Adding diode to power supply or boost converter to run in parallel or series

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RogueRose

Joined Oct 10, 2014
375
I have a few voltage boost converters that step voltage up to 36v and up to 180 watts each. I can tune the voltage to hundredth's of a volt so there is very fine tune adjustment. I'm wondering if I can use a few of these in parallel and thought if I did that putting a diode in line with the output line (I guess the positive side). So it looks like a 6A diode would work.
Here is the basic unit I have buy mine is a little different:
Gowoops 5PCS 150W DC-DC 10-32V to 12-35V Step Up Boost Converter Module Adjustable Power Voltage

These are the units that are very similar to what I have but mine are rated at 180w instead of 150w, but basifcally the same V-in and V-out numbers
Here are the diodes I've found. I don't know if I need a Schottky, Zener or some other kind for this application.
RECTIFIER DIODE 6 AMP / 600 PIV $.50 each

6A 100V RECTIFIER, GI 751 $.35 each
6 AMP DIODE D6A (10 PACK) $6.75

6 Amp 1000V Axial Diode Rectifiers (Pack of 40) $13.88

T6A100L 6A 6 Amp 1000V 1KV Axial Diode Rectifiers $.26 each

T6A60L 6A60L 6A 6 Amp 600V Axial Diode Rectifiers $.26 each

I also need some rectifier diodes for general purpose use and have not gotten them because IDK if one of the speciality types like the Zener or Schottky or whatever are the better option. Can anyone suggest what I should buy in this specific case and what I should buy to have on hand for general purpose electronics work?
Now when I hooked up one of the units I messed up the voltage and fried a resistor on the back that is labelled R010 and I don't have experience with SMD components but I'm pretty sure that the item is a 2512 which has measurements about as close as any SMD component with maybe 1mm off on the width or length. Some charts show that the resistor of this size is .5w or 1w, or 2w and they all have the same physical measurements, so I have no idea what size resistor I need to buy to replace the unit on the device. Can anyone help figure this out? Some charts list the 2512 resistors as .5 w and others list it up to 2w, so how can I figure this out?

So, is it possible to put these devices in series just as a person might put batteries in series or even even parallel? I'm not sure a diode would be necessary for parallel but I could see how it might be need for series.
 

ebp

Joined Feb 8, 2018
2,332
Just the paralleling question for now:

Paralleling voltage-regulated power supplies without added balancing circuitry is possible but the sharing is rarely what one might wish for. Because the "error amplifiers" in power supplies typically have very high gain at DC, constant voltage supplies generally do not share well in terms of each contributing an equal fraction of the load current. A power supply that regulates at 10.0 volts will often go to its current limit before a paralleled supply that regulates at 9.9 volts will even start to contribute to the load. Sharing can be improved by "ballasting" - adding a small resistance in series with each power supply's output to the common load, but this degrades regulation. Tweaking the output voltages to accomplish equal sharing might help, but often drift with time and temperature (an always-and-forever issue with all analog circuitry) can undo the tweaking after a period of time.

When paralleling power supplies, diodes range from a waste of power to necessary, depending on the specifics of the power supply design.
 
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