Stone Crushing Metal Detector

Other details:

• Target Micro Scan metal detectors use a balanced, three-coil, system to detect small particles of non-ferrous and stainless steel
• The coils are wound on a non-metallic frame, each parallel with the other
• The centre coil is connected to a high-frequency radio transmit­ter
• Coils on either side of the transmitter coil are receivers
• As these two coils are identical and placed the same distance from the transmitter, they receive the same signal and produce an identical output voltage
• When the coils are connected in opposition, the output is cancelled, resulting in a zero value
• A schematic of the coil configuration is shown in figure 1
• When a particle of metal passes through the coils of a metal detector, the high-frequency field is disturbed under one coil, chang­ing the voltage by a few micro volts
• The state of balance is lost and the output from the coils is no longer zero
• It is this phenomenon that is used to detect metal.