DC 24V 12V to 5V 5A 25W Step Down Converter Module Buck Reduced Voltage Regulator Car Power Converter 24 Volt 12 Volt to 5 Volts Direct Current Converter (1-PCS)

I used this on my classic 68 Mustang 12 volt car for a vintage 6volt Midel A oogah horn

I am using this to run a dedicated power supply to a USB powered, Android Auto unit for my car. Works well so far.

With these DC step down converter modules, the possibilities for custom car electronics projects are endless. This converter module allows you to efficiently reduce the voltage from your car's 12V power supply to a stable 5V, making it perfect for powering a wide range of devices.I used one of these converter modules to connect a Knight Rider scanner light bar using an Arduino that I made for my Can Am SxS to easily connect battery power to the Arduino board. By connecting an Arduino microcontroller to the 5V output, you can power the board from the 12v SxS battery with the LED lights powered directly from the SxS battery.More practical, which I also plan to do, is to use the converter module to power a USB charging station. Simply connect multiple USB ports to the 5V output, and you'll have a convenient way to charge your devices on the go.The compact size of the converter module makes it easy to install in tight spaces, and its high efficiency ensures minimal power loss during operation. Whether you're looking to add custom electronics to your vehicle or a DIY hobbyist searching for a versatile power converter, this step down converter is a great option for numerous electronics projects.

VoC (open circuit voltage) from this buck converter was 5.11V measured from my Fluke DMM. The buck converter is sealed inside a non-serviceable case and thermoplastic butyl packed around the wires that provides IP68 water resistance. I didn't test the output voltage at different loads as I need something close to 5V output to charge the batteries for solar powered cameras. Small fluctuations in voltage is typical when charging via solar panels so stepping down from 20V to 5V +/- 0.1V is acceptable for the installation.The buck converter doesn't have any heat sinks so I would assume if you're planning on drawing 5A maximum current you will need some space for air flow around the converter. I connected the buck converter to my oscilloscope and it showed a peak-to-peak fluctuation of 1.1mV around 5.1 volts. I uploaded a 10 second video to show the DC signal from the converter. The resistance on the ground leads are tied together at 0.6 Ohms and the power leads are inductively coupled.

Pros—This nice, inexpensive compact unit steps down an input DC voltage in the range of (12v to 24v) to an output of 5V (almost - see below). I'm not sure why they label the input voltage as "12v/24v" as if it's a binary choice, but it works well in the full continuous range with a measured efficiency of 84% (input of 12v) and 90% efficiency at 24v input. The input current at 12v was about 2.4A (see pic) when running a 5A output (see pic)Cons - I never got 5V out of it. 4.8v was the max output voltage over the full output current range. Using a programmable load, I tested efficiency and voltage at the rated 5A output for both 12v input and 24v input, but I never achieved 5v (see pics). 4.8 is useful, but it could be a problem for some applications. I left it on for 15 minutes at 12v input and 5A output, and the upper left corner of the unit got to 101°, and I suspect it would have gone higher.NET: This is a nice, compact, inexpensive buck converter; just beware of the output voltage limit, higher current on the input, and temperature issues if they apply to you.