XL6009 based DC/DC Converter for sensitive audio voltages like e.g. phantom power?

[ccaudle]

Synchronise all switchers

You obviously don't get a chance to synchronize the offline switcher. Do you have some experience with recent generation products to have a guess about how much filtering is needed to avoid beating with downstream switchers?

 

[alphasnk]

XLR connectors are nice, but that loses the entire reason for using USB-C. It has nothing to do with liking the connector, and everything to do with taking advantage of the economies of scale driven by laptop and phone manufacturers to get a high performance power supply at a low price and easily available all around the world. And you can't get those kind of power supplies with a mini-XLR connector installed. So if you want to build your own small GaN offline switcher you can put whatever connector you want on it, but if you want an inexpensive commercially available one you get USB-C.

I understand totally, i hadn't looked at how usb-c worked yet. I did that yesterday thanks to @thor.zmt, after i posted here. I will use that today in my tube mic PSU. I wanted to come back and thank Thor for his recent messages (the superb recent thread @Emmathom created was a true forum convo haha)

Thank you as well

 

[alphasnk]

I've ordered a JSI Progue synth (it's a moog rogue / prodigy fusion) it uses a Traco DC/DC thingie i had not seen yet.

If you have an opinion on that kind of things:
https://www.reichelt.com/fr/fr/shop/produit/convertisseur_cc_cc_serie_tmr-3_9-18_-15_v_c_c_-122814

 

[thor.zmt]

What did you guys think about that kind of dc/dc : https://www.tubetown.net/ttstore/en/tt-vpump-voltage-converter.html

Antique that belongs into the museum?

And i'd also be curious if you have an opinion about: usb-c vs tiny xlr 4 poles ?

USB - C & HDMI, super commodity, GX-12 otherwise for multipole.

Also, USB-C allows power selection of 5/9/12/15V @ up to 3A and 20V/5A for bigger laptop's and now even 48V/5A. Only the 240W 48V/5A sunset is currently not supported with extrnice diy friendly off the shelf hardware.

I buy the more affordable 100W bricks for around 50 USD, GaN power train, tested for agency compliance. It will not electrocute you, your customers or worse the Mega Star Singer using the gear.

I just cannot make myself deal with other stuff for cases where 100W input power suffice.

Thor

 

[thor.zmt]

You obviously don't get a chance to synchronize the offline switcher.

No, but that's not really an issue. You are using it only as raw DC. Switching frequencies are nowadays 67kHz/132kHz and up. I need to tear down one of these GaN thingies to see where they switch.

I read 300kHz...1MHz (which is why they are so small for huge power ratings).

"Industry standard" designs tend to aim for 100mV PP or less at the switching frequency at rated power. Cheap garbage will have more noise.

The bigger issue is "green mode" operation if there is insufficient load. The better strategies use cycle skipping, but the easiest and cheapest is frequency modulation. So switching frequency drops from (say) 67kHz to the audible range.

Do you have some experience with recent generation products to have a guess about how much filtering is needed to avoid beating with downstream switchers?

Keep enough separation. Easy.

If all downstream switchers sync at an integer multiple of 750kHz, your off mains switcher is 300kHz, what is the first beat frequency?

Keeping secondary switcher frequency high, the chance to get the off mains switcher to have switching noise within 20kHz or less of the main switcher is low.

Thor

 

[alphasnk]

Also, USB-C allows power selection of 5/9/12/15V @ up to 3A and 20V/5A for bigger laptop's and now even 48V/5A. Only the 240W 48V/5A sunset is currently not supported with extrnice diy friendly off the shelf hardware.

Yes that's what i've seen. I was surprised that it needed a 'handshake' with a trigger. I will try that for the first time today

 

[thor.zmt]

Yes that's what i've seen. I was surprised that it needed a 'handshake' with a trigger. I will try that for the first time today

It is a protocol extension on the original USB 5V/500mA standard and the later USB 3 5V/0.9A. Now we are at 48V/5A which would fry many an old USB peripheral very crispy.

On top, USB-C is dual role. The same socket can receive power or provide power.

To avoid damage to downstream equipment by sending the wrong voltage, USB-C requires an explicit handshake to turn on power at all. The handshake defines roles (though roles can switch on the fly), voltages etc.

Recent standards have variable Voltage on the handshake.

You use this for "flash charging" where the battery powered device completely bypasses the internal charging circuit and connects the battery directly to the external source.

The controller requests the voltage in 50mV increments (or something like that) that causes maximum permissible charge current.

So a Laptop might charge a 14.8V/3,500mAh battery pack at 5A or more on the external USB-C brick with 95%+ efficiency.

Seeing that most monitors, LED lights kitchen appliances etc. do fine with 240W max. I think USB-C will soon be a normal wall socket just like AC.

I'm planning on an inverterless Solar system with 48V DC using nickel iron cells (1.2V, 500Ah, 25 years guaranteed lifespan, 24kWh storage) with USB-C the main power socket for the next house (will be 100% off grid).

Thor

 

[alphasnk]

In France they voted a law in late december 2024, so that phone manufacturers must provide a usb-c connector.. No and it's cool because it was such a pain to have to deal with different sizes of ********.. I used a usb-c hub that i use for my laptop, it has a port for charging and a hdmi output, we used that to display a nintendo switch on a tv, without having the dock for it, and it charged the console.. It's really convenient.