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Originally posted by Jose
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Jose, the high voltage across the mosfet ? Can you describe this more ? -
Hi Greylourie
The use of a series diode between the MOSFET and the coil continues to exist high voltages in the MOSFET, as can observed in "IMG 1" picture.
In "IMG 1" the limiter is disconnected. Each box represents 50V, the peak voltage, out of scale in ociloscopio.
In "IMG 2" with the limiter enabled, observed the peak voltage, is cut before reaching 400 volts.
In the "voltage limiter 2" scheme, is observed the point where the ociloscopio was connected, for measurements.
Jose
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Originally posted by Jose View Post
Correct me if I'm wrong, in Limitador de Tension 2.JPG
R8 - 10K
R16 - 1R / 2watt
C3 - 4700uF/2x4700uF/10000uF 16V
The diode connected with the drain of the Mosfet can be 200V (example: BYV28-200- this is seen on PIM-2 schematic, also in SD2000),
though this is opposing of the suggested high voltage STTH1210 (1000V), perhaps this diode is not meant to limit voltage of the mosfet in the delta pulse unified.Comment
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The component values are correct.Originally posted by eclipse View Post
As for diodes, the truth is that I'm using components recovered from old monitors.
When I see the values, I consult online, and you chose the highest tensions, and 3 ampere current .
I think it's wise to choose values greater than 500 volts, for DP.
JoseComment
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Cheers, Jose.
For the images you posted, and commentary describing them.
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Originally posted by kt315 View Postthis is last test I do before it will be shipping to mege. you are witnesses.
hey! LOOK YET THE VIDEO AGAIN - ALL WORK! no claims to me nowhi,I receive my package today,thanks
I can not run the circuit,
You can not isolate the coil cable as well
coil cord tightly with tape not well
(
later realized as long as the coil cable short circuit
crystal tape stopped burned smoke output circuit...No audio circuit?
Do you think electronic circuit was damaged? or Where it is damaged?
.....
How do I attach the coil circuit
should be few ohms? Please write to me necessary measure coil
30cm, 60cm1x1 and 2x2 dimensions and coil resistance value should be what?
Please help me, I feel so bored I'm so sorry
you are unserious man.
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Write a private message!!Originally posted by kt315 View Posthey! LOOK YET THE VIDEO AGAIN - ALL WORK! no claims to me now you are unserious man.
I ask you questions,, I want to help..
what did you do?..
I sent you private messages you showed everyone!
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Hi all
Delta pulse is not sensitive for gold.what?
Thank youComment
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hi
no answer
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.... Delta Pulse was not designed to be sensitive to gold, but for medium and large objects. You can reduce the delay a bit, as discussed before, but has a slightly slow response.Originally posted by pigeon View Posthi
no answer
Delta Pulse is excellent for large coils.
For gold is better Minipulse, Surf Pi, Goldscan 4, etc. etc..
JoseComment
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many times was written in this thread. you may decrease MAIN SAMPLE DELAY by decreasing R7 and C4=1nF to 10-12usec, at min pot position meant. also you
may decrease SAMPLE WIDTH by decreasing C5=1nF. PLEASE MORE NOT ASK HOW TO RETUNE DP ON GOLD. this matter IS CLOSED
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I would like to clarify a few points for those trying to adjust the DP to make it more sensitive to gold.
It is true that changes may be made to take the first sample to 10 microseconds.
However, pimera preamplifier stage, must also be fast enough, and in practice, I have found that in the DP, the front stage as it is called, has a minimum of about 17 or 18 microseconds.
So there is a limit imposed by the response of the front stage, which I understand is for the design of the DP.
For this reason the PI detectors designed to have a quick response, are usually designed with two stages front, just to decrease the response time.
It is true that these issues were discussed many times, but we fans always have doubts and appreciate those who are willing to clarify.
JoseComment
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I still offer to SAY WHAT gold you mean. if you mean 500 gramm gold mask then DP is sensitive to it. if you mean gold NUGGET so write WHAT SIZE of the nugget you mean.Comment
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Hello KT315
What I'm trying to say is that the Delta Pulse, hardly can have performance with detectors specially designed for detecting small nuggets of gold, these detectors respond well to about 10 microseconds, where the delay control is set and the front preamplifier is designed to respond to these values.
Logically I am referring to small nuggets of a few grams.
I have no gold nuggets for the tests, but I can mention one example.
Com my GS4, working the delay in about 12 or 13 microsecond, can be detected in the air for a gold engagement ring, about 38 cm.
My DP adjusted with the delay, about 18 microseconds, the same ring, we can detect some 30 cm or more in the air.
Could adjust the DP about 15 microseconds or less, but improvement is not obtained and becomes noisy, for the reasons mentioned in the previous post.
It is hoped that these differences are accentuated, with decreasing size of the object.
But if I make the measurements with a bronze coin, the two detectors has almost the same performance, with the settings above.
These distances above depend on many factors and may vary, but serves as example.
Regards
JoseComment
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