Help to design a PCB for my PI design!

[zenit52]

Hi 1843,

Thanks from you,
I want design a PI MD by avr atmega too,
for design PCB for your schematic I have a nice idea..
Dear 1843 you can use a software named: PCB Wizard 3.50 Pro

you just draw your schematic in software and then automatically this software turn your schematic to PCB !!!
This is a nice way ................isn't ?
If you wish i can send you cracked version of this software ...

Have a nice day....

[Eugene52]

Help to design a PCB for my PI design !

Hi 1843,

Thanks from you,
I want design a PI MD by avr atmega too,
for design PCB for your schematic I have a nice idea..
Dear 1843 you can use a software named: PCB Wizard 3.50 Pro

you just draw your schematic in software and then automatically this software turn your schematic to PCB !!!
This is a nice way ................isn't ?
If you wish i can send you cracked version of this software ...

Have a nice day....

Nice work everyone !!!! looks like a Good Design , remind's me a little of Barracuda P.I....Anyway , I am also interested in the PCB Wizard 3.50 Pro "Full-Version" , please email to me at [email protected] . Thank-you .....maybe later someone will post the simple AVR programing files for this nice P.I. circuit !!!.................Regards...........Eugene52

[1843]

Hi 1843,


you just draw your schematic in software and then automatically this software turn your schematic to PCB !!!
This is a nice way ................isn't ?
.

No, automatic PCB's are not good... The software does't know where to draw the paths for noise immunity...
and you will end up with a noisy PCB!

Nice work everyone !!!! looks like a Good Design , remind's me a little of Barracuda P.I....

Yes, the preamp is from Barracuda! I maked this schematic by Paint... each part from a different PI...


Best regards,
1843

[1843]

maybe later someone will post the simple AVR programing files for this nice P.I. circuit !!!.................Regards...........Eugene52

The problem is PCB at the moment... I give you the best program beating any PI's!

1843

[Fred]

No, automatic PCB's are not good... The software does't know where to draw the paths for noise immunity...
and you will end up with a noisy PCB!1843

Exactly!
But unfortunately i am not too good for noise immunity in my designs (see the Relik hawk, maybe a nice looking PCB but some flaws in noise perforances), i also don´t have much time now, but your project is nice.
Good luck,
Fred.

[zenit52]

Hi Eugene52,

Please check your email, I will contact with you ...
There is one other program from this company to simulate a circuit
it is named: Livewire 1.11 Pro

it is very simple and clear to test a circuit...
I have cracked version of this software, too
if every one want it, don't care, just tell me...

With best regards... zenit52

[1843]

Hi 1843,

really nice work. Looking forward to more details.

Aziz

Hi Aziz,
See the 1N4937 in series with the MOSFET. It works great! 600V...15pF...fast enough...

1843.

[bbsailor]

Hi Aziz,
See the 1N4937 in series with the MOSFET. It works great! 600V...15pF...fast enough...

1843.

1843,

The 1N4937 with 15pf of capacitance helps to isolate the coil circuit from being affected by the MOSFET full capacitance and should allow a higher value of Rd than the same circuit without the diode. The higher Rd value will increase the slope (more vertical) of the current discharge Time Constant (TC) to better stimulate small, low conductive targets.

What is the actual inductance of your 19 cm, 27 turn coil and the adjusted value of Rd for minimum delay? What is your minimum delay?

Have you tried a larger coil yet?

Thanks

bbsailor

[1843]

1843,

The 1N4937 with 15pf of capacitance helps to isolate the coil circuit from being affected by the MOSFET full capacitance and should allow a higher value of Rd than the same circuit without the diode. The higher Rd value will increase the slope (more vertical) of the current discharge Time Constant (TC) to better stimulate small, low conductive targets.
Yes! I observed the results after using the diode.

What is the actual inductance of your 19 cm, 27 turn coil and the adjusted value of Rd for minimum delay?
The inductance is about 380 uH and the Rd should be around 600 ohms.

