MAX1044 question.

digi2t · September 27, 2011, 10:55:11 AM

Hi all,

I have an older 18v Dunlop 535Q model wah, which requires two 9v batteries. I was wondering if a MAX1044, set up as a doubler, would be enough to run it. I know the adapter they sell for it puts out 150mA, but that's over-rated to some extent for sure, to extend the life span of the adapter.

I don't know how much current this pedal draws, so I'm not sure if it will surpass the capacity of the chip. I'm just wondering out loud if anyone here has tried this, or has any theory. I'd love to get rid of the batteries, while being able to slip it into my existing 9v daisy chain power supply setup.

Cheers,
Dino

Govmnt_Lacky · September 27, 2011, 11:05:04 AM

You could always try a TC1044 or an LT1054. I believe both of those (I know the LT for sure) will handle up to 100mA draw.

digi2t · September 27, 2011, 11:22:46 AM

Quote from: Govmnt_Lacky on September 27, 2011, 11:05:04 AM
You could always try a TC1044 or an LT1054. I believe both of those (I know the LT for sure) will handle up to 100mA draw.

Thanks Lacky. They both look a bit more robust for doubling than the MAX1044. I'll look into it.

Govmnt_Lacky · September 27, 2011, 11:29:01 AM

No problem

I am currently using the LT1054 in both of my M117 flanger builds and that circuit pulls around 80-90mA (according to my bench PS) and I have had no problems.

I am using madbean's road rage board for my voltage doubler if that helps! Its a great design... many thanks to the Bean!

digi2t · September 27, 2011, 12:15:20 PM

Excellent idea. Ordering now. Will I need to use a regulator? Don't believe so... I'm taking 18v direct, right?

Govmnt_Lacky · September 27, 2011, 01:31:55 PM

Quote from: digi2t on September 27, 2011, 12:15:20 PM
Excellent idea. Ordering now. Will I need to use a regulator? Don't believe so... I'm taking 18v direct, right?

Keep in mind that ANY voltage doubler will not give you 18VDC at the output. You will be looking at ~17VDC plus or minus a few tenths of a volt with a 9VDC input to the charge pump circuit.

.Mike · September 27, 2011, 02:33:18 PM

Quote from: Govmnt_Lacky on September 27, 2011, 11:05:04 AM
You could always try a TC1044 or an LT1054. I believe both of those (I know the LT for sure) will handle up to 100mA draw.

The TC is identical to the MAX except that it is rated for 12V supply. Otherwise, they are the same.

Digi2t, you might want to check out the ICL7660S. It can source more current than the 1044, but still has the boost pin.

Mike

Govmnt_Lacky · September 27, 2011, 02:41:29 PM

Quote from: .Mike on September 27, 2011, 02:33:18 PM
Digi2t, you might want to check out the ICL7660S. It can source more current than the 1044, but still has the boost pin.

Another viable solution!

digi2t · September 27, 2011, 04:48:21 PM

Thanks Mike! Damn, no more boards left at Madbean! Guess I'll just vero it

. I already ordered some LT1054's, but I think I'll get some ICL7660S' as well and tinker.

Edit: Just ordered some ICL7660S', they're pretty cheap compared to the 1044's or the 1054's. I think I'll socket them when the time comes, and run some tests

Thanks a bunch guys! Y'all have a great day now!

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MAX1044 question.