Help to design a PCB for my PI design!

[okantex]

Wellcome Moodz,

what about your designs depth results. air test results for coins, cola coke..etc.
regards

[moodz]

initial results.

Wellcome Moodz,

what about your designs depth results. air test results for coins, cola coke..etc.
regards

Well the design is not finished yet.

I am working on the descrim and earth field cancellation.

However this "single channel" model can detect a dime sized coin at 30 cm.
A fist sized nugget at 55 cm and a frying pan at 1 meter.

Thats why I need descrim as I dont intend to dig a 1 meter hole for old frying pans

[night]

hi 1843 schematic problem Q9 emiter connect to batt - top sik pdf Q9 collector batt - ? and Q2 emiter and collector ? schematic Different top silk pdf Different and R3 4k7 schematik 547 collector base connect topsilk pdf not connect r3 557 emiter and base connect Which one, correct, schematic our top silk pdf?

[1843]

Hi, The schematic is OK. Correct your pcb regarding that.

Thanks,
1843

[1843]

hi 1843 schematic problem Q9 emiter connect to batt - top sik pdf Q9 collector batt - ? and Q2 emiter and collector ? schematic Different top silk pdf Different and R3 4k7 schematik 547 collector base connect topsilk pdf not connect r3 557 emiter and base connect Which one, correct, schematic our top silk pdf?

Hi Night, The MOSFET is laid out wrongly! And that caused your Q9 frying! as I said the schematic is right...

[1843]

Night,
The layout of gate driver circuit (including Q9, Q2, Q3) is ok. Don't change R1 to 330 ohms or any other values.
The drain and source of the MOSFET need to be swapped on the PCB.
You may have burned your Q9, Q2, Q3. So change them.
On the components side, Q2 and Q3 are labeled wrongly! they need to be swapped too.

[night]

hi 1843 schematic According to pcb Correct? why Q9 collector pin pcb connect to batt - schematic connect Q9 emiter pin batt- My head interfered Which one, correct, schematic our pcb Q9-Q2-Q3 I checked strong. I connected to According to schematic..

[1843]

hi 1843 schematic According to pcb Correct? why Q9 collector pin pcb connect to batt - schematic connect Q9 emiter pin batt- My head interfered Which one, correct, schematic our pcb Q9-Q2-Q3 I checked strong. I connected to According to schematic..

See the BC547 pinout:


It's ok in both the schematic and the pcb.

[Rov]

Yes night ,check your pinouts carefully,the circuit does work,as for the schematic ,this is layed out in schematic blocks format for sections. if u used to a complete integrated single schematic,can lead to confusion ,what goes to what ,an your eye loose track. an one error an ,no go.
i have trouble only with coil! an performance .I no good with coils! yet!an stupid mistake of own with lcd screen wiring,my own fault!

[Unregistered]

new pcb

i wanna build one, pls send new pcb..................
tank u

[Mustafa]

sorry, wrong post
deleted message

[okantex]

Hi All ,

why there is no movement at this topic,
is not there anybody who deals with this design,
I wonder test results.
does pcb works good ?
or does it still need improvements and corrections.
according to mails there must be correct pcb on the forum but it is missing.
regards
okantex

[ashkelon]

what's the result ?

[smity]

The final version of the scheme, firmware, PCB ... please. We'd also like to read about the characteristics and tests.

[dfbowers]

What an interesting read this thread is ....
I have just registered with geotech.

Here are some photos of my version attached ...

Note the careful layout

Oh and I made some changes ... to remove alot of noise issues the coil feed line passes through a bifilar "balun" ... it does not affect the pulse.
ie reduces the unbalanced antenna effect of the feedline. ( I used to be an RF guy )

I use a CA3130 as first amplifier ( FET inputs ... much higher input Z )

The uP is a DSPIC 30F4012.

A switch mode supply provides 16 volts for the analogue no sync.

A 12 volt batt pack from a $15 dollar drill powers the circuit for 4+ hours.

"Manhattan Style"! I built a shortwave radio this way once and it actually works quite well. At least you have a good ground plane!
http://www.piclist.com/techref/pcb/manhattan.htm