METAL DETECTOR TESORO TSGL
METAL DETECTOR TESORO TSGL SCHEME
We present another rather successful scheme of the Tesoro Golden Sabre Light metal detector . In the lightweight version there is a discrimination mode and an all-metal mode, switched by a toggle switch. When installing parts according to the scheme, everything is balanced, when switching, there is no need to change the sensitivity. Ground balance is a trimmer resistor, you can adjust it by ferrite during setup and also check the range with a copper coin, so that the range is maximum and the ferrite is not visible, and do not touch it anymore – but this is already with a ready-made coil.
Schematic diagram of a metal detector
Drawing of the printed circuit board and the parts on it
In the process of making Golden Sabr, I found an extra function that Ivkonik cut off on Geotekh. When setting up the BG (adjuster), take a piece of ferrite, wave the ferrite, and twist the BG. The moment comes – the ferrite is not visible. If the BG is left in this position, then the copper is not visible either. And it turns out very convenient: we can clearly see all the gold and silver rings – and nothing else. No foil, no plugs, no walking. If you then twist the BG a little further, then the copper appears.
Schematic diagram of the metal detector – modification
The first time I did it, I tuned it off the ferrite, and then adjusted the BG to the maximum on copper (as I do on the Eldorado). That’s why I skipped this extra function. And now it makes sense to bring the BG to the panel and use it when you don’t want to assemble a walkie-talkie. And if it beeped, then it’s definitely some kind of ring. And if you want to find a cross, turn off the discrimination mode.
I would like to remind you that if you make a sensor for TSGL, the frequency difference is around 1500 Hz.
During the setup I found a problem, maybe it will be useful to someone, the matter is in the minus converter, transistors 2222 and 3907 cannot work normally, I recommend pairs 2N3906 – 2N3904 or BC327\328 – BC 337\338, as well as from the BC547\548 – BC 557\558 series. As a result, the parameters were obtained: current consumption 25 mA at Usup. – 12 volts, a patch on the coil 175 mm – 22 cm, it is adjusted from the ferrite without problems, I also tried iron scissors, nippers – the metal detector does not see them.
The GSL board has a power stabilizer deployed. I didn’t see it right away and spent two days fiddling around. It turns out that it doesn’t stabilize anything, but works like a regular resistor. That’s why the device works differently each time.
The 100 pF capacitor is installed only for LM308 (to eliminate the excitation of the microcircuit). If a replacement is installed (TL081, i.p.), then these capacitors do not need to be installed! This was written about both here and on Geotech.
Replacement of CD4024 – K176IE1, LM308 – NE5534 microcircuits. Our UD1408 work well instead of LM308. For Tesoro
TSGL, the frequency of the receiver together with its 15nF capacitor should be 1400-1500 higher than the detector frequency. For Eldorado – 500-600 Hz (with 33nF). It is adjusted using a generator for coils.
How to make a sensor on Eldorado – exactly the same on TSGL, only the frequency is 15 kHz and the receiver is set to 16.5 kHz. I got Tx – 102 turns, Rx – 85+85 turns Cx – 25 turns. But until you do all this exactly according to the frequencies, it is difficult to set up the detector. I advise you to download the calculation calculator – very useful.
The DD sensor is manufactured according to the same principle as for all balancers, so I will only dwell on the required parameters.
– TX – transmitting coil 98 turns 0.27
– RX – receiving coil 107 turns 0.27 enameled winding wire.
Next, we shield the receiving coil with foil. We set up the coils, connect the generator for the coils directly to the contacts on the board in TX, capacitors C1 and C2 should be soldered to the board, measure the frequency and connect the generator in place of RX to achieve a frequency 1500 Hz higher than TX.
Attention, a small addition. There have been some changes in the Tesoro Golden Sabre Light metal detector circuit. The resistors R29 and R31 have a value of 1M. Capacitors C14 – C14b and C17 – C17b are 10mF each. R36 and R37 have been removed, and R39 with a value of 100k (although 10k also works) is connected to R43, which is now 100k. Be careful when installing. Unfortunately, it is not possible to make these changes to the pdf document – use the pictures as a guide.
Instead of transistors 2n2907 and 2n2222 in the -5v voltage source, put BC547 and BC557 – they work 100%. Only the pinout is different, be careful not to mix them up. Field-effect transistors – bf245. Transistor bd140 will be replaced with kt814. There is also a version of the circuit and board from Eduardo from the Geotech forum , but I have not personally assembled it, so I can’t say anything.
Schematic and board version of the TSGL metal detector by Eduardo
In the course of upgrading the metal detector, I tried to assemble and connect the VDI module to the TGSL , but I didn’t really like something – there was a bad reaction to non-ferrous metal, I put this issue off until better times…
VDI module diagram
Video of the operation and capabilities of the metal detector:
Winding data of coils
– TX diameter 200 mm, wire 0.25 mm 102 turns, inductance 6.056 mH.
– RX-diameter 100 mm, wire 0.25 mm, 166 turns, inductance 6.537 mH. – CX-on top of RX, wire 0.25 mm, 28 turns (then unwound during setup). Here everyone will have their own number of +\-.
The TX and RX coils are wound in the SAME direction! CX towards TX. The end of TX is connected to the beginning of CX. I am making a separate manual for more details on the manufacture and adjustment of the ring. The material was prepared and provided for publication by: DEXXTER933659 , Eduardo 1979 , Elektrodych .