Looking for a high wattage 5V input capable boost controller

[Mosaic]

I can't seem to find a decent boost controller (EBAY) that takes a 5V input .
I am looking for perhaps 12VDC to 16V with up to 15A capability on the output side.

Paralleling cheaper 3A boost controllers looks like a pain to make them current share properly as there is no guarantee that drift won't destabilize the whole thing after it heats up some.

Maybe adding a sampling uC with thermistors on each boost IC might be the way to regulate any drift with some filtered PWM feedback from the uC adjusting the feedback loop on the boost ICs.


Advice anyone?

 

[kinarfi]

eBay,
1200W 20A DC Converter Boost Car Step-up Power Supply Module 8-60V to 12-83V
or
900W DC-DC Boost Module 8-60V OUT 10-120V Step-up Converter Power Supply F1B8
I have bought both and I like the meter on the 900W, the 1200W may prove closer to what you asked for, the 900W limits it's input current to 15, output will be proportionally lower compared to boost.
Jeff

 

[Mosaic]

Need something that accepts 5V input.

 

[kinarfi]

Need something that accepts 5V input.

I'll test mine, see what they do, what's the minimum output current you can get by with?
16v and 15 amp =5v and 48A, but I'm sure you know all this, I suspect you using a computer power supply ?????
Jeff

 

[Mosaic]

Well, If you can let me know what your units produce I can see if it's doable.
I have 5VDC @ 50A available.

 

[schmitt trigger]

There were some old Intersil and Unitrode app notes on paralleling converters. The key is to sense the output current and adjust the feedback accordingly.

Paralleling a couple is no major problem if one of the converters operates as a master and the other as a slave.

One important thing: Loop stability. Stability requirements become more difficult as more converters are paralleled. There are local and global feedback loops competing for control.

You can always avoid that complexity, if the Ebay converters have and adjustment pot. Adjust the voltage of all the converters to be as close as humanely possible. Then add a low value (100 milliohm or less) ballasting resistor on the output of each converter.
Regulation will degrade somewhat, but it is a doable project.

 

[Mosaic]

I need one feedback loop to rule them all...

 

[kinarfi]

I was playing video games(simulating with Spice) and thought about your problem, I don't know how this will work in the real world, but it might if groomed out further, who knows? play with it and see what you can do.
I tried my 1200 W module and it did nothing, didn't try the 900 W.

 

[Colin]

What is the voltage-drop when the 5v is supplying 50A ?

 

[kinarfi]

Mosaic,
I assembled this circuit planning to use it to boost 12V to 30V to drived a COB LED at my work bench, I made a mistake and turned it up to 35V and ruined the COB LED. I turned the output down to using the duty cycle adjustment and then turn the output down further using the feedback from Vout and stopped at about 17V. I then turned the input down to 5 V and the output held constant down to ≈ 4.5V. I didn't have much load (100Ω), I didn't work with it much after that, end of the day.

 

[kinarfi]

I did some more testing of the circuit in post #10
Vin=5.04
Vout=12.17@840ma
Vb=.528
Rl was 12Ω + amp meter and jumper leads