MEAN WELLUltra Slim Step-Shape 1SU DIN Rail Power Supply, 12V 1.25A 15W - HDR-15-12

Good choice for limited spaces

Very handy to have such a small, DIN rail-mount power supply; several VA available

Very thin low power output supply. It only takes up about 3/4" of rail for the 15W (smallest) version. I dialed it down to 10V for my application and I saw that 9.5 was also within the adjustment range.

Tidy way to get some 12v signal voltage into an enclosure for triggering small relays and such.

This is a very nice and compact power supply, however the rise time of 80ms is longer than most comparable supplies. This measurement is how long the voltage takes to reach the stated output after the “setup” time which is the delay after applying power before it turns on. Depending on your equipment this can cause trouble. I intended to use these to power an ESP32 based GPIO controller and with this power supply after it’s sat for more than a few minutes the ramp up to full power is slow enough to confuse the ESP32 into going into download firmware mode rather than starting up normally. Additional quick power cycles work fine, but it seems that once the internal caps in the power supply have discharged completely it just takes too long to ramp up to the full voltage output for my application. It works perfectly every single time with a meanwell DR-15-12 which has a rise time of 50ms or a MDR-20-12 with a rise time of 30ms. This is probably not going to be a problem for most equipment but if you have strange issues at poweron after it has been off for more than a few minutes then this might be the issue and you should try one of the others. It is definitely a problem for at least some ESP32 based devices.

This 12v dc power supply has been powering my Lettuce grow controller for months now. Love the capability of it and look forward to using it to power more things. Will update review if anything should happen.

This is currently housed in a steel box near the top of a 25'-high gym. The unit has remained stable for several months now. Thermally, little heat is noticed. It's on 24/7/365, but there's only a draw on it a couple hours a week, and that draw is around 300 mA. It's used as the PSU for a DIY 0–10V/DMX switcher design, driving both a DMX converter and a relay board.

I love these meanwell power supplies, I have at least 15 of them in use. Consistent power, and cool operation.