DUBEUYEW LM2596 DC-DC Buck Converter, Adjustable Step Down Voltage Regulator 3-40V to 1.5-35V High Efficiency Power Supply Volt Reducer Transformer Module(4PCS)

Using this as a DC-DC convertor to replace small short lived batteries in some christmas lights. I'm inputting from a large 12v 9ah rechargeable alarm battery and stepping down to 4.5v to replace AAA batteries that only lasted a couple of hours. Mounting holes on the board are a nice touch and the solder pads are a good size. I have just soldered straight to the pads but they are of a good pitch, you could put upstand posts and wirewrap them if you needed to.

These items work fine for undemanding applications like reducing the voltage from 24 volts to 12 volts for running a fan. Like all the other boards of this type on offer they are not actually the real thing. The main chip is a sort of clone and only runs at 50kHz switching frequency rather than 150kHz in a genuine 7569 chip. It is also struggles to to deliver 3amps, getting very hot in the process. That said, if you know what you are buying and the application is simple then they are superb value for money.

Easy to set up,with clear connections

One doesn't adjust as it should but not worth sending back for how cheap they are to buy. Other three work perfectly.