18V mod with LED. Could someone please dubble check

[darkcyde]

Im not 100% about this. could someone check behind me plz.
Its suppose to be parallel(both 9Vs as 9v) and series (Both as 18v)

Thanks

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[ashcatlt]

Nope. S/P on a DPDT is an extremely common thing, and exists in a number of different forms both here and elsewhere on the web. What you've got there isn't any of them.

I've got serious questions about having two batteries in parallel. It seems like they will be too busy trying to charge each other to do much good for the rest of the circuit. We've discussed it before, but I can't remember exactly where.

That battery on the right side can't possibly do anything with a cap in series. Caps block DC.

[darkcyde]

I wasnt sure, Im for sh*t when it comes to switches for some reason. (Might be the adhd and dyslexia) LOL

Could you give me a point at one of the better discussions? I tried search fukshun and get could not connect to server.
Thanks

Mike

[ashcatlt]

Pick One

The left hand battery, the led and its resistor will be one pickup. The other battery is the other. IDK what that other R is for. If you really want it in series with the LH battery, then put it there before the switch. Still not sure what that cap is about. If you can explain why you think you need it we can figure out where it goes.

Anybody else want to weigh in on the advisability of this parallel battery thing?

[darkcyde]

First, thanks for the link. That was just what I needed

the resistor and cap was something I found on another forum about killing the pop between switching from 9v to 18v. I assume they were referring to an electrolytic cap. The other resistor is what I came up with after doing the math to figure out what sized resistor I needed to put after a 9v for doing an led to indicate the guitar being on or off. The switch ignorance really does stem from transposing crap in my head. I really suck at switches. I see now looking at it again, that its not correct.


On the parallel battery thing, I was under the impression that this works providing there is a parasitic draw on it. (i.e. the op amp) But with many things in life. Im often proven wrong.

[ashcatlt]

So, first of all the way you've got it now, the LED is always on (there's your "parasitic load" ). This switch does know if the guitar is on or off. All it knows is whether you want 9 or 18V. You can worry about these two components when you get to your bypass wiring. I suspect that you're going to have to pick an R that is safe for the LED at 18V and hope that it's still reasonably bright at 9V, but like I said we're kicking that can down the road till we get this S/P thing sorted...

I kind of figured that the cap and its R were intended to reduce the pop. They are going to be wired as a textbook RC lowpass as a separate module after this S/P switch. I am not completely sure on those values, but we're kicking another can...

So now it's pretty simple. All that's left two batteries and a switch. You literally just have to plug the batteries into any of those S/P schemes I linked.

Then put the 3.3K in series with the + output from the switch and the cap from the other end of the R to the - output.

Then come back and we'll talk about bypass.