Hammerhead PI SMT on mine board

[kt315]

hello GeoTechers,

much of you get from me SMT PCB's and maybe you need in some help from my side. so I open this new thread for you.

regards

Anatloy

[Silver Dollar]

Hi are you selling the SMT PCB's? I know you were giving them with a DP purchase...

The SMT will fit in a much smaller case, good for underwater detectors. I have a few
coils ready and am thinking about the rest of the detector now...

[kt315]

[Silver Dollar]

I found some missing grounds. Do you have documentation showing them all?
I will Fire up one board tomorrow and want to double check everything first.

[kt315]

Silver Dollar, on stage of manufacturing was losed some pouring. not my fault. yes, you have to do some connections, I hope it will not so difficult to add.

[kt315]

also, there is absent track to a pot. actually if the pot has one line position pins.

[kt315]

hhc1_shablon.pdf

[kt315]

now about R10, 1 Ohm, in SOURCE pin of IRF740. SMT power of the resistor is very small, if you will encrease PULSE WIDTH to more value, R10 maybe burn.
ie for 50us this is maybe good and R10 will be not blow, however onetime I got a problem that playing with board R10 was burnt.

so you have to remember about this. I did change R10 on 0,25W ordinary resistor excluding this unwanted factor in future. look at the pics.

[Silver Dollar]

Yes it is no problem to fix, I missed the grounds for the regulators.
So thanks for the picture!

I thought of putting a standard resistor in for R10. I'm going with a
fixed 75us so it might be necessary to change it out.

I'm going for super tiny and a waterproof case to use in the water.
I changed the preamp to dual stage and built a bank of caps for the
1000uf to keep it small.

Pictures;

[Silver Dollar]

Hmm it seems I got some TC7660C's that only work to 10.5V;

MICROCHIP

The TC7660C is a charge pump DC-to-DC voltage converter with supply voltage of 10.5 V, available in a SOIC-8 package

[Taktyk]

The TC7660S is a charge pump with supply voltage of 12V .

[Silver Dollar]

Well it seems some varieties only go to 10V on the input. I'll try lowering the voltage to see
if that's why I have no +5v.

[Silver Dollar]

Well it turns out I installed a couple of chips backwards so that killed my 5v.
I turned them around and now all is well for the power at least. Tomorrow I
will test all the pulse widths and then install the FET and see if it works!

[bernte_one]

hello Silver Dollar,

some News on your Project?

[Silver Dollar]

Well the lab is shut down for the time being. (We are in the middle of a move).
I still haven't gotten a PI working. I did try relaying out the Mini Pulse in SMT...