DROK Buck Boost Converter, DC-DC Buck Boost Converter Voltage Step Up Down Regulator CC CV 5-30V to 0.5-30V Adjustable Power Supply Transformer Module

I used this in an inverter that had a variable speed fan. I upgraded the fan and I wanted to run at full speed no matter what the voltage. This module supplies 12 volts to the output after the input is at 5 volts or higher. The output is rock steady at 12 volts. Perfect for a flicking light condition. Drok makes great products.

Seems good for the cost - I'm using a couple of these as "float chargers" for sealed lead acid batteries (ham radio portable gear). They do a nice job of taking "whatever" input -- I've tried as low as 5V from a USB phone charger or as high as 22V from an unregulated solar panel and it does an excellent job of charging at 1.5A (current limited) up until it trails off as it peaks at 13.9V (voltage setpoint) very nicely charging my batteries without hurting anything. I had to use trial and error to adjust the voltage and current...the shorter POT with a "+" head is the current, start by tweaking to find the min/max then center it between those positions. Then hook up a volt meter and dial the tall POT (slotted screw head) until you find your desired voltage. Finally put a high current ammeter on the output (shorting it out) and dial the shorter POT until you get the max current you want it to pass. Unhook that and switch back to a volt meter verify the output is still good and you're done. Note that under high load when it hits the max current the output voltage will sag down, that is normal but something you may need to plan for...e.g. if your cooling fan needs 10V to start and you try to charge a battery that drags output down to 9V it may not run your fan. I would suggest planning to build a cooling fan into whatever you use this in, even at 1.5A it gets rather hot for my like without any cooling, though even minimal air flow does wonders (small PC fan works nicely). As others said, the heat sink is barely attached, one of the two I got the heatsink was already broken off so I had to use some thermal epoxy (like CPU heat sink paste, but 2-part epoxy glue that hardens) to re-attach it. All things considered, this seems a very good deal for low-current DIY projects.

A good DC-DC converter and is so far working for my purposes. No user manual though. It's a simple product, but I'd really have appreciated a simple instruction manual and/or diagram; it'd just make me (and I'm sure a lot of entry-level users) feel better. EDIT: I was able to obtain a brief un-proofed manual for this, explaining the functions of the two potentiometers ('screws') on the board, and the LED indicators. I've uploaded it for everyone here: http://rnaservices.net/public/manuals/solar/DIY/DATASHEET_200234_boostbuck_manual.pdf

Running this at 2.2A output @ 25V and the bottom of the board is at 175F. Inductor is at 160F. Too hot for my tastes! It would be great for lower output use (below 1.5A).

Stopped working and would not output more than 43mV after about 1 hour of light use (always less than 400mA, usually less than 250mA). Worked great and held a steady voltage across multiple input voltages, until it stopped working. Look elsewhere if you need ANY long term reliability.

Work well and even hot they keep on going.. Nice output low noise and well made. Crazy good price!

Amazing little circuit. Use in my travel trailer for the lights (most are LED). Out put is a constant 12 VDC even if the battery voltage falls to 10 VDC up to 14 VDC. I tested it and ran the input voltage from 6 volts to 30 volts and the output voltage was a constant 12 volts with a 0.5 amp load.

I did a bunch of measurements on this converter. I tested it from 13.6V input and loads up to 3A. Vout is continuously variable from 0.5 to at least 24V. The negative input and negative output can be connected together, but it will affect the current limit behavior. During an abuse test, I managed to blow the input fuse, which is 5A and solder in. Output regulations is very good, less than 1% from zero to 3A load. Output ripple is 25 mV rms up to 20 MHz plus 120 MHz ringdowns about 400 mV p-p. Input ripple is a 200 kHz triangle wave and is up to 50 mV rms at full load, with 120 MHz ringdowns 1V p-p. I recommend a common-mode choke on the input and output to suppress the 200 kHz harmonics and VHF ripple. Overall, very good noise performance for a low-cost converter module. At 3A continuous (36W), all components get quite hot. Sitting open on the bench at room temp = 25C, I measured the following temperatures: Heatsink 73C, inductor 77C, and the first output capacitor 82C. That final measurement is worrisome from a reliability standpoint; that capacitor will fail prematurely. I can't recommend running this device at full output very long without forced ventilation. At elevated ambient temperature, it won't last long...

Perfect device with lithium battery portable power supply for electronics field kit. Can be used to output various voltages for prototype circuits; maintains excellent regulation. Also able to be employed with solar panels for safely charging the lithium cells as the constant-current mode can be set to shut down charging when cells are full to prevent overcharging. Easy to set up using multimeter.

Used it to regulate LED lighting in a camper. When on shore power voltage was 13.8 which will eventually cause LED strips rated for 12 VDC to fail. Used this to regulate to 11.99 VDC.

I have tested it the hard ways and it was very stable on many different input voltage and changing output currents. The output voltage is very stable even if you change the load. I was amaze !

Arrived quickly, and works nicely.

Works as expected.