PI5 from ITMD

[Qiaozhi]

Thanks for that. I hadnt seen that one before. Easy to draw up small prototypes.

Actually, it's really good for large prototypes as well. It's the only way to get a good-looking layout, and to prevent getting lost in the maze of track cuts and jumpers.

[geoscash1]

Awesome, thanks for the link to DIY Layout creator Qiaozhi... I always do stuff the hard way or the "old fashioned" way, draw it by hand.... lol.. I will definitely give this
a good try out..

Question - What is the recommended coil for this unit since the revision or is it still the same as the original at 2.9uH/mH? I have tried using coils
for my surf/cuda and other detector boards I have but nothing seems to work right..

[Qiaozhi]

Question - What is the recommended coil for this unit since the revision or is it still the same as the original at 2.9uH/mH? I have tried using coils
for my surf/cuda and other detector boards I have but nothing seems to work right..

This version is designed to work with coils between 300uH and 500uH.

[geoscash1]

thanks, not bad

will see what i can do, maybe i will post first results next weekend
many thanks

p.s. i love your avatar it reminds me of my wife 12 years before

Right on bernte_one, will wait to see how yours comes out as well.... and thanks, she (avatar) is a beauty and has a very nice backside

Thanks Qiaozhi, good to know... my new board should be done soon, have a few resistors to route yet and then
will give her some juice and see what happens..

[geoscash1]

Ok, 3rd board built and still not working... Dang.... I think I'm done messing with this one at least for awhile, used up a pile a parts for 3 of them...lol...

Oh well, maybe someone else can get one built right and working..

[bernte_one]

after building pi1, pi2, and pi4 i am a bit disappointed
i suspect a bit more, i seems the Projects are so simple that they must go wrong or i have a Little brain disease
i build much bigger complexer Project with more succes
the Projects are concepts, but not prooven or field tested so far my impression

i go to build pi3 and pi5, but i think they will not be the big burner
my hope was to get some tiny machines for learning and for real hunting
at the Moment the are jsut for learning and waste parts

i hope that some more poeple try to optimize this Projects and make Videos for comparing results

[bernte_one]

the next days i got a new oszi hantekdso5102p so i will Analyse all mi pi Projects from itmd book and bring them to end

has somebody worked more on These Projects then myself, or i am one of the lonely idiots which made Projects from classic paper book?

[geoscash1]

Hey bernte,

Nope, your not the only one....lol... I am getting ready to give PI5 another chance, another try and see if this time I can get it working... for whatever reason, the minute I saw it in the book I knew it had potential, it just seemed like a good basic design that could be built on... So, back to the bench for another one... wish me luck...lol

p.s. did you ever get it working ? did you use the pcb draw I posted or did you use your own?

[geoscash1]

PI5 #4 - fried again

Can someone look this pcb over good and see if there are any mistakes. I used the new updated schematic from George.

Let me know what you think, it is not working and I cannot see what the problem is or figure out why. I have tried many times on this circuit.

Attached the schematic and new drawn pcb.

[WM6]

Did you check signal at pin3 of IC3 and then at collector of 2N3904?

[bernte_one]

will look this night for Errors, pcb looks clean so far
a short look on schematic and you will see that it would make sense to add an Option for a trimpot pulsewidth on the next improoved layout
IC3 NE555 but first it would be our Task to make this Basic Setup workable
last evening i etched pcb for baracuda and nes500
so my Equipment is still in range

could you upload gerber files of top and bottom layer i would adapdt this for sprint layout

btw wm6 is right
http://www.ecs.umass.edu/ece/m5/images/2N3904_pin_layout_S.jpg

and please name all parts on silkscreen like on schematic

connectors for Switch, power coil, headphones.. should be for clamping of rm5 (pinhole width)

irf9630 should have some more place for a heatsink


p.s. this 5minute timeout for wrinting sucks

[Polymer]

Geotech,

Hmmm, I just compared your schematic with the one I got from George and there is one difference :

Pin 5 (CONT) of IC3 (555) is NOT connected in my schematic!

The capacitor numbering is also different in mine, C6 I have twice!!!??? But C values are the same as in your schematic.

From what I have read about the 555, pin 5 should be connected to GND with 10nF when not used.

GEORGE, what has happened here

[bernte_one]

just an idea, i checked a web based pcb design there we can also order pcb with Option for assembly (maybe all resistor and ic sockets pre-installed)
easyeda.com pcb desgin, schematic design, circuit Simulation

[Qiaozhi]

p.s. this 5minute timeout for wrinting sucks

There is no timeout enabled on the Geotech forum. It must be a problem with your browser.
Have you ticked the "Keep me logged in" box?

[Qiaozhi]

Geotech,

Hmmm, I just compared your schematic with the one I got from George and there is one difference :

Pin 5 (CONT) of IC3 (555) is NOT connected in my schematic!

The capacitor numbering is also different in mine, C6 I have twice!!!??? But C values are the same as in your schematic.

From what I have read about the 555, pin 5 should be connected to GND with 10nF when not used.

GEORGE, what has happened here

The updated PI-5 schematic (sent to those that requested it) was created prior to ITMD Second Edition being released. The circuit posted by Geocash is from the book. Hence the slight differences.

If you're not using the control voltage input (pin 5) on a 555, you can add a small capacitor (usually 10nF to 100nF) to 0V to prevent intereference. I typically add the capacitor if the 555 is being used as a monostable, but it's not always necessary if being used in astable mode. Depends on the application. Here (in the TX oscillator) you don't need it, but you can add it if it makes you feel better.