Pulse Star II (first analog version)

[Jose]

I've been running some tests. The 200k and 82k resistors and the 1.2nF capacitor near the 4022 IC set the initial and final sampling times, as well as the transmission pulse width. They also influence the delay.
I replaced the 82k resistor with a 130k resistor, and the transmission pulse width was adjusted to 200us without affecting the other parameters.
Current consumption increased from 105mA to 185mA.
Air tests show an improvement in detection distance; this remains to be tested in the field.

[Orbit]

Thanks, Orbita. The module I purchased is working fine with the LF444 instead of the TL064CN. I can't get the reset to retain the audio threshold when approaching bricks or iron pliers. Various TL064Ns and other CA3130s have been tested; I don't know if these last ones are counterfeit.
The detector is sensitive and stable; the power consumption without the discrimination module is low, around 105 mA.
I would like to modify the TX pulse width to obtain greater depth. Perhaps the 4022 can be reconfigured.

Pay attention to the components marked in red, the pulse width can be increased by replacing 1nf with 1.4nf from 100us to 150us.

[Jose]

Thanks, Orbita. The module I purchased is working fine with the LF444 instead of the TL064CN. I can't get the reset to retain the audio threshold when approaching bricks or iron pliers. Various TL064Ns and other CA3130s have been tested; I don't know if these last ones are counterfeit.
The detector is sensitive and stable; the power consumption without the discrimination module is low, around 105 mA.
I would like to modify the TX pulse width to obtain greater depth. Perhaps the 4022 can be reconfigured.

[Orbit]

Here is a photo of the original pcb motherboard where most of the ic components can be clearly identified..

[kt315]

Oh... the Pulse Star II detects a Coca-Cola can at 1,3m only? I expected much more.

cola can is small target for 1x1 frame coil so do not wait good depth. normal-standart one is steel Wehrmacht helmet. it's good for the test on depth.

[GeoMax]

Oh... the Pulse Star II detects a Coca-Cola can at 1,3m only? I expected much more.

[algan]

Today I asked a colleague who had the original Pulse Star 2 and tested it with a 330 ml Coca-Cola can with air and a 1x1 meter frame. detected 1.30 meters. This is so that colleagues who make the board know what the capabilities of the original are.

[Orbit]

And in the third case, the lf357 preamplified

[Jose]

Thanks, Orbita. I ordered the CA3130 and it should arrive this week. I hope it's not a fake. The 150V zener came with the module I purchased. The module doesn't include a damping resistor. I installed the resistor I was referring to in the coil and housing myself.
I'm researching the LM358...

[Orbit]

If I understand correctly a damping resistor is put on the pcb? I also did not find a resistor inside, the original ones are only in the coil. It occurred to me that this is where the problem lies, because every time I remove the resin from the PCB, I always have a problem with the detector( The threshold) is not controlled.without the coil with the original parts. However, if someone has access to the original device, you can test your pcb on the original, you will see that the meter does not go all the way where it says the battery is full, but only in the first third of the meter, which indicates something that exists on the lm358, a missing component!?

[Orbit]

If it should behave like that, for example, you can test iron pliers to see if it memorizes approximately 10 cm from the coil, if it memorizes them, then the Ca3130 is fine, if it doesn't memorize or memorizes them further and you can't set the threshold, the problem is in the Ca 3130, which means it's fake! 033ml box that cola or other pizza should detect at about 110 to 120cm with Lf 444 with Tl 064 is less sensitive clock one click per second should be stable until the next reset.I did not find a 150v zener diode in any module, they were all 51v.

[Jose]

I bought a PS2 module from AliExpress and am testing it.
The 150-volt zener installed next to the IRF630 isn't working. The MOSFET goes into avalanche mode at 200V, as can be seen with the oscilloscope, and it heats up slightly.
However, the zener works fine. I removed it and tested it with a variable power supply. Since I don't have a 51V zener on hand to test, I installed a 130V P6KE130A overvoltage protection diode in series with a 15-ohm resistor. The flyback is now limited to 190V.
Afterwards, I tested several coils I had available. The best one was a 45 cm diameter coil made with 660 uH UTP cable. The damping resistor installed in the detector box was 620 ohms. The coil also has a 2.2K resistor inside.
I installed a socket in the TL064's location, which is erased, to test other ICs. The LF444 works better than the TL064, as Orbita claims.
However, with the original IC erased, pressing the reset button with the coil near a brick adjusts the threshold and remains memorized. This doesn't happen with the LF444 and TL064 I tested.
Finally, the PS2 is working with good sensitivity and stability. I don't have an original detector to compare, but it is similar to the Orbita video.

[Orbit]

https://youtube.com/shorts/m2DYWhcvv...qzSmgHKlz70IT8

[Orbit]

With LF411, the device always has a smaller depth. The preamplifier needs LF357, but you may face the problem described. The cable is important, as is the inductance of the coil and the value of the damping resistor.

[ivconic]

The PS2 Pro I've mentioned a couple of times before, originally mine and later sold to a friend locally, is almost always at my disposal.
When I built the first few PS2s, I picked up a PS2 Pro from a friend to compare.
It's true, I didn't reach the same "depths" in the air either. I got about 85-90% performance.
I can interpret it in various ways. Different quality of components, this, that... but first of all I think it's the coil.