Voodoo Main Discussion

[SilverSurfer17]

I plan on using this on my etrike and want the etrike to run on 72 volts but be able to use 12 for the detector off the same battery pack

[dfbowers]

I will check it out when I get a chance. It’s totally dependent on the resonant frequency of the RX coil. It will work over a wide range of frequencies as long as you can adjust your delay to cover the first cycle of the decaying sine wave. Also, the sample width needs to sample shorter than 90 degrees. If you check my previous post you can get an idea. I will take some measurements and post them up shortly..

I can sample immediately after the main clock and is adjustable out to 40uS with the current delay resistor. Sample width is 10uS

[6666]

I can sample immediately after the main clock and is adjustable out to 40uS with the current delay resistor. Sample width is 10uS

Thanks for doing that Don, its very helpfull, cheers

[Altair]

This need to be checked by "neutral eyes":

Well made Ivconic!
I have checked your work and found these points to fix on PCB:
1. Q1 is marked as 327; it should be 64
2. Q1 has emitter and collector inverted
3. R34 is missing
4. C14 value must be 1nF
5. Connection between R24 and R27 is missing but I will suggest to take in consideration the variant showed at post #942
6. Capacitor value between pin 5 of U1 and 0V is missing; it's should be 10n (on schematic this capacitor is missing)

Test points are missing on schematic.

The rest seem OK!

[ivconic]

Well made Ivconic!
I have checked your work and found these points to fix on PCB:
1. Q1 is marked as 327; it should be 64
2. Q1 has emitter and collector inverted
3. R34 is missing
4. C14 value must be 1nF
5. Connection between R24 and R27 is missing but I will suggest to take in consideration the variant showed at post #942
6. Capacitor value between pin 5 of U1 and 0V is missing; it's should be 10n (on schematic this capacitor is missing)

Test points are missing on schematic.

The rest seem OK!

Bravo! Good eyes!
Explanation:
1. I put BC327 because is easier for me to obtain BC327/40 than MPSA.
2. BC327 pinout is CBE while MPSA is EBC.
(MPSA is darlington, BC327 is not. But it will do the job just fine there.)
3. Correct! I take this as first mistake.
4. Correct! This is second mistake.
5. Correct! Third one.
6. I asked about it at the time i drawn schematic, since it is missing from the previously posted schematic. I got no answer. Yet i "reserved" a space for it on pcb.
...
3 mistakes on pcb... not bad at all for me lately! Since i am completely out of focus. It is quite "normal" for me lately to make several mistakes while drawing pcb.
Later on in process of soldering and testing; usually i locate the mistakes.
But it is better to start without them at all.
I will try to correct those on existing draw and post final correct one.
Thanks!

P.S.
In meantime corrected:

[ivconic]

... but I will suggest to take in consideration the variant showed at post #942...

Done;

[ivconic]

Small notice:
1) In case of 9v battery; U30=7660 and D6=7V5, (U30 can be 1054 too)
2) In case of 12v battery; U30=1054 and D6=9V1.
...
So far i made many Barracuda's and all supplied with 9V, so 7660 is working there pretty cool and correct.
Lately i made Voodoo, supplied with 12v, for testing purposes i put 7660 and it gets hot within seconds.
Probably would die if left longer. So 1054 is must if supply is 12v and over.
I left options in schematic and pcb for 9V and 12V supplies.
7660 is peanut price while 1054 is pretty hot!
Since this is only small testing circuit; i don't see much of a sense to waste money before is tested and proven good.
So i plan to use 7660 and supply it with 9V. If i like it; later on to use 1054 and supply it with 12V.
...
Voodoo is the main aim here. I will use DBowers idea, make it, test it and see what will come out of it.
But all this in service of making final success with Voodoo.
Changes in code are mandatory. Mostly related to audio behavior.
Non motion binary audio is first subject to change.
Logically: small changes on circuit are needed too.
Instead of simple "pulling" (switching) the audio; VCO controlled by PIC is desirable.
RA4 should provide PWM output "mapped" to signal amplitude... for example.

[Altair]

Only three mistake is a very good result!
Now it can only goes well!


Regarding Voodoo, I agree with you about to avoid the binary audio.
PWM could be an option but also a simple R-2R DAC network could do the job.

[ivconic]

Only three mistake is a very good result!
Now it can only goes well!


Regarding Voodoo, I agree with you about to avoid the binary audio.
PWM could be an option but also a simple R-2R DAC network could do the job.

Yes that would be even simpler solution, with engaging several spare pins.
I am just looking at schematics and i see RA2, RA3 and RA5 are unused.
Quite enough!

[Altair]

About last Ivconic schematic, It may be that C27 not need to be connected to pin 3 of U1 but instead to the Q1 collector.
Dfbowers, could you check if it's true?

[Altair]

Moreover, to do delay line with smith trigger the pull-up resistor must be connected to the input gate pin, not at the output.
Referred to the schematic:
-R48 must be on pin 5 of 40106;
-R22 must be on pin 1 of 40106;
-C25 and the third gate of 40106 don't should be needed if modification at post #956 will be made.

[dfbowers]

Moreover, to do delay line with smith trigger the pull-up resistor must be connected to the input gate pin, not at the output.
Referred to the schematic:
-R48 must be on pin 5 of 40106;
-R22 must be on pin 1 of 40106;
-C25 and the third gate of 40106 don't should be needed if modification at post #956 will be made.

Yes.. Good catch! Last evening I caught the same error. You just beat me to the post. I started moving everything off my breadboard to a protoboard to take our experiment to real world testing. I found a few other minor errors too.. Wrong pin labels, and a cap showing connected to rail voltage instead of ground. I changed a couple of resistor values too but nothing major. The basic scheme is unchanged.
Thanks.
Don..

[ivconic]

My pcb arrived half an hour ago.
So...
Would be good if you use this free software: https://www.expresspcb.com/
(Classic or Plus, the same)
and apply all the changes by your own , using schematic file i posted several times here.
Software is easiest possible to use for drawing and editing.
You need only 5 minutes to adapt on using it.
Goal is to have here most proper and accurate schematic.
With pcb that arrived now; i am not sure what to do?
Should i solder the components like on my pcb draw or should i make further "surgery" on it?

[ivconic]

... I found a few other minor errors too.. Wrong pin labels, and a cap showing connected to rail voltage instead of ground. I changed a couple of resistor values too but nothing major...

Actually you are saying that schematic i posed is having more errors? Therefore the pcb too?

[dfbowers]

Actually you are saying that schematic i posed is having more errors? Therefore the pcb too?

The only thing I caught of any significance was what Altair mentioned. I will double check..