SBG-PID

[6666]

Hey 6666
did you manage to get it running?

Hi Not yet I discovered a problem with the PCB just trying to sort out whats going on.

[nickel_n]

Hey 6666
did you manage to get it running?

[ivconic]

Ivconic, when you laid out the PCB which schematic did you use ?, thanks.

[6666]

Anybody made it yet?
Any video?
I am too busy in this period, unfortunately i can't have time to pay on this.
But i would really like to see if somebody make success with this detector.

Ivconic, when you laid out the PCB which schematic did you use ?, thanks.

[bernte_one]

have several pcbs here, i run out of time and interest
so i offer pcbs europe wide

[dbanner]

Good on you for catching that. I hope one day to return to work on this circuit.

[6666]

Here is the story
On the SCS schematic, he shows capacitors C11 and C12, they are across + battery and the new - voltage
with out C12 220uF the power supply oscillates, this oscillation wave form now appears on the + and - 4 volt voltage rails, and destroys the TX 555 pulse out.

On the Ivconic schematic he has drawn these two caps c11-c12 as C23 and C24, but seems to have omitted them from the PCB layout, or at least I cannot find where they go.
To fix this, I have soldered a 220uF cap across U5a +and - rail and the oscillation has stopped the rails are now clean DC and the pulse from the TX 555 looks ok
U5a is a rail splitter and produces + and - 4 volts

If you make this circuit make sure that the capacitor is in the circuit, and at least 220uF


( As a side note I modelled this in spice, (crash coarse cannot believe it worked ) how the heck does spice know the power supply oscillates with out the 220uF cap across it ? )

[6666]

I think I have the answer to this power supply, too late now

[6666]

Is anybody good at spice ?, if so would you mind having a go at the power supply please, I am getting a strange triangular wave shape at pin 3 of the 062 op amp with the op amp out of circuit, thanks.

Well blow me down after more hours of trying spice, I think I got it to work, and I can see the same crazy triangular wave shape at pin 3 of the 062 op amp, in spice, amazing.
Dont know why this wave is there but it makes the out put of the TX 555 look like crap

[6666]

Is anybody good at spice ?, if so would you mind having a go at the power supply please, I am getting a strange triangular wave shape at pin 3 of the 062 op amp with the op amp out of circuit, thanks.

[6666]

Hello SCS are you still here ?.
I was just looking at your timing diagram
there is a delay of 27 microseconds between the TX pulse and first sample which is fairly long
just so I understand your ground balance design a bit better.
What type of metal detecting are you using this design for what type of soil are you searching in ? thanks.

[ivconic]

Something like that. I lost a tooth in the lower jaw though, so i exercise now how to hide it with a lip.
The advantage of this situation is that now i can fire up pretty juicy spit, without separating the jaws!
Sort of the "invisible" weapon! Things are pretty interesting in the highlander life!

...
As for the SBG-PID; i am really looking forward for positive reports from other members: so i to start it all over again.
...
No hill billy smiley?

[dbanner]

[ivconic]

So maybe we should abandon our hybrid cars, and got to Walmart in a horse drawn buggy? To buy stove lacquer and window glass?
I'm just kidding,

Funny techniques we are recalling here were used long time ago, back at the '80s and '90.
Of course i am glad to have much better conditions now.
But from time to time i turn to some of the "old school" technique when i want to skim check some prototype or don't have time to wait regular pcb make.
Especially in my case this can be a problem sometimes, since i live out of urban area. Sort of mountain hill billy i am. (recently lost front tooth so i only need banjo)

[dbanner]

LoL, He is special in many ways;-))) But you are spoiled by the nova days technologies for sure :-P. Again no offense, just imagine that no internet and forums, so the only person who can help me with direction or advise was my father or the radio club manager. We have an old russian tube oscilloscope there(weighing some25kg), bench power supply and that it was. One 8 bit computer used mainly for CCTV, pocket radio(RTTY) and training the Morse code. That is where i see for the first time pcb design software in action. Even the permanent marker at that time was a luxury from the "rotten capitalism". Only few have it, instead i use black stove lack and Fecl or Hcl for etching with mixed results. True many of those got to the bin but almost equal quantity produce results.I still have somewhere my automatic keyer done that way. Sorry for the offtopic, just nostalgia i gues.

So maybe we should abandon our hybrid cars, and got to Walmart in a horse drawn buggy? To buy stove lacquer and window glass?
I'm just kidding,