2N2222 flip?

[Here Lies The Fire]

So how would you go about flipping two 2n2222 transistors with one switch?
(flipping the tabs toward and away from the dots.)

hijg.jpg (97.13 KiB) Viewed 3295 times

do you just route the middle lead to the other side or do you have to switch all of them?
aka are the emitter and collector sides interchangeable?

[culturejam]

You could probably do it with a 4PDT toggle switch. But it would be a giant wiring mess. You'd leave the bases as is, and flip/flop both sets of collectors and emitters.

But that would only be able to swap both sets of leads at once. So you couldn't flip one but not the other. For that you'd need a pair of DPDT switches.

[aussy]

I asked the same question (for the same purpose) last week

[culturejam]

I asked the same question (for the same purpose) last week

The issue with this diagram is that you are only swapping one lead on each of the resistors. What the OP is talking about is swapping two leads on two transistors.

Can you give some info on how you used that setup to swap transistors?

[aussy]

Hm, thought that wiring swaps between two sets of components. I didn't actually do this myself, just figured it worked. Guess its back to the drawing board?
Try asking stanimal, he just modded askthedust's quadruple devi pedal and it has a tp/nd switch

[McSpunckle]

If you buy a 2222N2 it'll already be flipped.

[Here Lies The Fire]

Try asking stanimal, he just modded askthedust's quadruple devi pedal and it has a tp/nd switch

I just did he said he would post some gut shots after he is done with a current pedal that he does this in.
you do have to use a 4pdt switch xD

[zezozeceglutz]

Actually, because the 2N2222A on the left has one leg floating in the breeze, you can do it with a 3PDT.

[McSpunckle]

It'd be neater with a 4P, though.

I'll make a diagram if you'd like one.

-edit-

I made one whether you want it or not. Put the wires where the transistor would normally go, and ignore the extra hole.

The X on the switch can be made with two component leads, just make sure they don't touch. I usually put one through the holes on the lugs, and one on top of the lugs.

[culturejam]

Actually, because the 2N2222A on the left has one leg floating in the breeze, you can do it with a 3PDT.

Actually, since the collector isn't connected at all, you could just use a diode instead. That's exactly what you're getting the way the transistor is used. Any silicon diode with a forward voltage of around 0.7v will work just as good.

[McSpunckle]

^That's true. Unless you're using the oscillation point, and you probably aren't.

Thinking about it, I'm not sure flipping that transistor would really do much of anything...

[stanimal]

^That's true. Unless you're using the oscillation point, and you probably aren't.

Thinking about it, I'm not sure flipping that transistor would really do much of anything...

just makes it noisy as fuck.... or a Never Drive.....

to be honest if you demo one devi, step away, then demo another, you might fall into that "false sense of fuzz security" in thinking that they sound the same.... but when installing a switch to flip between the different circuit designs you really can tell the difference....

it does make a difference, but that's only my opinion....

here's a pic of what i've started doing with my TP/ND flip switch mod... the whole point of this is to use ONE SWITCH to go between circuits and since it's a devi design, that is totally capable this way....



this is only step one... i will update this thread with more pics as i go.... but what i've done differently is mount the emitter and collector on one side of the switch, so i plan to use the middle lugs for my wires going to the circuit board and then jumpering the emitter and collector lugs in a criss-cross pattern to the lugs on the other side... similar to mcspunk's design, only i swapped wires and tranny lugs....

[Jero]

Ho-ly shit this benefits me
thanks guys

[culturejam]

Thinking about it, I'm not sure flipping that transistor would really do much of anything...

I think you're right. Either way, it's just using the PN junction as a diode, and the voltage drop should be the same with either base/emitter and base/collector.

Okay, so let's test this. I'm use a Peak Atlas DCA and a 2n2222a metal can tranny.

• With the leads on base and emitter, I get a reading that the emitter is the cathode and the base is the anode. Forward voltage = 0.82v
• With the leads on base and collector, I get a reading that the collector is the cathode and the base is the anode. Forward voltage = 0.75v

Interesting. So there is a small difference in forward voltage. I tested each configuration 3 times (on two different transistors) and the numbers are consistent.

I just checked a 2N2219, and I get 0.73v for both junctions. Same for 2N5089, except it was 0.8v.

So it must be something specific about the 2N2222 transistor that it has slightly differing Fvd on the different junctions. Odd.

[stanimal]

culturejam i want your brain.....