PCB-Mounted Rotary Switch Using Potentiometer Detent Detection
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Solution Overview
Problem
Existing electronic rotary switches often require numerous electromechanical components or complex sensors and evaluation circuits, making them mechanically complex and costly to produce, and they are not easily integratable onto a circuit board without wiring.
Innovation Solution
An electronic rotary switch design featuring a potentiometer with a rotatable sliding contact and latching elements, where the actuating element is connected in a rotationally fixed manner to the sliding contact, allowing for torque-based position detection and elimination of mechanical contact sets, with a control circuit measuring variable resistance to determine detent positions and provide a rotary switch position signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional electromechanical rotary switches with contact sets are used, then reliable switching states are achieved, but the mechanical complexity and number of components increase significantly
Solution Approach 1:
The patent removes the contact sets from the rotary switch mechanism, extracting the mechanical switching function and replacing it with an electronic sensing approach using a potentiometer and evaluation circuit, thereby reducing mechanical complexity while maintaining reliable position detection
Solution Approach 2:
The patent replaces the electromechanical contact-based switching system with an electronic system that uses a potentiometer to detect rotational position and an evaluation circuit to determine switching states, substituting mechanical contact sets with electronic sensing and processing components
2Measurement precision
If optical encoders or complex sensors are used for position detection, then precise rotary position detection is achieved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent employs a potentiometer, which is a simple, inexpensive, and widely available component, rather than expensive optical encoders or complex magnetic sensors. The potentiometer provides sufficient position detection precision for the application while being cost-effective and easy to manufacture
Solution Approach 2:
The potentiometer inherently provides both the sensing function and the positional information through its variable resistance characteristic, eliminating the need for separate complex sensor systems and evaluation circuits required by optical or magnetic encoders
3Reliability
If numerous electromechanical components are used in the rotary switch, then reliable switching functionality is achieved, but the ease of manufacture and production speed decrease
Solution Approach 1:
The patent combines the rotary actuator, potentiometer mounting, and position detection functions into a single integrated assembly that can be mounted directly on a circuit board, reducing the number of separate components and simplifying the manufacturing and assembly process
Solution Approach 2:
The rotary actuator with integrated potentiometer serves multiple functions: it provides the mechanical rotation interface, mounts the potentiometer for position sensing, and integrates directly with the circuit board, eliminating the need for separate wiring and mounting operations
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 results in a simple, cost-effective, and quickly producible electronic rotary switch that can be directly mounted on a circuit board, reducing mechanical complexity and preventing unintentional adjustments, while ensuring secure operation and limiting unauthorized access.
Implementation Method 1
a control circuit which is configured to measure a variable resistance of the potentiometer as a function of the locking position and to determine the respective locking position based on resistance value specifications
Data Source
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AI summary
The invention relates to an electronic rotary switch comprising a printed circuit board (10), a potentiometer (11) mounted on the printed circuit board (10) with a rotatable sliding contact (15), wherein the sliding contact (15) comprises a receiving element (17) designed for the rotationally fixed reception of an actuating element (16), wherein the printed circuit board (10) has a through-hole (19) through which the actuating element (16) and/or the receiving element (17) is guided, and wherein the actuating element (16) is rotationally fixedly connected to the receiving element (17) of the sliding contact (15), wherein the actuating element (16) comprises at least one detent element (20) on its circumference at the level of the printed circuit board (10), and the printed circuit board (10) has a plurality of detent recesses (21) in the region of the through-hole (19) which are configured as follows:that when the actuating element (16) is rotated, the at least one detent element (20) of the actuating element (16) engages in at least one of the detent recesses (21) of the circuit board (10) in a detent position, and a control circuit is configured to measure a variable resistance of the potentiometer (11) as a function of the detent position and, based on resistance value specifications for each of the detent positions, to determine the respective detent position and provide it as a rotary switch position signal. Furthermore, the invention relates to an instantaneous water heater with such a rotary switch.