What is your minimum delay?
The delay is set to 15 us for the small coil.

Have you tried a larger coil yet?
No, I can't test larger coils indoor.

Thanks

bbsailor

Best regards,
1843

[Aziz]

Hi 1843,

Hi Aziz,
See the 1N4937 in series with the MOSFET. It works great! 600V...15pF...fast enough...

1843.

glad to see, that you have found a better diode than the 1N4007. Even it is rated as a 1A diode (RMS value), it can withstand more current flow in pulsed operation. The forward drop voltage of 1.2 V is low enough.

If you like to have 12% more depth, then try the following:
doubling the coil voltage from 400 to 800V. Take the STx11NM80 (x=P, W, F, B) MOSFET (800V, 0.4 ohm, 11A). The diode 1N4937 could probably work further. If not, take the STTH812D (1200V) or 1N4007 if you can't get the ultra-fast diode.

The damping will be finished earlier due to high voltage. The target stimulation will be increased but signals only available, if you sample earlier.

Aziz

[Aziz]

Hi 1843,

another improvement is to increase the 1k resistor going to the anti-parallel clamping 1N4148 diodes. Increase this to 5.6k (or 6.8k) and adapt your damping resistor value to this change. The series clamping resistor has less effects during the high voltage clamping period (until ~0.7 V) and you can sample up to 2 µs earlier with higher target signal levels.

Aziz

[Beav]

Hi 1843.
I've been designing cct boards for 13 years and have experience in analog, digital, high-speed and RF layout (2.4 GHz is the highest freq layout I've done).
Perhaps I might look at your schem and study it a bit.
I'm getting married this year and don't have as much time as I did have in the past
but I'll see if I can estimate a time and get back to you.

Yes, I still layout circuit boards for a living...doing one now at work @ 2GHz.

Beav

[1843]

If you like to have 12% more depth, then try the following:
doubling the coil voltage from 400 to 800V. Take the STx11NM80 (x=P, W, F, B) MOSFET (800V, 0.4 ohm, 11A). The diode 1N4937 could probably work further. If not, take the STTH812D (1200V) or 1N4007 if you can't get the ultra-fast diode.

Aziz

Thanks for your ideas;
One of my purposes to design this PI was to use ordinary and easy to get components so that everyone would be able to build it at everywhere. So further developements are possible...
Now I really need a good PCB to continue developing the firmware.

Hi 1843.
I've been designing cct boards for 13 years and have experience in analog, digital, high-speed and RF layout (2.4 GHz is the highest freq layout I've done).
Perhaps I might look at your schem and study it a bit.
I'm getting married this year and don't have as much time as I did have in the past
but I'll see if I can estimate a time and get back to you.

Yes, I still layout circuit boards for a living...doing one now at work @ 2GHz.

Beav

That's very good if you design the PCB. I hope you get enough time and design it in a few weeks.


Best regards,
1843

[Qiaozhi]

Hi 1843,

In the photo of your prototype PCB, there are 4 control knobs on the front panel, but there are 3 variable resistors shown in the schematic. I can only see the volume and contrast controls, and the offset-balance (which is probably the preset). What are the others, and where are they on the schematic?

Also, there are 5 switches (not counting the on/off switch) but I cannot see these on the PCB. Or are they jumpers?

[1843]

Hi 1843,

In the photo of your prototype PCB, there are 4 control knobs on the front panel, but there are 3 variable resistors shown in the schematic. I can only see the volume and contrast controls, and the offset-balance (which is probably the preset). What are the others, and where are they on the schematic?

Also, there are 5 switches (not counting the on/off switch) but I cannot see these on the PCB. Or are they jumpers?

Hi Qiaozhi,

You're right. The panel and the prototype PCB are from a German PI (Minediver) I had made before.(and due to bad performance it was hammered!!!)

In my PI, settings are done by the 5 switches (push button) that they wrere not connected when I taked the photo.


Best regards,
1843