Review on Adjustable Converter 1 25 36V Efficiency Regulator by John Kennedy

I received them today. Considering that the seller offers refunds for all non-working devices, I immediately checked them all to see if they were DOA. There was nobody! I will update if any of them fail. In general, these are pretty good devices based on the XLSEMI XL4015 chip. The circuit seems pretty straight forward from the datasheet application notes, except that the output capacitor is 220uF instead of 330uF as suggested in the datasheet. All boards appear clean, undamaged and well soldered. When tested, their output stabilization, dependent on load and input voltage, seemed excellent. The output voltage remained constant at 5.0 V with an input voltage of 9-14 V and an output current of 0-0.5 A. At 0.5 A, only the ring choke heated up a bit. All other components stayed cool after a few minutes even without installing the included heatsink. The low current draw isn't great, but that's to be expected. But even at 9V input, 5V @ 51mA output, I measured an efficiency of just under 70%, which saves about 10mA current draw compared to a linear regulator. A simple modification to slightly improve the low current performance would be to remove the power LED from the board. At 5V I measured the current consumption of the LED at 0.65mA. The only disadvantage? I did not receive the frames pictured. This is a small complaint as I probably don't intend to use them but it would be nice to get everything as shown in the picture. --- In case it helps anyone, here is a summary of the notes I took while testing all four modules. This isn't an extensive series of tests as I mainly just wanted to make sure they would work in my low current application, but maybe someone will find them useful. Results: Output voltage with no load: 5.00V, 5.00V, 5.00V, 5.00V Output voltage with 10 ohm load: 4.99V, 5.00V, 5.00V, 5.00 input current no load (@13.6V): 5.0mA, 4.9mA, 4.8mA, 4.6mA 10Ω load input current (@13.6V): 210mA, 220mA, 210mA, 210 mA. in: current consumption 41.6 mA, efficiency 69.6% LED current consumption: 0.65 mA (3.32 V over 5.1 kΩ resistance)