LM2596S LM2596-ADJ Constant Voltage / Constant Current Module, Aka HW-155

[LaserSteve]

After spending massive time searching for a schematic for this beast from Amazon / Ebay Etc..
I found it. 

Please see attached.

LM358 monitors a copper trace used as a sense resistor on the bottom of the board. CC demand signal from the LM358 is applied to Pin 4, Feedback, through an LED used as a diode and indicator at the same time.

Estimate is ~14 milli Ohms for R Sense based on various online reviews.

Apologies if there is already a thread on this widget.  My post is to make it easier to find the schematic for the next person.

MPJA Electronics is out of business, sadly.  Skycraft Surplus  has picked up part of MPJA's line.
Off topic: If I'm in Orlando, Fl  and I have a choice of a day at Disney or two hours at Skycraft, I'm going to Skycraft.

I'll add pics and scope shots, later.

[wraper]

None of those cheap modules are based on real LM2596. Most likely it runs at about 60 kHz

[LaserSteve]

[LaserSteve]

A look under the microscope reveals that both the LM358 and LM2596 have some of the worst laser engraving I've ever seen. Yes, Fakes.

I wanted to see where the current sense trace lands. I desoldered one cap and one resistor to follow the trace   It ends up at Pin 6 of the LM358, making it easy to cut the copper sense trace mid span and put in a higher value sense resistor.

Steve

First Picture has component Side CONSTANT CURRENT feedback wiring in Orange. Resistor removed for photo sets on Orange and Violet Pads. Filter Capacitor removed for photo sets in Black Ring.   Low side  copper sensing resistor trace is on back side of board.  The signal goes to Pin 6, Side two input of LM358.

See Attached

Steve