As shown in the figure, the car search device includes a transmitter and a receiver. The transmitter uses 555 as the core to form a medium-wave frequency oscillator. The oscillator frequency should be chosen to be slightly lower than the carrier frequency of the broadcast amplitude modulation 535KH Z. The frequency value is determined by R 1 , RP 1 and C 1 , that is, f=1.44/( RP 1 +2R 1 )C 1 , L 1 , C 2 form an output resonant tank, which is selected and then transmitted through the antenna through C3. The receiving circuit consists of an input frequency selective network and a 741 operational amplifier. The amplification factor of the amplifier depends on the ratio of RP 2 /R 2 . LED 1 ~ LED 5 is used to indicate the strength of the received signal, as the signal is strengthened, the LED will be illuminated sequentially! ! Fiber Optic Splice Closure,Fiber Optic Splice Case,Fiber Splice Closures,Outdoor Fiber Optic Splice Closure Cixi Dani Plastic Products Co.,Ltd , https://www.cxdnplastic.com
November 30, 2024