Simple Russian PI detector Pirat

[Funfinder]

This is super but the question now is what can we add (between rx and tx or after rx)
to get some simple discrimination.
And of course the depth together with voltage should be improved.

[BKY1337]

My NE555 was damaged, i replaced it with a new NE555P and now i have a sound output at pin 3 with Speaker/Resistor,
but the detector doesnt work. I dont want to order a new K157ud2 , i have a TL082 , i think its possible to connect the 8 pins from it to the 14 pin socket.

[BKY1337]

I have measured my Pins from the K157ud2 while connected to a battery.

Pin 10 and 12 begins with 0 mV and it grows until 300mV and then the multimeter displays 0L and then it begins again from 0 mV

Thanks in advance.

[BKY1337]

The NE555 Tool says that the Output frequency should be about 140Hz . But it's 0,2 kHz --> 200kHz. Maybe its because of my multimeter or because of different sized resistors.
I think the Coil should be under voltage , even when the k157ud2 is damaged, or not? How much voltage is normal for the coil?

[homefire]

Petty much your Battery Voltage.

[BKY1337]

I cant get the battery voltage at the coil connectors, because its + at the one side and + at the other.
When i connect the multimeter to ground and to the middle bar , where the mosfet drains into and also the damping resistor is then i have about the battery voltage
maybe a little less , 7,6 V or something like that. I have also a positive voltage when i connect ground and the other coil connector to the multimeter, because its the upper and the lower rail, + and -.

I dont really know how it works, do i need to have a + and a - at the coil wires?

The NE555 is the oscillator,which brings the irf740 to drain the battery voltage into the coil. I still need to learn how the right part of the circuit works.
I think its just for the audio and for the processing.

But i have only about 150mV at the coil , and between the positive rail and where the mosfet drains into.

When i connect my conductivity meter , which has a speaker in it between the positive rail and the base of the transistor at the right side , then the speaker makes a loud sound , louder than the speaker in my conductivity meter, so i think something got amplified.

[homefire]

I cant get the battery voltage at the coil connectors, because its + at the one side and + at the other. No ! Coil out is connected to Pos. Coil in is sourced by Neg from Fet.
When i connect the multimeter to ground and to the middle bar , where the mosfet drains into and also the damping resistor is then i have about the battery voltage
maybe a little less , 7,6 V or something like that. I have also a positive voltage when i connect ground and the other coil connector to the multimeter, because its the upper and the lower rail, + and -.

I dont really know how it works, do i need to have a + and a - at the coil wires?

Yes, Coil in is Neg and Coil Out Pos.

The NE555 is the oscillator,which brings the irf740 to drain the battery voltage into the coil. I still need to learn how the right part of the circuit works.
I think its just for the audio and for the processing. Yes Audio is produced by the coil switching.

But i have only about 150mV at the coil , and between the positive rail and where the mosfet drains into. That is the Voltage Drop caused by the coil.

When i connect my conductivity meter , which has a speaker in it between the positive rail and the base of the transistor at the right side , then the speaker makes a loud sound , louder than the speaker in my conductivity meter, so i think something got amplified. Yes, BC547B is the Audio Out Put. You injected signal on input.

See within the Quote.

[BKY1337]

I get positive between the coil in and coil out (yellow connections) 150mV, that means i have two positive coil connections. Maybe a damaged damping resistor? Or maybe everything here is ok?
And its the right section of the circuit. I think the coil was not connected.

But this doesnt matter, i had a sound signal before without coil.

I have battery voltage between the red ones , because this is nothing else than the battery.
I think my mosfet works , because i have tested it on function with a multimeter and i have a oscillating signal at coil in/ground.

I made all measurements without coil.

Why is there an arrow at the polyester capacitor?

[homefire]

No Arrows to any Caps. LOL I only drew lines to the FET and Coil connections.

""I get positive between the coil in and coil out (yellow connections) 150mV, that means i have two positive coil connections. Maybe a damaged damping resistor? Or maybe everything here is ok?
And its the right section of the circuit. I think the coil was not connected."" If you measured without the coil Then 150mV has to be the Voltage drop of the R9. Make all your measurements with Neg Lead to Neg side of battery as Reference. Your seeing the coil connections Positive because your referencing to the Neg of Battery. One side of the Coil is MORE Negative then the Other.

[BKY1337]

Ok, so do you think that my K157ud2 is damaged?
I have ordered 2 used ones from lithuania again.

[homefire]

Don't know. Check what is going in verses what is coming out.

[BKY1337]

I made this already. I have posted the voltages here , but i think i have measured it wrong. I need to measure inverted inputs + and - . I have only measured every pin with - at negative rail (GND). What should come out?

I need a simple testing circuit for the k157ud2.

[homefire]

Just Measure the input pins to Grd both inverted and Non. Both Op Amps. Measure the outputs as well. All Referenced to Grd Neg.

[BKY1337]

I have already posted this results here in the thread. I had pretty much everywhere around 6-8 V , but not at the pins 10 and 12, the multimeter displayed 0-300mV there.
It begins with 0 and the voltage rises to 300mV then it falls back to 0 and begins again to rise.

Look at my picture.

The pins 10 and 12 are not used by the circuit. I dont know which voltages i should have. None of the voltages was oscillating.

[homefire]

What were the Input voltages ? Out Put Voltages. Your Inputs can't be that high the Diodes limit it to around .5 Volts. Measure that from the Plus to input pins.