Post by Deleted on Apr 5, 2011 17:09:08 GMT -8
Use of digital processing allows considerably to simplify an electronic part of the detector. But to keep thus main units. It is a power unit, generator of pulses, preliminary amplifier and two (one) coils.
For example for the project hammer head it is possible to remove microcircuits IC7, IC8, IC9, I1C1, IC12 and components for them.
The presence of metal is defined(determined) on change of the integrated sum for the chosen period of time . There is no necessity to move by the search coil to the left to the right. At a finding of the coil above metal object the sum of integration at once is increased.
At 16 bit of sound card it is possible to catch even insignificant changes of this sum, that considerably increases sensitivity of the detector. The sensitivity theoretically will be equal 1/16384. Actually it it is a little less, but substantial growth of sensitivity in comparison with existing types of detectors. (Pulse induction MD). Using regression analyse for digital processing of a signal allows to discrimination of the metals.
But it is necessary to know that resolution of the digital detector much more depends on a used sound card (if at processing a signal the sound card is used). The resolution on time depends on sample rates. And on amplitude from number bits (8, 16, 24 bits).
The program made mine, is oriented on a card with 8/16 bits and sample rates (11025 to 48000 sps). It is possible to be switched to 8 bits at frequency 96000. But then the resolution on amplitude (1/256) decreases.. Time resolution is 10 micro seconds (it is considerably increased)
The variant of my program of the pulse analyzer is placed below. And you can free download . But it is necessary to remember that the level of input signal (after the preliminary amplifier of the detector) must be less 0,5 volts. In mentioned variant of program is adjusted on a sound card Realtek AC97. If You to use other card that it is necessary to make changes to the program (tell me at wl19141918@gmail.com).
Uploaded version of program is freeware
For example for the project hammer head it is possible to remove microcircuits IC7, IC8, IC9, I1C1, IC12 and components for them.
The presence of metal is defined(determined) on change of the integrated sum for the chosen period of time . There is no necessity to move by the search coil to the left to the right. At a finding of the coil above metal object the sum of integration at once is increased.
At 16 bit of sound card it is possible to catch even insignificant changes of this sum, that considerably increases sensitivity of the detector. The sensitivity theoretically will be equal 1/16384. Actually it it is a little less, but substantial growth of sensitivity in comparison with existing types of detectors. (Pulse induction MD). Using regression analyse for digital processing of a signal allows to discrimination of the metals.
But it is necessary to know that resolution of the digital detector much more depends on a used sound card (if at processing a signal the sound card is used). The resolution on time depends on sample rates. And on amplitude from number bits (8, 16, 24 bits).
The program made mine, is oriented on a card with 8/16 bits and sample rates (11025 to 48000 sps). It is possible to be switched to 8 bits at frequency 96000. But then the resolution on amplitude (1/256) decreases.. Time resolution is 10 micro seconds (it is considerably increased)
The variant of my program of the pulse analyzer is placed below. And you can free download . But it is necessary to remember that the level of input signal (after the preliminary amplifier of the detector) must be less 0,5 volts. In mentioned variant of program is adjusted on a sound card Realtek AC97. If You to use other card that it is necessary to make changes to the program (tell me at wl19141918@gmail.com).
Uploaded version of program is freeware
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