Twin Loop Tr Seeker Highly modified

[Qiaozhi]

Unregistered , please send me your schematic ( 1 cent=55cm ) to [email protected]
I will make modification your sch to ClonePI-2.

Did you notice that the post you are replying to is nearly 3 years old!

[humhum]

schematic

TwinLoop detects coke can at 180cm in air, and a 1 cent at 55 cms, there are some modifications the opto will be 4N25 with a 270ohm(should be less than 400ohms at the transistor side to make the IC to be more than 50mA for fast turn on.), audio stage opto can be 4n35.

Modifications at preamp is Ne5534, and care has to be taken as both opamps are inverting along with TL081, and the next stage is an pnp transistor so re design has to be made to get a noninverting signal, if one of the opamp is configured as noninverting change the transistor to NPN as its base should be getting a positive voltage.

My Coil dia is 14inch and greater, Tx dia 0.5mm guage 30 turns, 0.1 to 0.2mm guage Rx 100 turns or greater, try different winding mechanisms for different results like spiral, buck coil etc etc....

Unregistered , please send me your schematic ( 1 cent=55cm ) to [email protected]
I will make modification your sch to ClonePI-2.

sharky please give more information about coils

please give more inf about circuit .and send some pic about coils

[12V]

Why use optocouplers, what this doing better?

[honesthunter]

please help

how can you detect a can at 180cm please give more information about schematics and loops

[Hush]

Hi Sharky!

Few years ago , I made twin loop treasure seeker and wasn't satisfy with it. Sensitivity in the air was very good, but at the field, it is very hard to work with TLTS. On flat ground it works good, but it start to beep on every
hole in the ground,in other words it suffer from ground effect.To works good
ground must be almost perfect flat.I beleve you that TLTS is so sensitive with that FET, but did you try it in real conditions?
Merry Christmas, and happy new year!

Wish you all the best!

hey SHARKY please help

please give more information about the coils

please help about twin loop

how can you detect a can at 180cm please give more information

[erolunall]

really
if it is real most powerfull dedector

TwinLoop detects can 180cm

TwinLoop detects coke can at 180cm in air, and a 1 cent at 55 cms, there are some modifications the opto will be 4N25 with a 270ohm(should be less than 400ohms at the transistor side to make the IC to be more than 50mA for fast turn on.), audio stage opto can be 4n35.

Modifications at preamp is Ne5534, and care has to be taken as both opamps are inverting along with TL081, and the next stage is an pnp transistor so re design has to be made to get a noninverting signal, if one of the opamp is configured as noninverting change the transistor to NPN as its base should be getting a positive voltage.

My Coil dia is 14inch and greater, Tx dia 0.5mm guage 30 turns, 0.1 to 0.2mm guage Rx 100 turns or greater, try different winding mechanisms for different results like spiral, buck coil etc etc....

[sharky]

Twin Loop Tr.Seeker Layout

Use Ne5534A or Lm66xx series of Opamps for good noise figure, and see that the opamp is working in diff. mode remove, omit R14 in the original schematic, omit Q1 in Original. Layout of new components attachment is below..

[sharky]

Highly Modified Twin loop Circuits

Due to lack of time the design was done in MicroShift paint

Important use Ne5534A in place of 709 and use appropriate balance circuitry

The sampling delay can be 5 usec , variable Tx Twidth, Sampling time variable.

use separate 9v Radio batt for opto2

use 2 9volt batt for front end recieve ckt's for driving 78L05 and 79L05

use a Lead Acid batt for Mosfet Driving Circuitry.

[sharky]

Here is the Twin Loop treasure Seeker modified with optocouplers to separate the power supplies and a second opto to separate the speaker circuitry, and one Bipolar transistor which drives the coil is removed, and other transistor is replaced by FET IRF840...

Original pcb tracks are intact for adding the dual coils both in recieving mode, a third Tx coil is large (1.5 foot dia) which contains these 2 Rx coils (7inch in dia) dia, turns etc depends on the damping resistors used and experimentation.