Barracuda Legend Kit Problems

[Tim]

Cheers Koala. I just popped out and tried a 50K pot on threshold- problem solved! 8 inches on an Oz 5c, and getting my 1.7g of flour gold at 2 inches with the flouro light interference.
Now I'm gonna fiddle the delay & offset a bit and see if I can improve it.
I'll keep the pullup and offset mods in mind for my next Bara, but for now I can make this a workable enough machine to warrant a stem,handle etc.

Here are pics of my standardised design.

Thank you all for your input!!

Yes KT yours is right, and silly buggers like me keep asking stupid questions. You and the other Gurus are gems for answering them.

[kt315]

Welllll..... I'm getting really bamboozled here. Sooo many variations of schematic, it's like a game of Chinese whispers.

NO variations of schematics nowhere -!!! it's ONE and ONE is mine right. i had gave right schematic to people but the people want to be BLIND. mine is standart and this subject had closed on ages frontwards!

[Koala]

Welllll..... I'm getting really bamboozled here. Sooo many variations of schematic, it's like a game of Chinese whispers.
Correct me if I'm wrong, but 5534 pins 1&8 to 100K pot/22K/+5.
33K pull-ups on 40106 changed to 12&15K.
????????
Nnnn..yeah?
....but my problem is no audible threshold. Sensitivity does increase with threshold.
Before I do any of this, I will try LT1054&12.6max V input, different 40106&5534s.

I have offset balance already.

Can someone answer me this? If I change the 25K threshold pot to Q's recommended 50K, will that give me extra threshold range, without butchering the 27/39Ks?
Going over to the main thread and build sticky now to see if there's any updates.

Forget changing the board.

All variation of the board have good threshold. You must have something wrong. Better to fix the no threshold before modifying the board.

[Tim]

Welllll..... I'm getting really bamboozled here. Sooo many variations of schematic, it's like a game of Chinese whispers.
Correct me if I'm wrong, but 5534 pins 1&8 to 100K pot/22K/+5.
33K pull-ups on 40106 changed to 12&15K.
????????
Nnnn..yeah?
....but my problem is no audible threshold. Sensitivity does increase with threshold.
Before I do any of this, I will try LT1054&12.6max V input, different 40106&5534s.

I have offset balance already.

Can someone answer me this? If I change the 25K threshold pot to Q's recommended 50K, will that give me extra threshold range, without butchering the 27/39Ks?
Going over to the main thread and build sticky now to see if there's any updates.

[ripsdevala]

the only way I can see the 4001 fry is that it was installed backward. 7660's can get hot with 12 volts applied. It is only rated for 10.5 volts absolute maximum. You could try the S version or use only 7 cells.

... yes forgot to mention, I use 7660S 12v max, will try to replace it when I home, and Im sure there is no backward 4001 diode maybe one of them is dead and make a short. Will report later...

Thanks

[6666]

Just for the record mine is a TC660SCPA absolute max input 5.5v, and no sign of any warmth.
and HEF40106BP made by NXP, I think I got that from Jaycar.

When I wrote that, it did not seem right as it was a direct quote from the data sheet at alldatasheet.com, so rechecked it and their data sheet is just a generic 7660 data sheet, but having trouble finding the data sheet specifically for a TC660SCPA, but it must have a higher voltage input than 5v because mine runs at 13v no probs.

[Old cart]

Use LT1054 instead

that is a good suggestion.

[Old cart]

Thanks Old cart. My board is spotless and traces correct.Will check/change the thresh pot and have a squizz at the Rs there. I did notice the pullup Rs changed on the Alex version from earlier ones, so worth consideration. Although my 7660s are scpaz, I fear this batch are inferior, as my 40106s, so I will replace both when my new batch's arrive.
I won't cut and shut anything until I get a voltage converter that can handle 12.6v.

Thank you sir-sound advice, and a process of elimination for me to follow.

All my builds so far I use 3x18650s, with an on-board 4A charge controller(alongside batteries in pic above). Resistor The method in my madness is that they can be charged from any un-regulated 12v source. I have a 12v 1.5w solar panel mounted on my stem for constant charging, to extend battery life on long hunts, and charge while idle.

ripsdevala, I would hazard to say your 7660 needs replacing.

