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Parameters:
- Power supply voltage: Type-C interface DC-5V
- Output interface: 3.5mm interface
- Operating environment: -40°C to 85°C
Principle Description:
The touch key is divided into upper and lower layers. The upper layer comprises the main circuit and interface part of the key, while the lower layer serves as the magnet fixing base. The entire device employs a touch chip to detect capacitance changes induced by the metal ball. When a human body touches the metal ball, the capacitance change is transmitted through the lines to the relevant pins of the chip. The corresponding keying signal is then amplified and driven by the triode before being transmitted to the key interface. The logic of the entire device dictates that an effective keying signal corresponds to a low level, while a non-touch signal is at a 5V high level. This level format aligns with the operation of most radios. The lower layer features a strong magnet capable of adhering to any iron shell, thereby serving the purpose of fixing the electric key in place.
Instructions for Use:
The USB cable can be connected to a mobile phone charger or a computer. It's important to note that the USB must be powered by 5V; other voltages will damage the chip. Once powered on, the LED near the USB port will illuminate, indicating normal power supply. At this point, touching the left and right metal balls will cause the corresponding LED lights to illuminate. This indicates that the touch is valid, and the product is functioning normally. A short touch on the right button represents a point, while a long touch on the left button represents a stroke. price/$24