LDC1000 CAN BE USED IN DOOR FRAME METAL DETECTOR OR NOT

What is the smallest size of a metal object to be detected?

As the door frame/walk through metal detector are meant for security purpose allowing the detection of any kind of metal ( from coin size to a big weapon size) when the person walk through it.

The door frame metal detector are of normally 7 feet high and 3 feet broad size allowing the easy passage of humans. And the coil (can be multi-turns) is distributed along the walls of metal detector. So virtually coil is of size of 7 ft x 3 ft distributed in rectangular shape. And the purpose of this type metal detector is to detect any kind of metal that comes inside the area of this coil in any position. So the least sensitive point for detection would be the centre of coil area.

      For above application, can the coils be directly connected to LDC1000 for tank circuit? or Is the signal conditioning required before feeding to LDC? 

Thanks

Jagpreet Singh

Hello,

No additional conditioning will be required.

As discussed earlier for door frame metal detector, our coil is of size 7ft x 2ft in rectangular shape (4 turns).

How to calculate Rp of LC circuit (using above coil specification) so that Rp_max and Rp_min can be calculated?

We don't have any impedance Analyzer with use. And how to handle this calculation if the no. of devices would be more as a production point of view? As each piece may vary with inductance of coil. Secondly, for this type of coil which type of capacitor you would prefer: SMD or Thru-hole?

Thanks in Advance.

Jagpreet Singh

Hello,

For this setup it's best to use the empiric method of Rp tuning, described in FAQ.

Hi, i'm new to this forum 

i'm interested in your response, please may you specify what do you mean with "additional conditioning "

required for metal detector application with huge coil .

Thanks

Hi, i'm new to this forum 

i'm interested in your response, please may you specify what do you mean with "additional conditioning "

required for metal detector application with huge coil .

Thanks

The signal conditioning means whether the output needs to be modified to handle this type of sensor, for example using a passive filter or even an active circuit. In general, the LDC1000 doesn't require signal conditioning.