PI5 from ITMD

[geoscash1]

I'm still interested as well, just haven't had time to get back with it. So far haven't had much luck. Ive built 4 and have 4 not working. The last one was the best effort
and it is cooked with multiple parts fried.

Was waiting to see if bernte_one could get his going but it looks like he is in the same boat as me, lots of parts used up without any luck in a working model so
hesitant in wasting more parts and time on it..

[Patrick]

and pin 8 (VDD) to IC1.

[Qiaozhi]

Hi where do pins 7 and 14 go on IC4

pin 14 (VDD) goes to +VB
pin 7 (VSS) goes to -VB

[6666]

hello friends,

some update, i hope i done not much wrong so i think i am ready with pcb and my nerves
pcb is based according to schematic on posting nr 39
i am not sure if i done all right on audio section (Q5)
[ATTACH]35023[/ATTACH]

Hi where do pins 7 and 14 go on IC4

[Qiaozhi]

if somebody has time and can make a look over my layout to proove it
i would do a test build

but i will do no more work on it if there is no interest, i have fired up to much parts in last time to the itmd Projects

maybe this Sub board isn´t popular enough
can´t understand why no one of These more skilled user here watch this Project
there is more interest in baracuda and surf pi

but if we can make pi5 working it can be the next favourite Project (simple, not many parts....)

At the moment I'm snowed under with real work, but I do plan to get this going for you.
I have the original circuit here (and it does work), but you'll have to give me some breathing space.

[bernte_one]

if somebody has time and can make a look over my layout to proove it
i would do a test build

but i will do no more work on it if there is no interest, i have fired up to much parts in last time to the itmd Projects

maybe this Sub board isn´t popular enough
can´t understand why no one of These more skilled user here watch this Project
there is more interest in baracuda and surf pi

but if we can make pi5 working it can be the next favourite Project (simple, not many parts....)

[WM6]

Interested, if it is working for you?

[bernte_one]

no more interest?

[bernte_one]

hello friends,

some update, i hope i done not much wrong so i think i am ready with pcb and my nerves
pcb is based according to schematic on posting nr 39
i am not sure if i done all right on audio section (Q5)

[bernte_one]

made my next steps
just some missing resistor and battery connection (have to set some bridges)

[6666]

For what its worth, when I was messing around with Davor's ground balance cct, I found those 4011's to be a really stropy chip to toggle
you needed a good full +-5 v supply and pulses had to be spot on.
try a cd 4093 if you have one

[bernte_one]

hi geocash,
i work parallel with you on a working layout
if you are ready with soldering try to find out where machine does not work

if you look Diagramm you can mention the circuit as a block desing
first check the power supply (Diodes right way, Elkos right way)
does all what Needs power get it + /- / vgnd - measure it with multimeter
then the pulse Timing block - does the circuit produce any pulse (which frequency , width ?) but you Need oszi for this
then the delay part / amplifier block/ pulse damping after that the Sound genenarator block at Input and Output

maybe it is time to figure out how all parts work togehter, im noob in elektronics for sure but if i dont understand i look how it should work in theory and measure if it works also in practice

often it is a trivila think like a missing Connection or a loose contact on a braoken i socket or defect part
but sometimes the calculation in theory wasnt right an the scheme has to be modified

[Qiaozhi]

I wish or am hoping George will chime in with some good details and build info for this project. It really has no detail in the book and the new schematic is different than the original book one (which was an incorrect version).

There are no constructional details in the book because it is a bonus circuit.

At the moment I'm completely swamped with real work, as I'm trying to complete an important project. Hopefully in a few week's time I might have some free time. Maybe we could turn this into a new project. Please be patient .....

[geoscash1]

Geoscash1,

Can just about smell the scent of your "resistor roast" here ... It sure does linger on for a while.

Have you found the cause yet?

What is the resistance of the speaker you used?
Looks like your transistor switched on and stayed on.

I'd try putting a resistor in series with the speaker to say 330 Ohms to limit the power to ~30 mA. Use at least a 0.3 Watt resistor for that.
It would give you ample time to measure & possibly listen to whats going on, before anything could go smokey bear.

I've got all the parts for the PI-5, but have to breadboard it, hopefully soon.

I appreciate your pioneering on this!

Hi Polymer,

No, I haven't messed with it since yesterday and still haven't figured out the issue. The speakers I use are 1-1/4" - 8ohm/0.5watt, little guys and they seem to work well with all my other builds.

I was thinking about that yesterday, maybe adding a resistor but just haven't been back to the bench yet to mess with it.

question, If the transistor is staying on wouldn't that be because of the 1.2k coming off the 4011 pin 10 output to the trimmer/pot connection at R16?

I wish or am hoping George will chime in with some good details and build info for this project. It really has no detail in the book and the new schematic
is different than the original book one (which was an incorrect version).

IMHO, this design or concept seems to me to have good potential but the lack of info on it is quite a hold back especially for some of us builders with no engineering experience other than this site.

I really do suck at difficult math and I know that most of this requires some good skill with figuring out equations and such, not to mention I cant seem to remember from one day to the next anymore...

I have been studying the parts and how they interact and relate to each other but this one quite a bit different to the other things posted and is sort of like a comparator circuit.

Anyhow, thanks for the advice, I'll try the resistor in series with the speaker after I replace the 3904 and R17 again and go from there. It seems I have no oscillation now so not sure what has happened, or I get no wave forms on my scope now so something is amiss somewhere else too...

p.s. yea, that smell is definitely something that lingers and those little darn parts can leave blisters on fingers too...

[Polymer]

Geoscash1,

Can just about smell the scent of your "resistor roast" here ... It sure does linger on for a while.

Have you found the cause yet?

What is the resistance of the speaker you used?
Looks like your transistor switched on and stayed on.

I'd try putting a resistor in series with the speaker to say 330 Ohms to limit the power to ~30 mA. Use at least a 0.3 Watt resistor for that.
It would give you ample time to measure & possibly listen to whats going on, before anything could go smokey bear.

I've got all the parts for the PI-5, but have to breadboard it, hopefully soon.

I appreciate your pioneering on this!