DROK DC-DC4.5-30V to 0.8-30V Constant Voltage and Current Buck Converter 12V to 5V 5A Step-down Voltage Regulator Module Board LED Driver Power Transformer

I have a couple of these guys - different models but they perform flawlessly!! I am using them for theater props to bring down a rechargeable pack to 5v at 4.5 amps. They do not draw much power at all in stndby and run cool even when supplying max amps.

Unit was bench tested upon receipt. Output voltage equaled input voltage. Current and voltage adjustments had no effect.Checked the potentiometers. Current adjustment ok. Voltage adjustment was not. One side was dead short. Resistance of other side would not change.I replaced it with a DROK DK SD15W40V-ADJ (buck only) which worked flawlessly.

This is a well-made module that passed all tests on the bench and worked fine. Constant-voltage (CV), constant-current (CC) mode both work. But you have to know some details of where you will use it.One end of the board has two input terminals, IN+ and IN−. On the other end are two output terminals, OUT+ and OUT−.This board expects to supply your load between OUT+ and OUT−, and for the CC feature, it measures the current in the path between OUT− and IN− (that R010 resistor seen on the solder side appears to be the current-measuring shunt).What that means is if you use this device in a setting where IN− and OUT− are connected by any external path (say, both grounded to the body in a vehicle), this device will not see the amount of current flowing, and the CC feature will be useless. (I am glad I tested on the bench, and the power was coming from a supply that had its own current limit, which saved the day.)DROK's store shows a lot of similar modules, so I opened a question on their forum to ask if any of the other ones will work and do CC in a circuit with common negative. Sadly, their answer was "We are sorry so far there are no similare items can meet the requirement of common ground."Giving four stars because the module is fine for what it is, I can't fault it for having a certain limitation, but the description should have said so.Meanwhile, I used "Ask a Product Question" above, and so far it has only attracted one, wrong answer. After testing and checking with DROK, I know the right answer now, but I'm apparently not allowed to supply the right answer to my question. Could somebody who sees this and is not me please add the right answer to the question, so that isn't forever showing the wrong info?

I got this to use along with an inexpensive 12VDC 10A power supply to limit current in high power LED's. While output constant current is limited to 0.1 - 5.0 amps, it should handle 5-6 10W LED's. After verifying that it works properly, I decided to add a DROK 0.28" DC 0-100V 10A Digital Current Tester Gauge Red Green Bright LED Display to facilitate setting voltage and current. Unless current adjustments are to be made infrequently, I think it's too cumbersome to put a meter in series with the load every time. That is no longer an issue with the DROK display I added. The resulting system works exactly as I'd hoped it would.The PWM capability is a feature that will be of use to me driving LED's. While instructions are sparse, I found that the key to using PWM is the "key" contact point. I soldered a male header to the three holes provided -- GND, PWM, and KEY, from left-to-right, respectively. If KEY is connected to GND, output power is cut. I would presume this may have been intended for use with an on-off switch. If PWM is grounded, however, no effect is seen. But when PWM and KEY are connected, power is cut.I tried using a 2N2222 transistor on one of the Arduino's PWM data pins with an analog write, and after using the "setPwmFrequency" to put the frequency within the necessary range of 100 - 300 Hz. For this I divided the native frequency 31250 of pin 11 by 128 to give a frequency of 244 Hz. Pin 11 was connected through a 1 kOhm resistor to the base of the transistor with PWM and KEY on the collector and emitter, and this seems to work for PWM dimming of the LED's, although I don't have a lot of experience with it yet.So while this system won't handle over about 60 watts, it should be fine for my current intended use. I'll update this review if I encounter negatives in either the buck supply or the DROK meter and display.

BROKEN DID NOT WORK. DO NOT BUY THIS PRODUCT! Did not work no matter what i did I tried turning pots all 1 way nothing. Tried all other way nothing. Tried both directions and nothing the product is just a wqaisted item worthless do not buy this item I do not even have a link to speak to the dealer to maybe get a new working item so sad now I am out my money. Well lesson learned no more electronic parts from this guy. I purchased this item to help me with my powering of elwire signage i made for Alice in Wonderland The movie through the looking glass and now I will be past my deadline over defective item thank you so much.

Does an efficient down conversion that works well in my battery charger application. Easy to set up by cranking the voltage pot to 13.4 and the current limit to just below the max output of the recycled power brick that's driving it. The third pot sets the LED voltage/current indicator threshold. Green when in voltage mode (indicates battery is floating at 13.4), red when hard charging in constant current mode and flickers between green and red when approaching full charge. Always runs cool and made a precision battery charger out of an old 19 volt power brick that would have gone in the trash otherwise.