Parameter Power Supply Voltage Type C interface DC 5VOutput Interface 3 5mm interfaceOperating Environment 40°C to 85°CPrinciple Description The touch key is divided into upper and lower layers the upper layer is the main circuit and interface part of the key and the lower layer is the magnet fixing base The whole machine uses a touch chip to sense the capacitance change from the metal ball After the human body touches the metal ball the change in capacitance is transmitted to the relevant pins of the chip through the line and the relevant keying signal is amplified and driven by the triode and finally transmitted to the At the key interface the logics of the whole machine is that the effective keying signal is low level and the non touch signal is 5V high level This level form matches the operation of most radios The lower layer is a strong magnet which can be sucked on any iron shell and play the role of fixing the electric key Instructions for Use The USB cable can be connected to a mobile phone charger or a computer Note that the USB must be powered by 5V and other voltages will burn the chip After the power is turned on the LED at the position of the USB port will light up indicating that the power supply is normal At this time if you touch the left and right metal balls you can see the LED light at the corresponding ball position At this time the touch is valid and the product function is normal The touch button on the right is for a short tim