Thermistor Positioning in Printer Power Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multifunctional printing apparatuses with increased functionality and speed tend to generate more heat, leading to higher temperatures in the power supply unit, which can result in failures if not properly managed.
Innovation Solution
The thermistor is positioned farther from the input terminal than the smoothing capacitor in the power supply unit, allowing for quicker detection of temperature changes and reducing the likelihood of failures due to high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the thermistor is located closer to the input terminal than the smoothing capacitor, then the temperature detection is simpler and the detection response time is shorter, but the detection accuracy of high temperature changes in the power supply unit is reduced
Solution Approach 1:
The smoothing capacitor serves as an intermediary element between the input terminal and the thermistor. By positioning the thermistor on the output side of the smoothing capacitor rather than directly near the input terminal, the capacitor acts as a thermal buffer that allows the thermistor to detect actual high temperature changes in the power supply unit more accurately, while still maintaining acceptable response time characteristics.
2Volume of moving object
If the power supply unit is downsized to reduce the printing apparatus size, then the printing apparatus becomes more compact, but the heat release efficiency of the power supply unit is reduced and temperature increases
Solution Approach 1:
The thermistor is pre-positioned at a specific location on the output side of the smoothing capacitor, enabling early detection of temperature rises before they reach critical levels. This preliminary detection allows the control system to take preventive actions, such as reducing power consumption or activating cooling mechanisms, thereby managing heat in compact power supply units without requiring additional thermal management hardware.
3Productivity
If the printing apparatus has more functionality and higher printing speed, then the productivity is improved, but the power consumption and heat generation increase
Solution Approach 1:
The thermistor provides continuous temperature feedback to the control system, enabling real-time monitoring of power supply unit thermal conditions. This feedback mechanism allows the system to dynamically adjust power consumption based on temperature levels, ensuring that high-speed printing operations can be sustained without causing dangerous temperature rises, thus maintaining productivity while managing energy loss.
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
This configuration enables efficient detection of temperature changes in the power supply unit, reducing the duration of high temperatures and minimizing the risk of failures, even in downsized units with increased heat generation.
Implementation Method 1
a thermistor TM located farther from the input terminal Tn1 than a smoothing capacitor HC
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A printing apparatus that has a plurality of functions including a printing function of forming an image on a medium and is capable of executing printing with resolution of 300 dpi or more includes a plurality of operating units including a printing unit that forms an image on a medium; and a pow0065r supply unit that supplies power to the plurality of operating units. The power supply unit includes a substrate, an input terminal that receives an alternating voltage from a power cable electrically connected to an alternating power supply, a smoothing capacitor that smooths the alternating voltage input from the input terminal, a thermistor that detects a temperature, and a comparator that compares a signal output from the thermistor with a standard signal and outputs a notification signal. The input terminal, the smoothing capacitor, the thermistor, and the comparator are mounted on the substrate. The supply of power from the power supply unit is stopped based on the state of the notification signal. A gap between the input terminal and the thermistor is longer than a gap between the input terminal and the smoothing capacitor.