3 volts becomes 48?

[ManFromGlass]

Assuming the laws of physics have not been broken -
how can a battery powered Zoom mixer that takes 2 AA batteries provide 48 volts of phantom power for not just 1 but 2 mics?
A not too technical explanation would be appreciated as I dropped all subjects but music in school.

[Hugh Robjohns]

It's magic elves....

Alternatively, you could use 3VDC to power a high frequency sine wave oscillator.

Then you could pass that high frequency AC signal into a step-up transformer to give around 70 Volts AC.

Then you could rectify and smooth that AC voltage to provide 48VDC.

This approach would not be very efficient, and there are various other techniques which are more efficient, under the umbrella term of DC-DC conversion. But it gives a simplified idea of the underpinning concept.

No laws of physics are broken. Power out is less than power in.

[Wonks]

Or more likely a number of charge pump circuits. But there are many ways it could be done.

[James Perrett]

Possibly something similar to the circuits in figures 4 and 5 of

https://eu.mouser.com/datasheet/2/256/M ... -93203.pdf

I've used these chips to generate 48V very efficiently in the past.

[ef37a]

Yes, DC-DC converters. These devices are now very 'mature' and reliable.
A few months ago I used one to produce + and - 15V from a 12V wall rat to power two Spark Fun balanced output modules. Got the converters from RS and I still have another version that take just 5V to produce twin 15V rails. Not deployed that so far.

The Blackstar HT pedals I worked on use a charge pump 8pin DIL chip to produce 300V* from about 20V. The circuit, which used a power MOSFET is extremely reliable. The only fault I found was when the 1meg feedback R went O/C and the output voltage went ape***t to around 450V+. The 10uF 350V cap did not like this and drew a hefty leakage current and the result was that the line lump supply blew its internal heat fuse. Despite all this carnage, once the resistor was replaced (with a 0.5W MF!) all was back to normal.

I hasten to add, this was VERY early on in the pedal's history and the resistor quickly uprated in production. The original AC-AC power supply is now a 22V DC jobby and this failure mode no longer happens.

I actually modded a scrap board with a 1meg trimmer R and found I could get a very clean, well regulated 48V from it.

*N.B! You will get a shock if you mess with that power PCB! Not likely to kill you as you will drop it PDQ but it bloody hurts I can tell thee!

Dave.

[ManFromGlass]

ahh, ok!
So it is magic elves.

[Sam Spoons]

Yes, the elves convert the 3VDC into MBS and then, after processing, the MBS is converted back into 48VDC. MBS is an essential component of all electronic devices, that's why if it escapes the device stops working.

* Magic Blue Smoke

[Folderol]

Yes, the elves convert the 3VDC into MBS and then, after processing, the MBS is converted back into 48VDC. MBS is an essential component of all electronic devices, that's why if it escapes the device stops working.

* Magic Blue Smoke

Oh come on! Everyone knows that's nonsense.
It's really trained microbes on a series of tiny ladders throwing spare electrons up to each other. The ones at the bottom have the hardest job - they have to catch them out of a moving stream.

[ManFromGlass]

So is one supposed to inhale this MBS?
Asking for a friend

[Exalted Wombat]

This article (although from a reputable source) seems to use the term 'power' rather loosely!

https://uk.rs-online.com/web/generalDis ... s-overview

[ManFromGlass]

very interesting.
Thanks!