DGZZI2PCS 12 V to 3.3 V / 5 V / 12 V DC-DC Voltage Converter Multi-Output Step-Down Power Supply Module for Arduino

Dual AMS1117 chips and quiescent (standby) draw of 15ma @ 12.0v. Look up the AMS1117 to see specs. Basically, 15v max input, 800ma per regulator MAX, better figure something less than that to be safe.Vin is passed through. The description of holes I believe is actually the pin spacing for a breadboard, my guess. Switch is a toggle on/off and remembers last setting when power cycled. Do plan on using it in current application, as at the 15v max is on the edge for a automotive regulator and the unloaded standby at 15v is close to 20ma (to high, other regulators with higher specs have unloaded standbys of <1ma but they also have poor regulation, from what I've tried so far). My application is a Arduino project.

Both of them arrived with bad 5v regulators. 12v and 3.3v are fine but the 5v pins are at 9v for one, 11v for the other.

They work very well but be careful in hooking the wires up, one ROW is for return and the other ROW is for output. I wish they had short-protection protection because I mis-wired one and it failed. My Bad! Pay attention and is a very reliable unit.

Three Points:1) "Two pin holes are specially designed, which can be directly fixed on the hole-board for expansion experiment;"There are NO holes on the board for any purpose including attachment2) Are grounds are tied together (common) including power source3) The switch ONLY cuts power to the board components. Power remains on 3rd position at ALL times. You need to make provisions for an external switch for the power source.

The 3.3v output pins are putting out a full 12v on one of the two units I ordered. If you are considering this component, you should plan to order extra and to carefully test each unit to ensure you aren't plugging 12v into a circuit that's designed for a less than a third of what the voltage it gets from this regulator. +/- 364% is not an acceptable margin of error for a voltage regulator.

Right out of the pack I checked them with my multimeter. First over had proper voltages. Second was good on the 12 volt but was saying 8 volts on the 3.3 and 5. Was using 12 volts in.

These things get raging hot I'd say over 80c just running an esp32 with wled so what like 50ma? Definitely find something else for your esp32 project. The power switch only cycles power for the 3.3 and 5v rail as well 12v is always hot.

Total dangerous garbage! Guaranteed to ruin whatever device you attach to these. Always test output voltages before attaching to your equipment.