I needed a new small power supply for my electronics project table. I was checking several options for a lab power supplies, but when I saw DC-DC Step Down Power Supply Adjustable Module With LCD Display With Housing Case I decided that I could use it to build easily the power supply I need. In this case I wanted adjustable voltage and also wanted current meter (I did not need current limiting).
DC-DC Step Down Power Supply Adjustable Module With LCD Display With Housing Case is an adjustable DC-DC step down power supply module with LCD display and housing. The price was pretty cheap (this one costs 5.34 Euros / $ 5.99 , there is also cheaper version without case). The module promises to give out 0V~16.5V (Continuously adjustable) voltage at up to 2A continuous current (peak current 3A). The input voltage is said to be 5~23V. The documentation says that best voltage is 20V.
1 x DC-DC step-down power suppl module
1 x Transparent shell
The parts came packaged to a sealed plastic bag.
Parts taken out of bag:
Removing the protective layers from laser cut plastic parts:
Main module size (the circuit board) is 50mm x 30mm x 12mm(LxWxH).
In my testing I powered it with 12V DC so I got around 0-10V voltage range.
Here is picture of my module in use. I powered the module from 12V DC power. It worked well and was able to give out voltages from 0V to slightly over 10V.
The buttons worked for for adjusting the output voltage. The voltage meter showed the output voltage and the current meter showed the current going to output. The voltage setting is stored to internal memory so that setting will stay the same when you power down the module and power it up again later. Because the power supply is based on switch-mode technology, there is some switch mode noise on the output (around 20-30 mV of noise at around 400 kHz when output was set to 3.3V).
The were some downsides on the module. For example the meters were not very accurate. The voltage meter showed around 3% lower reading than my two multi-meters. Current meter also showed 2% less than real current (verified with two multi-meters). Also the case had issue – if you tighten the screws all the way, it causes that the buttons are in pressed down state all the time.
The module promises 2A continuous current and 3A for short time. There is no adjustable current limiting. The short circuit current to multi-meter when I did test was around 5A (short test did not damage the module). I also did accidental test by wiring the input power wrong way – the module was not damaged by this mistake.
I would say that the DC-DC Step Down Power Supply Adjustable Module With LCD Display With Housing Case was well worth of the price. If you don’t need the case, there is a cheaper version without case available.