Where is my Voltage?(Trouble)

[pedrete]

I ordered a Silverdod Rev DMinipulse kit.
I followed the manual.
I Build without scope.
I build and I succes.
As a coil i builded one "basket coil".
--Air Probe OK--

Than I install all in a "tuperware box".
As my battery pack connection i choised a 6,5mm Jack. Oh! That was a problem!

Wery quickly i realised, and i put a switch betwen the battery and the connection point.
But, Something went wrong.

IF I connect my battery again to the board, there is a voltage drop, and i get only about 0,7V in the power suply line. (Without boad connection is about 13,8V)(acid-lead-full charged-aku)
Well, i quickly checked all components and there is Not any owerheating.
I mesured that down, and the current comsumption is about nothing.

Any idea?

Sorry for my "english".

[geoscash1]

I have the same issue except mine is in the +5 line somwhere. Replaced everything on that line with my own personal parts supply and it is still the same, +0.71v output from 78l05.. im about to take a hammer to this thing...in fact, it would almost make it worth it, all the frustration it has been...

[6666]

If you are going to wreck it, try starting to isolate the +5 line pcb track, and try and see what is dragging the voltage down

[Qiaozhi]

I have the same issue except mine is in the +5 line somwhere. Replaced everything on that line with my own personal parts supply and it is still the same, +0.71v output from 78l05.. im about to take a hammer to this thing...in fact, it would almost make it worth it, all the frustration it has been...

As you can see from the completed projects thread (and from KRinAZ's very interesting experiments) the MPP is a known-good working detector.
Put your Mr Spock head on, and try to debug the problem logically. Just ask yourself: "How hard can it be?".
Also, do as 6666 suggests, and isolate the +5V PCB track to prove whether the fault is on the supply side, or something is shorting out the 5V line.

[pedrete]

Hi to All,


after many try I solved the theme:


A “short” is produced on the battery in the moment when Jack is plugged to connector. That I already fixed in the first moment. But....


First “shorts” actually have burned out a poor solder inside the Jack connector. Not at all, there was a kind of flux-glued could contact, that at the point give correct voltage with a meter but was not able to carry any current.


I checked, and re-checked, I have changed whole voltage regulators zone.


The bulb shinned in my head as I have seen that the circuit worked well on a lab-power-supply but show problems with a battery.


Now the detector work fine (as it also did on-the-table).


I got one euro coin from about 12-17 cm deep in sand (inland sand -no salt at all) and fine hair clip from about same deep.


I am satisfied.



Thanks for help.

[Qiaozhi]

Now the detector work fine (as it also did on-the-table).

I got one euro coin from about 12-17 cm deep in sand (inland sand -no salt at all) and fine hair clip from about same deep.

I am satisfied.

Thanks for help.

If you attach some photos of your detector, I will add you to the Completed Projects thread.

[pedrete]

If you attach some photos of your detector, I will add you to the Completed Projects thread.

Yes, sorry for poor pictures quality.

You folks can see the solution for a PVC pipe extension of a crutch and that problematic power line with a switch between battery and connection jack.



More to say, that my new Inductance meter, recently arrived from Hamburg (there it come from China), say 1mH (1000uH) and 2.4Ohm. It have 25 turns (5x5 spider coil from this forum) of 0.5mm enameled cooper wire. The coil is 22.5cm between coil centers. ...it works good.
It is dry summer here in Europe this year and many times i´am lazy to dig so deep.



Nice kit.