LOOKING FOR GOLDSCAN 4 Schematic.

[Mehr076]

Both adjustments are very important. Potentiometer P2 (DELAY) is mounted on the front panel and is used to adjust the initial delay of the main sample, while VR3 is a trimmer located on the PCB used to adjust the remaining synchronization timings, in accordance with the diagram I published some time ago.

Thank you

[GeoMax]

Hi,

Like eduardo1979 already said... both are very important. To have the exact and correct timing is the important part in the detector.

[Mehr076]

Hi,

Like eduardo1979 already said... both are very important. To have the exact and correct timing is the important part in the detector.

Thank you

[Mehr076]

سلام،

همانطور که eduardo1979 قبلاً گفت... هر دو بسیار مهم هستند. داشتن زمانبندی دقیق و صحیح بخش مهمی در فلزیاب است.

I want to use a selector instead of a variable resistor.

[GeoMax]

Hello,

Then choose a selector switch instead of the potentiometer. What's the problem?

[Mehr076]

Hello,

Then choose a selector switch instead of the potentiometer. What's the problem?

I just want the adjustments to be more precise and easier to make, and I don't think a variable resistor would allow for greater precision.

[GeoMax]

Hello,

You can install a rotary switch instead of the potentiometer, as shown in this example. You can replace the potentiometers shown with a fixed resistor to simplify things, or you can use the potentiometers to adjust your resistance. For example, you could adjust the resistances on the potentiometers so that the delay is 10µs in switch position (1), 13µs in switch position (2), perhaps 20µs in switch position (3), and 30µs in switch position (4). There are actually many different adjustment possibilities.

[Mehr076]

Hello,

You can install a rotary switch instead of the potentiometer, as shown in this example. You can replace the potentiometers shown with a fixed resistor to simplify things, or you can use the potentiometers to adjust your resistance. For example, you could adjust the resistances on the potentiometers so that the delay is 10µs in switch position (1), 13µs in switch position (2), perhaps 20µs in switch position (3), and 30µs in switch position (4). There are actually many different adjustment possibilities.

Hello. Look, it needs to be connected to the selector exactly like this; the 10M resistor I’ve marked is placed in parallel with our selected resistor—the reason being that it prevents the IC's RC pin from floating. Since I didn't have the symbol for a selector switch for this schematic, I had to use a standard switch instead.

[GeoMax]

Hi Mehranfar,

I do not know your electronic skill level. But the example circuit I posted is the same of what you postet and of what you want. It only looks differently.

[GeoMax]

Hi Mehranfar,

If you look at the example diagrams below, you will see that it is the same circuit in both cases. The 10 MΩ resistor is unnecessary and can be omitted.

[Mehr076]

Hi Mehranfar,

If you look at the example diagrams below, you will see that it is the same circuit in both cases. The 10 MΩ resistor is unnecessary and can be omitted.

Hello. Yes, that is exactly it. Kudos to you for taking the trouble to send the full image.