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DIY Stompboxes => Building your own stompbox => Topic started by: Chico on March 15, 2004, 12:44:15 PM

Title: MAX1044 question
Post by: Chico on March 15, 2004, 12:44:15 PM
Anyone use these?

I just built a univibe style pedal.  For power, I used a MAX1044 to convert 9vdc battery to (approximately double the volts) using documents provided by RG.  Basically, instead of a switch between pins 1 and 8, I tied them together, otherwise, it is identical to the circuit at RGs site.  I used 2 shotky diodes and I used two identical 10uf electrolytic caps to get about 17 volts out.

I took the output into a 7815 voltage regulator and strapped a 10uf between the 15 volt out and ground.

I put this on its own circuit board.  Then, where the power connects to my effect board, and several places along the V+ trace, I placed 0.1uf caps to ground.

I thought this would make sure my power was clean.

When I look at the voltage out on my scope, I get a solid 15 volts out, but I also see a periodic wiggle on the supply line.

When I replaced the 1044 and 9v battery with my homemade bench supply, I do not see the same wiggle.


Any suggestions for using this chip to get a clean supply output?

Thanks in advance.
Title: MAX1044 question
Post by: claydavis on March 15, 2004, 12:59:03 PM
it may help to swap a 100uF for that 10uF across the regulator.