SPDR ( SURF PI DIGITAL REVISION )

[godigit1]

Hi Moodz.
If All your kits are not allready spoken for I would like to purchase one when you are ready.
Great job on this project.
Thanks

[moodz]

I have 10 of the V1 boards .... but need to make sure they work ;-)



This board is configured in "surfpi mode" ... ( no switchmode supply, "traditional" damping resistor .... I used a thickfilm power resistor but the board is spaced for a 5 watt vertical mounted axial type. )
However it does have the "autoswitch" front end.
There is one wire link ( my bad ... missed one track )
Other than that it should be good.

I did not socket the 18pin diff amp because I did not have an 18 pin socket ... doh.

we will see shortly .....

[moodz]

Step 2 ... fit the CPU (which generates the pulses for the negative voltage charge pump) and the tc4428 mosfet driver chips.



turn on the power ... it works ! No smoke.
CPU is running and negative voltage rail is up.

We can now fit the other chips ....

[moodz]

Step 3 ... fit all other chips and discover why 18 pin socket was not needed.

Doh ... the board layout somehow translated a 16 pin socket to a 18 pin socket. No matter ... a bit of solder surgery and it works. :-) Stand chip on its side solder pins 1 - 8 and then cross connect the other pins.

PCB will have to be revised. ( V2 ).

[Mdtoday]

Oops...but at least it works��

[moodz]

...ordered the V2 boards.

[Mdtoday]

Nice work Moodz

[moodz]

V2 boards arrived !

[Mdtoday]

Looking good Moodz,

Pretty good turn around..

If you don't mind saying, which board house are you using for PCB?

cheers

Mdtoday

[moodz]

Looking good Moodz,

Pretty good turn around..

If you don't mind saying, which board house are you using for PCB?

cheers

Mdtoday

Thanks Md ..... I use pcbway.com .... about $USD 3.50 each + $USD 25 shipping DHL ( 3 - 4 days ) to AU for ten, double sided colored, masked, silk boards seems reasonable. The quality is very good. I could save money by shipping the slower way :-)

[Mdtoday]

Thanks Md ..... I use pcbway.com .... about $USD 3.50 each + $USD 25 shipping DHL ( 3 - 4 days ) to AU for ten, double sided colored, masked, silk boards seems reasonable. The quality is very good. I could save money by shipping the slower way :-)

Excellent, I'll give them a try, thanks Moodz, much appreciated, my usual go to pcb house has almost doubled their pricing, so was time to use another...

Look forward to see how your new project goes, nice, well thought out little board...

cheers

Mdtoday

[moodz]

I have used them a few times ... good value so far .....

Here is the board loaded ready for first power test before pluggin in the chips ;-)

[Mdtoday]

I have used them a few times ... good value so far .....

Here is the board loaded ready for first power test before pluggin in the chips ;-)

[ATTACH]44928[/ATTACH]

Yes, they look pretty good, tried them with a PCB design today and will see how we go but from the look of it, should be fine.

Hopefully all good on the power up for you then...

cheers

Mdtoday

[WM6]

Here is the board loaded ready for first power test before pluggin in the chips ;-)

Nice "darkness" look!

Should be full success. Awaiting your test report.

[moodz]

thanks WM6 :-)

power tests passed .... no smoke.
connected coil ... no smoke.

Measured the flyback and out from the preamp ... excellent ... damped in 2 microseconds with sampling at 2.5 microseconds.
This version was built with the active damping and noise cancelling preamp so it achieves faster damping than the resistive damping model ( the pads are on the board for this version also ) which can only do sampling at 4 usec earliest if you are lucky.

Current draw from 12 volt supply is 180 mA

TX voltage is 5 volts ( can be changed )

PREAMP GAIN = 100

TX period = 80 usec
RX period = 80 usec