Resistor Chip Arrays
Product name: metal detector treasure detector DIY welding kit
Product model: TJ-56-520
Working voltage: DC5~12V
Measuring distance: 5cm (related to the size of the measured logistics)
Description:
Q1, L1, L2, C1, C2, R1 and RP form a high-frequency oscillation circuit. Adjust RP to make the oscillation circuit in a critical state, that is, make the oscillation circuit in a state of just starting vibration. Q2 and Q3 form a detection circuit. When the circuit oscillates normally, when the AC voltage generated by oscillation exceeds 0.6V, Q2 will conduct C4 discharge and short circuit in the negative half cycle, making Q3 cut off; When the detection coil is close to a metal object, eddy current will be generated in the metal conductor, which will increase the energy loss in the oscillation circuit and stop the vibration, so that Q2 will be cut off, C4 will be charged through R2, and Q3 will be connected to push the buzzer to make a sound. According to the sound, it can be determined whether there is a metal object under the detection coil.
Commissioning method:
The L1 and L2 of this machine are directly connected to the circuit board without self-made. The assembly is completed according to the component list. The power supply can be 5-12V DC. The positive pole of the power supply is connected to VCC and the negative pole is connected to GND. Slowly adjust the adjustable resistor RP until the buzzer sounds, and then adjust RP in the opposite direction until the sound just stops. Close the coil on the circuit board with iron objects, and the buzzer sounds, indicating success.
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Origin : Mainland China