Other Parts Discussed in Thread: HALL-HMI-ROCKER-EVM, DRV5032
Question: Can home appliances – specifically range hoods – use position sensors such as Inductive sensors for push-buttons, or Hall-effect sensors for rocker switches?
Answer: Yes, in many cases – including appliances - controls that have traditionally been supported by mechanical switches can indeed be implemented with inductive sensors or Hall-effect sensors. The remainder of this note provides two examples where these sensors are used for vent hood controls.
Use case #1: Push-button control of fan/ventilation and light control.
The image below shows a range hood control cluster with five push-buttons that control the exhaust fan speed and the under-hood lighting.
These push-buttons can be implemented with inductive sensors. What would be the best way to do this?
Please see the tables below for device recommendations and links to application notes and other documents.
Recommended Products
| Device | Data Sheet | Description | System-level Benefits |
| LDC3114 | LDC3114.pdf | 4-channel inductance-to-digital converter for low-power proximity and touch-button sensing |
Device analog & digital features coupled with internal algorithms The raw data output supports estimation of the button-press force, |
| LDC2114.pdf | 2 or 4- Inductive Touch Solution for Low-Power HMI Button Applications |
Device analog & digital features coupled with internal algorithms make this a best-in-class device for push-button applications. The |
Related Documents
| Title | Description | Summary |
| Replacing Mechanical Switches with Inductive Sensors | App brief | A brief survey of the parameters and features that make LDCs a great way to implement push-button functions for many applications. |
| Design Considerations for Inductive Touch Buttons for the Human-to-Machine Interface |
App brief | A brief survey of the major care-abouts for inductive touch buttons. |
| Evaluation module for inductive touch and magnetic dial contactless user-interface design |
Application EVM with GUI and user’s guide |
This EVM features eight push-buttons and a dial based on Hall sensor technology. The EVM + GUI provide a convenient platform for experimentation and the user’s guide provides details on the EVM design and functions. |
Use case #2: Rocker switch control of fan/ventilation and light control.
One possible goal of a range hood design is to have hidden fan and light controls because push-buttons on the front of the unit may be considered undesirable.
If the controls are located on the underside of the range hood, it may be difficult to navigate and control push-buttons by touch alone.
In this case, rocker switches may be the best choice, and these can be implemented using Hall-effect devices.
Please see the tables below for device recommendations and links to application notes and other documents.
| Device | Data Sheet | Description | System-level Benefits |
| DRV5033FADBZ | DRV5033.pdf | Digital-Omnipolar-Switch Hall Effect Sensor BOP Max/BRP Min = ±6.8mT/±0.5mT |
The various sensitivity levels allow for many magnet sizes and |
| DRV5033JDBZ | DRV5033.pdf |
Digital-Omnipolar-Switch Hall Effect Sensor |
|
| DRV5032 | DRV5032.pdf |
Digital-Omnipolar-Switch Hall Effect Sensor |
Related Documents
| Title | Description | Summary |
| Evaluation module for human machine interface (HMI) rocker switch using Hall-effect switches |
HALL-HMI-ROCKER-EVM and user’s guide |
A brief survey of the parameters and features that make LDCs a great way to implement push-button functions for many applications. |
Additional Tools and Resources
- DRV5032-SOLAR-EVM - Great for getting started with the DRV5032
- TI Precision Labs Training Videos
- Sensing Magnetic Fields In-Plane Versus Out-of-Plane
- Inductive sensing FAQ - Frequently asked questions
- Inductive Sensing Design Calculator Tool
