Tri-Negistor Questions!

[inverseroom]

I have this little pile of metal can 2N2222A's, and was looking for something to do with 'em...and naturally visited the Moosapotamus page for inspiration.  I ended up getting started on a Tri-Negistor.  I've already asked Charlie a couple of questions (which he answered with the usual warnings and caveats), but I figured I'd leave him be for a minute and pose a few to you all.

1) A lot of people here seem to have trouble running the Tri-neg on 9 volts.  Should I build in a power jack in case I need 12?  Or should the metal 2222's start negisting under 9, as Charlie's do?

2) A lot of people have complained that the oscillator pots only have any effect at the bottom of the travel.  I've got a few 10K's lying around and will give them a shot--anyone have any luck with these?

3) On charlie's wiring layout there seems to be a diode on a wire that is carrying positive voltage (??!) to ground on the output jack.  What ought I to put here?  I have a bunch of 1N400x's and assume they're the ones to use, but I'm not sure...

4) And where should ground be?  The back of the volume pot perhaps?

Thanks everyone...
John.

[moosapotamus]

I don't have datasheets handy at the moment, John. But, as long as you don't exceed the voltage ratings of the components you're using, an external power jack might be a good idea. Just make sure you keep the polarity straight, you know... tip neg or tip pos. :wink:

Also, regarding pot values, if the smaller values don't give the results you're looking for, you might also try putting a fixed resistor in series with a pot to get the resistance across the pot in the right range.

Good luck!
~ Charlie

[inverseroom]

Hmm, well...I just powered up for the first time on a 9v battery, and only osc 1 is working, and then only when all the switches are in certain positions, which I've already forgotten!  And I am getting A LOT of static otherwise (I assume from the other two pots).  Maybe I should go ahead and put 50K pots there?

This is perhaps not a good project for someone who doesn't understand what the hell he's doing...

[moosapotamus]

:lol:
... just kidding. Actually, that's how I built mine, one osc at a time. :wink:

~ Charlie

[Paul Perry (Frostwave)]

2222s aren't guaranteed to oscillate at 9V. Hell, they aren't guaranteed to oscillate at ANY voltage! but, looking at past posts & elsewhere, 9 is pretty low.
I'd try swapping one of the other 2222s into the working oscillator, that will show whether the threshold on the other one is above 9. And if I was committed to running off batteries, I'd think TWO 9v batteries (or, one and a doubler).

[Prive]

I have mine working at 9V but the pots are most touchy.
With 12 volts this thing really works!!!! Lots of noises imposible to achieve with 9.

Thanks Charlie!!!!!!!!!!!

Saludos, Marcelo.

[inverseroom]

I just got some power jacks in from Mouser, so I'll try sending it 12v over the weekend...or two 9v's if that doesn't work!

I think the static was from my poorly grounded Ruby Amp, BTW, not my mistakes in executing Charlie's design.

Or, for that matter, Charlie's mistakes in Charlie's design.  :lol:

[moosapotamus]

:shock: ...