Popular Electronics, Feb. 1969

[mikebg]

An ancient Induction Balanced Regenerator

In 1942 Americans have published this wrong circuit diagram of Russian mine detector. It operates as induction balanced regenerator. Does anyone have any more information about this kind Russian circuit diagrams?

[WM6]

In 1942 Americans have published this wrong circuit diagram of Russian mine detector. It operates as induction balanced regenerator. Does anyone have any more information about this kind Russian circuit diagrams?

Why do you mean it was wrong schematic?

Here is to read more:

http://www.lonesentry.com/articles/t...-detector.html

[mikebg]

Why do you mean it was wrong schematic?

Here is to read more:

http://www.lonesentry.com/articles/t...-detector.html

WM6, the block diagram is wrong, the circuit diagrams of both oscillators are composed incompetent, but more important is who has made the errors and how really the circuitry works. I nave the last version of correct block diagram and will publish it today.

[WM6]

WM6, the block diagram is wrong, the circuit diagrams of both oscillators are composed incompetent, but more important is who has made the errors and how really the circuitry works. I nave the last version of correct block diagram and will publish it today.

Small addition on this thema:

http://md4u.ru/forum/viewtopic.php?t=172


http://forum.blockhaus.ru/index.php?...18&#entry89518

http://www.trizna.ru/forum/viewtopic.php?f=13&t=37392

http://forum.blockhaus.ru/index.php?...18&#entry89518

http://forum.violity.kiev.ua/viewtop...d455d819def894

[Esteban]

WM6, nice links. I'm surprised how can be achieved some Russian MD schematics of IIWW, but German type can't be located, or am I wrong?

The pics of the links you posted show the importance of MD for the Red Army. Seems they was well equiped in this aspect. I remember that was posted by me a pic in Finland front (1939) during Soviet-Finland War. The pic is of a documental film, and show a team of detectorist in the snow.

[mikebg]

BLACK HOLE ANTENNA

Thanks WM6, you are not only a great searcher in WEB, and also a great finder. Despite today is April 1st - the international All 'Fools' Day, I hope you will find in WEB how can we make a small search coil to operate as a large conventional coil. Soon I will post the search phrases.

[technos]

"MMSI - selective portable induction metal detector. Control scheme allows to distinguish up to 16 classes of objects of the search, depending on the totality of the conducting properties of metals, sizes and shapes. Control scheme allows to distinguish up to 16 classes of objects of the search, depending on the totality of the conducting properties of metals, sizes and shapes.

Me thinks this was slightly "oversold."

[mikebg]

I hope you will find in WEB how can we make a small search coil to operate as a large conventional coil.

Metal detector with BLACK HOLE ANTENNA
The (R)EMI group forced me to start the thread "Popular Electronics, Feb. 1969" when the members reinvented the BFO (frequency shift) metal detector. The BFO MD is specific case of "Induction Balanced Regenerator" or IBR MD. At conventional BFO MD, the Barkhausen's criterium is satisfyed without target, thats why it allways oscillates in the absence of targets.
The normal IBR MD starts to oscillate only if there is a target, because the target closes the feedback path.
Experts of (R)EMI group say, the IBR MD has a lot of advantages:
Can operate in three modes. Can be designed as a narrow band metal detector with bandwidth maximum 12Hz (preferably 4Hz). Can be designed as broadband metal detector covering the whole audio frequency range (and even more when it should search for gold nuggets).
In narrow band mode, thermal noise is minimal, so there will be sensitivity superior to conventional metal detectors. It can be configured so that the Barkhausen's criteria can be fulfilled only for one species targets, thus discriminate against any other targets.
In a wide band mode, the IBR MD can be designed so that it starts to oscillate at frequency, which depends mainly on the target spectral characteristic. So you can use a frequency meter for visual (or spectrum shift with BFO for audio) TID (target identification). In continous oscillating BFO mode, it delivers more frequency shift than conventional BFO with monocoil.
The IBR MD is the most energy economical type detector because it not oscillates and no audio in the absence of targets. According Leslie Huggard, it operates with a 9V battery for almost one year. Due to negligible power consumption, it can be powered with photovoltaic battery.
Because of regeneration, the IBR MD operates as BLACK HOLE ANTENNA.
If you ask: "What means BLACK HOLE ANTENNA?", the answer is: "Search in WEB!"
You will find several documents written by John Sutton, Craig Spaniol and other NASA collaborants, which explain the term "Black hole antenna" or "Energy sucking antenna". Because of regeneration (positive feedback) the active antenna absorbs from environment more energy than expects from its dimension. That means when an IBR metal detector uses a small coil, it operates as if uses a large coil. This is illustrated with following drawing:

[mikebg]

From documents of NASA

Here's how looks the nearfield without regeneration (no BLACK HOLE EFFECT).

[mikebg]

And here is what happens with regeneration (there is BLACK HOLE EFFECT).

[mikebg]

Revised block diagram of regenerative metal detector

Revised block diagram of metal detectors in this thread. The previous name of block diagram INDUCTION
BALANCED REGENERATOR is changed in REGEN MD to satisfy 3 operational modes:
Mode A. The circuit allways oscillates. A specific case is the conventional BFO metal detector with monocoil. In this
case the mutual inductance between TX and RX coils is transformed in self-inductance of the monocoil. Because of
large AIR signal, the frequency shift at monocoil is minimal.
Mode B. The circuit operates as IB MD with "Black Hole Antenna". It starts to oscillate when there is target. If the loop
gain is wideband, oscillating frequency depends more of targets phase characteristic. A specific case is when the
loop gain is maintained to unity by slow acting AGC . Then the gain of amplifier should be so large, that TX coil
excitates target with rail-to-rail noise.
Mode C. The circuit oscillates without target. The target diminishes amplitude or stops oscillation. This is an absorbing
metal detector.

[WM6]

WM6, nice links. I'm surprised how can be achieved some Russian MD schematics of IIWW, but German type can't be located, or am I wrong?

The pics of the links you posted show the importance of MD for the Red Army. Seems they was well equiped in this aspect. I remember that was posted by me a pic in Finland front (1939) during Soviet-Finland War. The pic is of a documental film, and show a team of detectorist in the snow.

Bad luck, Esteban, no schematics of German WWII MD found to yet, only some descriptions, drawings and photos like this (but good for further search):

http://warandgame.wordpress.com/2008...detectors-wip/

http://www.militaar.net/phpBB2/viewt...7af0f0bd70a582

[Esteban]

Bad luck, Esteban, no schematics of German WWII MD found to yet, only some descriptions, drawings and photos like this (but good for further search):

http://warandgame.wordpress.com/2008...detectors-wip/

http://www.militaar.net/phpBB2/viewt...7af0f0bd70a582

The second link supossed that was found old German IIWW detector... with modern detector! What coincidence! Maybe Soviet and Allied has the schematic because they dismantle factories, labos... and take papers... and scientific at his service.

[mikebg]

Patents for ENERGY SUCKING ANTENNA

US patents of John F. Sutton
5,311,198 Active antenna
5,296,866 Active antenna
5,015,963 Synchronous demodulator

[WM6]

Maybe Soviet and Allied has the schematic because they dismantle factories, labos... and take papers... and scientific at his service.

Yes, very likely, there are some user manuals, but no schematic inside, only descriptions.