30-35 v and 5ma from a 9v battery

Post by **pamaz** » 02 Nov 2011, 08:34

Hello all.
I need to get some 5 ma and 32-35 V supply . That supply has to be reliable and obviously free from noise in the audio spectrum.
I've seen the rg keen max1044 application to get the 30 something volts.
I've seen the paralleling trick in the 1044 app notes to raise the current capability.
But still I'm wondering if it's enough to put a proper zener string ( something like 9v zener and two series 1n4007) in front at the 1044 to be safe enough regarding esd and voltage overshooting at the input.
Any experience to share regarding such a supply?

Thanks all of you.

Paolo

Post by **pamaz** » 03 Nov 2011, 07:04

hi there. the title could be misleading. I mean 9v dc power supply, not necessarily from a battery. Let's say that i need to raise the power from a standard voltage supply.

DrNomis · Post by **DrNomis** » 03 Nov 2011, 08:51

You could try making a voltage multiplier using a CD4049 IC, a couple of 33k resistors, a 330pF ceramic cap, 5X 1N4007 diodes, and 5X 10uF/50V capacitors, this will generate up to 42V from a 9V battery or plugpack, PAIA sell a Tube preamp kit that uses this circuit, here's a link to the website, download the schematic for the Stack In A Box Tube Preamp and look at how the voltage multiplier is wired up:

http://www.paia.com/proddetail.asp?prod=9210K