using the MAX1044 with a 9V wall wart

Started by zjokka, March 17, 2007, 11:24:18 AM

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zjokka

I don't use batteries in my pedals, so use DC jack only. At home, I have some dc jacks wired to batteryclips for emergency.

More to the point This morning I measure my '9V' Boss power supply to be 12V or so without a load.
Now I already wrecked one max1044 chip to find out you cannot feed them more than 10V.

I really would like to build a high voltage booster that would like anything else takes the 9V from the pedal board.
How do I make sure it's safe?

thank
zj

petemoore

  LM317 or voltage regulator does this job well, will hold a constant voltage, when set up to do so, see data sheet, it drops the voltage a little voltage to operate, a 12v to 9v drop would work fine.
  Series diodes from the power circuit +, count the diode drops/measure the voltage drop [a DMM, diodes, and battery demonstrate this] or get a zener to do X voltage drop, of course if the supply voltage moves, the circuit input voltage follows.
Convention creates following, following creates convention.

zjokka

oh thanks pete, solutions with options.
I thought I posted this question before whether the max1044 would work with a wall wart, but the issue here is more the ww in question I believe. The 9V adapter I used came with my Boss ME-50. If I connect it would it drop to 9V because of the load?

or why do they advertise it as 9V then?


stumper1

What's the part number on the adaptor?  The Boss PSA-120 should allready be regulated and put out about 9.75v loaded OR unloaded.  The ACA series adaptor is NOT regulated.  I run a PT-80 with a Maxx1044a charge pump with no problems .
Deric®

zjokka

Quote from: stumper1 on March 17, 2007, 03:54:01 PM
What's the part number on the adaptor?  The Boss PSA-120 should allready be regulated and put out about 9.75v loaded OR unloaded.  The ACA series adaptor is NOT regulated.  I run a PT-80 with a Maxx1044a charge pump with no problems .

It's ACI-220 J which is probably the EU equivalent (AC International - 220V). But don't really want to use that. Bought a multiblock to come home and find it give me 8.86V or something, it's this one:

http://www.stagebeat.co.uk/P/3139/DPS-108

stumper1

Did some quick hunting (Boss's web-site kinda sucks).  It appears as though the ACI series is a higher current (1000ma?) versoin of the ACA (200ma).  I don't believe these are regulated which would be a problem.  The PSA series is regulated (not sure, but I believe the Euro part # is PSA-220).  In the states these are half the price of of the ACI adaptors ;)

I've also had really good luck with the Visual Sound One Spot adaptors.  Not sure if they make a 220 version.

Good luck
Deric®

zjokka

Quote from: stumper1 on March 18, 2007, 03:30:25 PM
Did some quick hunting (Boss's web-site kinda sucks).  It appears as though the ACI series is a higher current (1000ma?) versoin of the ACA (200ma). 

Yeah that's right, 1000mA.
If my other power supply puts out 8.8V it's surely save and regulated?

thanks!
zj