Economical Frequency Adjustable Microphone Ultra-miniature FM Transmitter/Wireless Module | Инструменты

Economical Frequency Adjustable Microphone Ultra-miniature FM Transmitter/Wireless Module | Инструменты

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Waist buckle FM receiver

Economical frequency adjustable microphone, sensitivity adjustable subminiature patchFMEmitter：This module is an ultra micro FM wireless microphone module，The buyer needs to weld the power supply and antenna by himself。Turn on the power and place the module in the room to be monitored，FM radio can be used outside the room to receive and monitor the sound in the room。This module will generate frequency drift due to human induction，Suitable for listening，That is, leave it alone，Not suitable for handheld。Overall dimensions including microphone：27X10X6mm，working voltage 1.5-6V，Corresponding working current approx10-40 mA，OutdoorGPThe reference transmission distance of the antenna is about in an open environment10-500rice。The higher the voltage, the farther the emission distance, but the greater the power consumption，The optimum working voltage is3-5V，3VThe working current is only about15mA，Low power consumption。6VDo not use a single laminated battery or other similar low-power battery for power supply，Soon there will be no electricity。The circuit is amplified by a microphone+High frequency oscillation+RF amplification composition，Full chip separation element no integrated circuit，The working frequency is relatively stable，Slight frequency drift will occur due to voltage change or human induction，It is recommended to add voltage stabilizing circuit andASeries connection with antenna20PThe following small capacitors are conducive to stabilizing the frequency，The series capacitance will reduce the emission distance relatively。This module is small in size，Easy to load pen、Lighter, etc。The microphone is extremely sensitive，Can hear30Footsteps in the room。Power on to launch，The transmitting antenna can be soft wire or rod antenna，The length, height and efficiency of the antenna are directly related to the transmission distance，It can be determined according to the actual use needs。When the module is installed in the metal housing, the antenna shall be left outside the metal housing，Otherwise, the launch distance will be seriously shortened。The transmission frequency of this module is adjustable，The adjustable range is about98-115MHZ，Such as tune in98-108within，It can be received by ordinary FM radio；Such as tune in108-115MHZwithin，Ordinary FM radio cannot receive,It can effectively prevent leakage of secrets。The transmission frequency can be changed by adjusting the adjustable capacitance of the back patch。The module also has a micro patch potentiometer, which can be used to adjust the sensitivity of the microphone to sense sound。