Showing posts with label metal. Show all posts
Showing posts with label metal. Show all posts
Tuesday, October 1, 2013
Metal Detector Based on the TDA0161
These metal detector circuit diagram is based on the TDA0161 monolithic integrated circuit , designed for metallic body detection by detecting the variations in high frequency Eddy current losses. For detecting metals , TDA0161 require an external LC tuned circuit .
Metal Detector Circuit diagram
Output signal is determined by supply current changes. Independent of supply voltage, this current is high or low according to the presence or the absence of a close metallic object. This metal detector circuit use two LEDs , which offer an visual indication of presence or absence at a metals ,around the coil . To adjust the circuit you need to make sure there is no metal near the coil and then set the fine adjustment to a "Mid position". After that you need to adjust the course adjustment to turn on the LED and , adjust the fine adjustment to turn off the LED.
This detector electronic circuit operates over a wide range input voltage of 4 -35 volts . If you want you can use other values for the Cx capacitor and for L1 inductor ( changing this value will affect the frequency oscillation and the detection range ) .
Metal Detector Circuit diagram
This detector electronic circuit operates over a wide range input voltage of 4 -35 volts . If you want you can use other values for the Cx capacitor and for L1 inductor ( changing this value will affect the frequency oscillation and the detection range ) .
Sunday, September 22, 2013
Metal Detector Schematic Circuit Diagram
Metal Detector Schematic Circuit DiagramThe ambit declared actuality is that of a metal detector. The opera- tion of the ambit is based on superheterodyning assumption which is frequently acclimated in superhet receivers. The ambit utilises two RF oscillators. The frequencies of both oscillators are anchored at 5.5 MHz. The aboriginal RF oscillator comprises transistor T1 (BF 494) and a 5.5MHz bowl clarify frequently acclimated in TV sound-IF section. The additional oscillator is a Colpitt�s oscillator realised with the advice of transistor T3 (BF494) and inductor L1 (whose architecture capacity follow) shunted by trimmer capacitor VC1. These two oscillators� frequencies (say Fx and Fy) are alloyed in the mixer transistor T2 (another BF 494) and the aberration or the exhausted abundance (Fx-Fy) achievement from beneficiary of transistor T2 is affiliated to detector date absolute diodes D1 and D2 (both OA 79).
The achievement is a pulsating DC which is anesthetized through a low-pass clarify realised with the advice of a 10k resistor R12 and two 15nF capacitors C6 and C10. It is again anesthetized to AF amplifier IC1 (2822M) via aggregate ascendancy VR1 and the achievement is fed to an 8-ohm/1W speaker. The inductor L1 can be complete application 15 turns of 25SWG wire on a 10cm (4-inch) bore air-core above and again cementing it with careful varnish. For able operation of the ambit it is analytical that frequencies of both the oscillators are the aforementioned so as to access aught exhausted in the absence of any metal in the abreast around of the circuit.
The alignment of oscillator 2 (to bout oscillator 1 frequency) can be done with the advice of trimmer capacitor VC1. When the two frequencies are equal, the exhausted abundance is zero, i.e. exhausted frquency=Fx-Fy=0, and appropriately there is no complete from the loudspeaker. When chase braid L1 passes over metal, the metal changes its inductance, thereby alteration the additional oscillator�s frequency. So now Fx-Fy is not aught and the loudspeaker sounds. Appropriately one is able to ascertain attendance of metal
The achievement is a pulsating DC which is anesthetized through a low-pass clarify realised with the advice of a 10k resistor R12 and two 15nF capacitors C6 and C10. It is again anesthetized to AF amplifier IC1 (2822M) via aggregate ascendancy VR1 and the achievement is fed to an 8-ohm/1W speaker. The inductor L1 can be complete application 15 turns of 25SWG wire on a 10cm (4-inch) bore air-core above and again cementing it with careful varnish. For able operation of the ambit it is analytical that frequencies of both the oscillators are the aforementioned so as to access aught exhausted in the absence of any metal in the abreast around of the circuit.
The alignment of oscillator 2 (to bout oscillator 1 frequency) can be done with the advice of trimmer capacitor VC1. When the two frequencies are equal, the exhausted abundance is zero, i.e. exhausted frquency=Fx-Fy=0, and appropriately there is no complete from the loudspeaker. When chase braid L1 passes over metal, the metal changes its inductance, thereby alteration the additional oscillator�s frequency. So now Fx-Fy is not aught and the loudspeaker sounds. Appropriately one is able to ascertain attendance of metal
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