step up convertor 24VDC to 48VDC recommendations

need a simple DC convertor 24>48V for phantom power duties for a single preamp project, current draw <100mA.
Nothing too snobbish, I'm living for years now with switched supplies without a single problem.
anything you have experience with that works satisfying ?

I have always used AC/DC converters. There's actually not a huge selection of DC/DC. And 100mA is really small. You're almost certainly going to have to go a little bigger and load it to keep it out of hiccup mode.

andre tchmil said:

need a simple DC convertor 24>48V for phantom power duties for a single preamp project, current draw <100mA.
Nothing too snobbish, I'm living for years now with switched supplies without a single problem.
anything you have experience with that works satisfying ?

Click to expand...

For modest current (like phantom power for one mic), I have used a simple variant on cap doublers. These generally operate at mains frequency from a transformer winding. I needed phantom voltage for a unit that already had a switching supply providing the circuits power. I piggy backed a tripler on the existing full unregulated voltage square wave. Since this switcher was running at something like 100kHz I was able to deliver adequate current from tiny SMD caps.

They sell dedicated DC to DC regulator chips based on this technology called "charge pumps", one benefit of charge pumps is that there is no magnetic field like typical DC to DC inductor based switchers.

You could roll your own using something like a 555 timer to make the square wave than stacking up a cap doubler/tripler.

Or not...

JR 

https://www.electronics-lab.com/project/24v-48v-1-5a-step-dc-dc-converter-using-lm2588/

all good info ; keep it coming.

Why don't you just stack a small 24v PSU on top of the original 24v supply ?  24 +24 =48

Rob Flinn said:

Why don't you just stack a small 24v PSU on top of the original 24v supply ?  24 +24 =48

Click to expand...

space issues , really.

I swear I've seen a very small DC convertor a few years ago. Lambda, TDK ?
was only the size of a TL072 or so.

andre tchmil said:

space issues , really.
.....

Click to expand...

Is this one small enough (for lower output currents the heatsink can be removed):
https://www.ebay.com/itm/DC-DC-3-7-35V-to-5V-50V-12V-24V-36V-Converter-Step-Up-50W-6A-Power-Supply-Module/173928779601?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

Not all SMPS are created equal. The good ones are very carefully designed and constructed. Also, the possible output voltages depend on the input voltage. Meaning you might not be able to get 48V from 24V.

Several times i’ve used the small dc-dc converters found on ebay.

They work well but i never used them for powering audio circuits, just pilot lights or relays.

If current is low you can use a diode-cap doubler or a charge pumps IC.