I'm using an ecobee3 lite with a pellet stove, which means having to power the smart thermostat from a transformer. This is working perfectly for that purpose. I first tried a Wuyelin transformer but did not like how warm it got. The Elk is easily 50% cooler if not more.

Works great.

All ok.

Finalmente encontré el producto justo para alimentar un timbre con cámara Ring 1 después de haber intentado hacerlo con otro tipo de transformador para eliminar el uso con batería y tener que cargarla con cierta frecuencia

My Ring Doorbell2 was discharging the battery that comes with the Doorbell 2 system very quickly. It seemed that the battery would be totally discharged within about three weeks. At first I purchased a 14 VAC transformer from Amazon, but the battery was losing about 5 % of its charge per day even though the transformer was wired directly to the Ring Doorbell 2 system with the use of a 25 ohm, 50 watt resistor as recommended by Ring documentation. Therefore, I decided to buy this, 24 VAC transformer, and connected it to the Ring Doorbell 2 system with the 25 ohm, 50 watt resistor using a pair of 18 gauge wires that are about 20 feet long. By slightly reducing the sensitivity of the motion detector, our Ring Doorbell 2 system has been running for about one week with the battery charge level between 94% to 100%.. It currently has a battery level of 99%. Before buying this transformer, I was seriously considering, not using the Ring Doorbell 2 system as part of our home security system.

I used this to replace an old blown standard transformer to power my nest doorbell. It works exactly as it should. I had a short in the wire i couldn't find that blew my old transformer and this handled the overload perfectly. It helped me trouble shoot the issue. unplug after the short, plug it back in, powers back. pick it up if you are looking to run a smart doorbell.

Bought this item for my RingPro doorbell - super easy to install and RingPro has been working awesome without issues since I installed this transformer..

Pretty easy. The packaging shows you what to do with the GND wire (nothing), which I was concerned about immediately. It comes with a longer screw that you can use after removing the screw from your outlet to secure it in place, just in case it gets bumped and wanted to fall out. It is pretty heavy and a little awkward, so I was happy for the extra screw to make sure it would stay put. I'm not an HVAC professional, so I'll just outline my experience. I installed an ecobee4. From my original thermostat, I had a Rc, Y1, W1 and G wire. I had an extra blue wire running to nothing, but using a $20 multimeter I bought, I found it was only running 8-10 VAC. I first turned off the whole system. I live in an apartment complex so, being unfamiliar with HVAC, I A) didn't know exactly where to look to see if I could use that blue wire at the furnace for a C wire and B) didn't want to be seen outside jacking with the complex, and my neighbor's possibly, HVAC stuff. Anyway, I turned everything off. I checked the wires with the multimeter. Initially I'd installed a Nest because I didn't have a C wire and when I turned everything off, the Nest did not say that it needed to be connected to power, so I was worried. I worked for a little longer removing wires VERY carefully and finally realized that I had that mulitmeter and checked the voltage on the wires to find there was nothing running to them. That made everything much more relaxed. I removed all the Nest stuff, then ran the transformer cable up which I just used some extra wire I had. It was nothing special. It had a accessory plug on the end. I have no idea what it was originally for, but I just clipped it off and stripped the wires to where I needed. I attached it to the AC terminals on the plug and, just to test without installing anything or doing anything at all really, plugged the wires into the C and Rh terminals. I got no response. So, hoping that I didn't just fry the thing (which you can't if you're using the correct voltage right? I don't know), I moved the Rh wire to the Rc terminal. It powered on and went through it's thing. I took everything out and put it up on the wall with the cables in place. I attached the easy cables (Y1, W1, G and C). The problem with Rc became that the hole for the wire was really small to only allow for the one wire. The cable from the transformer is threaded. I couldn't get them both to go in. So, I ended up stripping the original Rc, which was a solid wire, and wrapping the threaded wire around the base. Pushed the Rc lead in and made sure the surrounding wires are in tight enough that nothing is exposed to touch the part of the Rc assembly that needed to be left bare to connect the transformer wire. Turned the power on and plugged the transformer in and it power up just as before. It has rebooted once, but I was messing with Homekit, and I think it actually just crashed. It's been fine for the past 5 hours. I looked around for step by step for my wiring, and hope this helps anyone in a similar situation.tl;dr: It works well for the ecobee4. Test it with just the transformer first on Rc or Rh and C to make sure it gets powered on. You'll not break your furnace transformer that way. You might have a hard time with the wires into the ecobee backplate being too much to fit into the receptacle. You can wrap one wire around the other and put the unwrapped one into the backplate. Be sure that it (joined Rc/Rh) won't touch the other wires. Otherwise, it's been great. Oh! I was also super worried about having the external transformer wire connected to the same wire that was initially providing power to the system (as stated, the wire from the transformer is wrapped around the original Rc wire), but I checked it with the multimeter afterward and it still ran the same 26 -29 VAC.

Item being reviews: Elk TRG2440 24VAC, 40 VA AC Transformer with PTC FuseI installed this 3 months ago to use with Ring Video Doorbell 2. It is doing the trick perfectly.In the posted picture you can see the Elk device and a resistor that I attached to the side to comply with Ring requirements.The Ring Video Doorbell 2 says that the battery can last about 3-12 months depending on how much motion is involved and how far you set the motion sensor to detect. It says if motion is high than it will last less than 3 months. Sure enough, my battery was fully charged when installed, then died within 2 weeks of my high motion location uploading a video every minute to the Ring cloud. So I bought this Elk 24v transformer. The ring documentation says that you must purchase a 25 ohm resistor. So I bought the following resistor to work with this Elk device:Uxcell a12050500ux0030 Aluminum Case 50W 25 Ohm Chassis Mounted Wirewound ResistorAfter 3 months of sending 1000's of video recordings to the Ring cloud I am happy to report that this device is keeping the battery at 99% and the Ring device has not reported any failure from the Power Source, it has report of Power Status of "Very Good" which means it is fully charged and the correct voltage.

This met my expectations for use to provide a c-wire connect for ecobee3 thermostat power and had no issues with this product for the applied function for thermostat poweri do recommend this product