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write measured values of
r4 c3 and pot DEPTH.
r4 c3 and pot DEPTH.
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Considering last images (Tr3min280uHcoil.png and Tr3max280uHcoil.png), and given ranges 100-700us, values are:
R4 3.91k (measured)
C3 22n (I can't measure capacitors, so I give printed value)
DEPTH 25k
Previous measures (range 60-350us):
R4 5.59k (measured)
C3 10n
DEPTH 25kComment
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Also, I see on your schematic STTH1210D diode, can I use MBR1035 instead?Comment
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Images Tr3min.png and Tr3max.png are made with 830mH coil. Is it too much inductance? Another coil I have is 280mH.Comment
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Schottky is not able work in circuits where more than 50V. guys, learn the blsht electronics, more books around you are able get in global net.Originally posted by rankx0 View Post
do not ask me primitive questions. here is forum for metal detectors, not for absolute beginners.
you need be looking for more than 1000-1200v diode.
SCHOTTKY IS LOW VOLTAGE DIODE. its the rule!Comment
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OK, I had no idea that there would be more than 50V in this circuit! Thanks!
Also, I have bought another oscilloscope probe, so there are measurements for Tr3 and Tr4. When I compare signals on those points, I have 30us minimal and 130us maximal delay between imuplses, depending on Delay (or Sensitivity) potentiometer position. Are those values OK, or I need to adjust something?
Delay between Tr4 and Tr5 is 115-930ms:
I suppose that is correct?Comment
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OK, I had no idea that there would be more than 50V in this circuit! Thanks!
DELTA PULSE is "delta" pulse! P-P amlitude of delta pulse is getting 1000-1200 Volts on maximum PULSE WIDTH 500us!
why do you not want to grasp what is the delta pulse???Comment
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I have some knowledge on electronics, I have built lot's of audio stuff, but this is my first detector. Excuse my ignorance, I am still learning and want to learn a lot
I am trying to figure out which components I can change, since it is not possible to buy some "exotic" stuff like that diode here where I live. According to what you say, I believe that DSEI12-12A could be the replacement, since that is the most similar diode I can find here (1200V / 11A / 50ms). And if switching speed and power are not critical, I could use RGP30M (1000V / 3A / 500ms).
However, thank you very much on your help, your knowledge is great and everyone can lear a lot from you! I'll be very grateful if you can comment my oscilloscope measurements.
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This might be of interest -> Inside the METAL DETECTOR - Second Edition - Published 2015Originally posted by rankx0 View PostI have some knowledge on electronics, I have built lot's of audio stuff, but this is my first detector. Excuse my ignorance, I am still learning and want to learn a lot
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"exotic" stuff like that diode here where I live.
what is your country???? exotic for United Kingdom too rich state in the world?
https://www.lemona.lt/?sn.q=STTH1210
even for u-state like Lietuva the cost of the diode is 1.5-3 euro!Comment
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Dear KT351, I live in Serbia, not UK. The price is not the problem, it simply can not be found here, and I am searching for alternative. Thanks for understanding.
Qiaozhi, thank you for this link!Comment
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ok! i have Maxymus in skype. if you want something from your place ask him, i will give you his account.
also you may rely on ivconic - Ivitsa as he is a super-active geo techers. overload his message box by requests,
he will be happy!Comment
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OK, I've messaged ivconic. Thanks! But you could also answer about maximum current through diode? Is 11A enough?
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Here's where you can see the catalog features everything you want. http://www.alldatasheet.com/Originally posted by rankx0 View PostOK, I've messaged ivconic. Thanks! But you could also answer about maximum current through diode? Is 11A enough?
I tried STTH1210 but honestly coil 20cm decreased sensitivity to small objects, so try with or without diode and see the difference.
Read this :
http://www.geotech1.com/forums/showt...704#post225704Comment
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Look here: http://store.comet.rs/rs/Search/?key...IxMEQifQ%3D%3DOriginally posted by rankx0 View PostOK, I've messaged ivconic. Thanks! But you could also answer about maximum current through diode? Is 11A enough?Comment
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