You may have noticed that the implementation methods of magnetic control switches are diverse, but they are mainly based on two core components:
Pneumocouple: A small glass tube filled with inert gas and containing metal spring plates inside. When an external magnet approaches, the spring plates are magnetized and attracted, connecting the circuit; when the magnet moves away, the spring plates separate and the circuit is disconnected. It is commonly used in water level detection of豆浆 machines and door control of refrigerators.
Hall element： A semiconductor magnetic-sensitive component. It does not directly “attract”， but senses changes in the magnetic field and outputs an electrical signal. This method is more sensitive and can achieve precise displacement or angle measurement， and is often used for position encoding of non-contact knobs.
A crucial reminder: To ensure safety and proper operation, household magnetic control switches must never be directly connected to the 220V high-voltage power lines. They are usually used as signal detection devices, outputting a “on/off” weak electrical signal to the main control board of the appliance, which in turn controls the compressor, heating tubes, and other high-power components.
?? Maintenance and Repair Tips
If you encounter situations where an electrical appliance fails to start due to issues with the door or cover, or where the indicator lights do not light up, consider the following:
1. Initial Inspection: First, ensure that the magnet (usually installed on the movable door or cover) is aligned with the switch body (installed on the fixed frame) and that the distance is within a few millimeters of the effective range. Also, check if the magnet has fallen off.
2. Professional Testing: If you suspect a fault with the switch itself, you can use the resistance setting on a multimeter to test. When the magnet is close and far away, measure the on-off state of the switch terminals to see if there is any change. If it is always off or always on, it may be damaged.
3. Replacement Principles: If replacement is necessary, try to use the same model parts from the original factory. If not available, you must confirm that the new part’s type (normally open/closed), electrical parameters (voltage, current), size and installation method are consistent with the original part.
Comparison with other switches
Compared with mechanical microswitches: The greatest advantage of magnetic control switches is non-contact. It avoids wear caused by repeated pressing of mechanical keys, has a longer lifespan, and is not affected by oil stains or moisture (depending on the protection level), and is highly reliable.
Different types of magnetic control switches:
Pendulum-type: Simple structure, low cost, but the reaction distance is short (usually within 10mm), and the mechanical spring has a service life.
Hall-type: No contacts, extremely long lifespan, can detect weak magnetic field changes, suitable for scenarios requiring precise detection of position or angle, but the circuit is relatively complex.
Post time: Dec-17-2025