitor's discharge characteristic ensures that the switch turns off after a certain period, allowing easy power-on control while preventing continuous conduction that would drain the battery
Solution Approach 2:
The capacitor creates a periodic discharge pattern at the switch control terminal. When the sensor outputs a continuous power-on signal, the capacitor charges and then discharges through the switch, creating a periodic on-off action rather than continuous conduction, thereby reducing standby current and extending battery life
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 proposed solution effectively prevents the power on/off circuit from remaining continuously conductive, ensuring proper shutdown and reducing standby current, thereby extending battery life.
Implementation Method 1
a capacitor connected between a third end of the first switch element and the sensor, the capacitor being configured to control an on-off of the first switch element based on the first control signal
Data Source
AI summary
A power on/off circuit includes: a sensor for generating a corresponding first control signal based on a user operation; a first switch element, a first end of the first switch element being connected to a voltage input end, a second end of the first switch element being connected to a voltage output end, the voltage input end being connected to a power supply voltage; and a capacitor connected between a third end of the first switch element and the sensor, the capacitor controlling an on-off of the first switch element based on the first control signal.