Look at the posts found in this thread

http://www.geotech1.com/forums/showthread.php?23009-Baracuda-Build-(silverdog-kit-Rev2)/page3

the pull-ups values have been changed as have the voltage they are referenced to. Plenty of good discussion there. You wil also find a new schematic further down that captures all the changes. But read it all. Even the last schematic has a 2.2M resistor in the threshold circuit. Later in the thread the value is corrected to 39 K as I recall.

[eclipse]

Use LT1054 instead

[Old cart]

Old chart I need a help, view days ago i fried diode 4001 closest to + and - battery,because i try to put three 3.7v li-ion battery 18650, Its dead and short, I already change the fried one with 4007 and work again, the problem is when i use 8 alkaline battery with 12+volt, the 7660 IC become hot, cant hold it more than 2 sec, its burn my finger, did I miss something, or other 4001 is short also.

Thanks

the only way I can see the 4001 fry is that it was installed backward. 7660's can get hot with 12 volts applied. It is only rated for 10.5 volts absolute maximum. You could try the S version or use only 7 cells.

[6666]

Just for the record mine is a TC660SCPA absolute max input 5.5v, and no sign of any warmth.
and HEF40106BP made by NXP, I think I got that from Jaycar.

[Tim]

Thanks Old cart. My board is spotless and traces correct.Will check/change the thresh pot and have a squizz at the Rs there. I did notice the pullup Rs changed on the Alex version from earlier ones, so worth consideration. Although my 7660s are scpaz, I fear this batch are inferior, as my 40106s, so I will replace both when my new batch's arrive.
I won't cut and shut anything until I get a voltage converter that can handle 12.6v.

Thank you sir-sound advice, and a process of elimination for me to follow.

All my builds so far I use 3x18650s, with an on-board 4A charge controller(alongside batteries in pic above). The method in my madness is that they can be charged from any un-regulated 12v source. I have a 12v 1.5w solar panel mounted on my stem for constant charging, to extend battery life on long hunts, and charge while idle.

ripsdevala, I would hazard to say your 7660 needs replacing.

[ripsdevala]

Old chart I need a help, view days ago i fried diode 4001 closest to + and - battery,because i try to put three 3.7v li-ion battery 18650, Its dead and short, I already change the fried one with 4007 and work again, the problem is when i use 8 alkaline battery with 12+volt, the 7660 IC become hot, cant hold it more than 2 sec, its burn my finger, did I miss something, or other 4001 is short also.

Thanks

[Old cart]

Anything and everything 6666. I'm about 300km from "The Triangle", so it's a case of having a machine for each purpose-I have 21 now counting the 'Cuda.
The emerald and diamond ring was found 3 days ago with the Surf. The slug,shell and 20c coin today with the Compass 94B.
This one would be a great project-simple and sensitive-but the coil may be tricky.
I finally secured a concentric coil for my GMT last week-apparently they are even more sensitive to sub-gram gold than the DD.
Mongolata goldfield is my closest, but my area here is a WW1 soldier-settlers district, and Paddle-steamer railhead, so I find things of interest nearly every swing.
An upcoming project is the Falcon MD20, to compliment the blacksand meter on the GMT.

Sorry.Off topic. Any ideas about my Bara threshold. Anyone?

Check for shorts between the wires going to the threshold pot, also on the pcb itself. Check to make sure the threshold pot is OK. Last check the resistors attached to it for correct value and operation.
The 40106's have been major cause for problems as have the 40106 pull up resistors.
But until you have the supplies all correct all bets are off.

[Tim]

Anything and everything 6666. I'm about 300km from "The Triangle", so it's a case of having a machine for each purpose-I have 21 now counting the 'Cuda.
The emerald and diamond ring was found 3 days ago with the Surf. The slug,shell and 20c coin today with the Compass 94B.
This one would be a great project-simple and sensitive-but the coil may be tricky.
I finally secured a concentric coil for my GMT last week-apparently they are even more sensitive to sub-gram gold than the DD.
Mongolata goldfield is my closest, but my area here is a WW1 soldier-settlers district, and Paddle-steamer railhead, so I find things of interest nearly every swing.
An upcoming project is the Falcon MD20, to compliment the blacksand meter on the GMT.

Sorry.Off topic. Any ideas about my Bara threshold. Anyone?