Voltage converter question.

[Focalized]

I want to built a couple pedals that use a 9v to 12v converter built into the layout.

What would happen if I plugged a 12v supply into such a thing?

Or is such a design now limited to a 9v supply?

[slacker]

Depends what converter you're using, some will die, some will give you more than 12 Volts out, some will give you 12 Volts out.

[Focalized]

Lets say it's a MAX1044.

[Seljer]

The MAX1044 likes letting its magic blue scope escape if the supply voltage gets too high. In the data sheet under "Absolute maximum ratings":
Supply Voltage (V+ to GND, or GND to V OUT)...10.5V


Go look up at the LT1054 or TC1044

[italianguy63]

Chip   Max voltage   Freq max (Khz)
LT1054   15   40
TC962   18   24
MAX1044   10   30
TC1044S   13   45
ICL7660   10   10
ICL7660S   13   35
ICL7660A   13   10
TC7660H   10   120


LT1054, TC1044S, or ICL7660S.

The LT1054 is best for higher voltage.  The TC962 has a lower frequency, and in my experience has some noise..

MC

[R.G.]

Lets say it's a MAX1044.

You need to say more than that. Depending on *exactly* what the converter is, how it works, and what the rest of the circuit is, you might get
(1) Works fine, hardly noticed
(2) Well, at least it didn't die.
or
(3) Boy, these things really smell bad when they burn.

The 1044 will die. Some of the other charge pumps can stand voltages much higher, up to 18-20V. But if you're using a charge pump converter, it's trying to double the voltage, then you're regulating to 12V if what I intuit from your post is right. If the charge pump can take it, can your capacitors? And then can your second regulator at the circuit's fulll current? Or will the regulator thermally limit? how much current is this thing putting out, again?

[Focalized]

Actually I completely confused myself. Maybe not, maybe more after someone responds again.

Basically I was looking at these two layouts.

http://tagboardeffects.blogspot.com/2014/06/mutron-phasor-ii.html
http://tagboardeffects.blogspot.com/2014/06/mutron-iii.html

They're using a inverter I think. With a 9v and -9v connection on the board. I'm not familiar with what's going on. Is there voltage increase here? I figure this is how to get 18v actually?
I'm reading things around about it as I type.

The little board uses a ICL7660S. Someone in the messages over there said they used MAX1044 which I have some of. Are they interchangeable in the layouts shown? That is my main question now I think as I thought to try the build with what IC I had.

My original question is not important until I know what's actually going on in those FX.

[Seljer]

All these ICs are charge pumps. The work by they work by filling up a capacitor to your input voltage, then while it's charged up reconnecting the capacitor into the circuit in a different position by using a few transistors and diodes. If you remove it from the circuit filled up to 9v then reconnect it in upside down you get a negative voltage. If you reconnect it back in with the bottom leg connected to your supply you get a voltage doubler. There are whole lot of applications drawn in all these chip's datasheets.

In all the cases, the supply voltage rating has to be observed because the control and oscillator circuitry within the IC and the transistors that switch around the position of the capacitor can only handle so much. The higher output voltage when using at a doubler is irrelevant because there there are the two diodes there that prevent it from flowing back into the chip.

[italianguy63]

The pinout on the LT1054 is different from the "norm."  The connection for the frequency boost option is different from the others.
Because of this, I personally use the TC1044S.  I have had better luck with the TC1044SEPA than the TC1044SCPA; I can't explain why, but I have had quarky problems in my particular application with the "C" designation.  I have never figured out the "why."  And, the supposed only difference is the temperature designation.  (Sorry, off track rambling.)

The ICL7660S is also a fine option if you already have one.

The MAX1044 will work, but they have durability problems.  They are very fragile as it goes to over-voltage or reverse-voltage issues.  Most folks avoid them now.

MC

[Focalized]

Well I guess I'll see. Using a 1044. I don't see any ICL7660 sold at any of the guitar specific stores. The 1044s I have were from smallbear so I trust they are proper quality at least.