Papan penyebaran detektor logam elektronik, Sederhana DIY

Papan Spreading Detektor Metal Elektronik Simple DIY Pre-Order. Perkiraan Sampai 10-15 Hari Beli DISINI, dari China GRATIS PAJAK Garansi Uang kembali apabila barang Rusak, Beda Ukuran/Produk New board simple metal detector kit Kit parameters: Power supply voltage: 3-5V; Size: 66x61mm; Detection distance: 5CM; Special caution: this kit is located as an electronic teaching kit, mainly for welding and learning working principles, can not really explore treasure, induction distance within 5 centimeters. This product is welding loose parts, need to have a little electronic knowledge and welding skills, do not shoot, no technology know, after welding can not be replaced!!! Q1, L1, L2, C2, C3, R1 and W make up high frequency oscillator circuit, regulating potentiometer W, which can change the oscillator-level gain and put the oscillator in a critical state of oscillation, that is to say, just make the oscillator vibrate.Q2, Q3 consists of a test circuit, and when the oscillator voltage ac voltage exceeds 0.6 v, Q2 short circuites C4 diskharge in negative semi-weekly conduction, resulting in Q3 cut-off; when the probe coil L1 is near a metal object, vortex currents are generated in the metal conductor, increasing energy loss in the oscillator circuit, reducing positive feedback, and even weakening the oscillator in critical stateThe minimum energy required to stop vibration, make Q2 stop, R2 charge C4, Q3 guide, promote buzzer sound.Depending on the sound, it is possible to determine whether there are metal objects under the probe coil. According to this principle, the circuit can be effectively modified into a close switch for elevator floor 750