24V Transformer 40VA AC Transformer Plug in (1Pack, Without Screw Holes)

Got this transformer to replace an older 16V transformer in my house as I needed up upgrade for a Tapo doorbell unit I received recently. I bought this transformer and a replacement 24V doorbell chime. This transformer seems to work well and performs as expected. Other reviews state that this transformer outputs higher than 24vac. Yes, that’s true but it’s on purpose. There is no regulation on these. It’s a straight step down transformer. The higher voltage will drop for two reasons. 1) current draw (load) and 2) cable run (length). Both of these things have a greater effect on voltage drop than a regulated power supply would have. People who are complaining about the higher voltage measured at the transformer clearly have no idea how this works. They just know enough to know how a DMM (voltmeter) works and that’s it. Additionally, most commercial circuits in medium to high end electronics have a tolerance for what the input voltage can be as well. Usually somewhere in the realm of +/- 10-15% of its highest input value. Moral of this story is, It’s perfectly safe to run this with a 24vac connected device. My credentials are I have a BS in manufacturing, and a PhD in Computer and electrical engineering.

I purchased this for a ring doorbell. My mother didn’t want to set the wiring so we are using the existing wiring in the house already and needed something that would provide 24v output to the device. I tested the device first before plugging it in as my mother got her ring doorbell for free and I didn’t want to fry it. Red Lead on 0v and Black (power) on 24v. The readout was indeed AC, fluctuating from +24v to -24v with a max being +- 30v. The max the ring doorbell can take is 40v so that was great. I checked the connection of the wire for shorts and breaks (resistance) and everything was good. Set it up and it’s working fine. It’s perfect for my needs, though it is a bit bulky causing me to rearrange my plug but it is working and the ring doorbell is recognizing its connected to hardwire. My mother is happy and I got to use my Applied Integrated Technology degree. Win win.

So far, so good! Nice and clean and easy to use.

When I moved in, I upgraded my original (working) doorbell to a Ring camera doorbell. Within 1 year, the Ring stopped working. I suspect the old hardwire doorbell transformer got burned out from a higher voltage draw. Replacing the hardwired transformer would require cutting house power and opening the fuse panel. Instead, I simply bought this 24v transformer, added the doorbell leads to the transformer screws, and plugged it into a nearby socket. The ring doorbell has been working fine ever since.

I purchased the Hotop 24VAC 40VA plug in transformer to replace the 25.5VAC 25VA plug in power supply that came with my Rainbird ESP-Me irrigation controller. The original power supplies are notorious for breaking, and used ones in good condition go for $70 on EBay. The Hotop plug in transformer is a little over-rated for what the Rainbird system needed, but the Hotop was one of the very few 3 prong grounded 120VAC inputs with a 3 wire 24VAC grounded output that I was able to find to match the original Rainbird power supply. I used the 3 wire cord from the original supply and connected it to the 24VAC screw terminals on the back of the transformer case. The measured voltage output from the Hotop read 27VAC with 124VAC input from my house outlet. The original power supply (25.5VAC output) supplied 29VAC, so I'm not worried as the 27VAC is within the range of the 24VAC control valves in my system. Excellent product for an excellent price.

Needed a 24VAC transformer to power my new zone board for my AC unit. This transformers provides power to the zone board and full time power for two thermostats. It is great that it has a built in auto resetting fuse and plenty of power for multiple things at the same time. It does output slightly higher than 24V at just around 27V so make sure what you are using it for can operate at slightly higher voltages. In my case this is driving two zone damper motors, two thermostats and providing operational power to the zone board. Have had it in use now for a little over a month without any issues. I purchased the two pack to have a spare on hand. It is operating in my attic so will be susceptible to the heat of the summer and the zero degree weather of the winter. It does run warm to the touch when in use so be aware if you are using it openly in a living space. So only time will tell how it holds up to all the temperature swings and rigors of 24/7 usage.

I went out of my way to write a review for this transformer after searching endlessly for a compatible AC adaptor for my Google Nest Doorbell Battery version. Google has lots of documentation for the transformer for the wired next doorbell with chime, but nothing for the battery version. This transformer works perfectly with the Google Nest Doorbell, battery version. There were also no instructions so I followed another reviewer here who used it for their Ring camera doorbell and the Google Nest works the same way. Connect the two wires to the two outside posts (0V and 24V), and leave the Ground post blank. After connecting the system up this way and adding the connector provided with my Next Doorbell battery version, the app now shows that it is hardwired for power. The Nest Doorbell battery version will not record 24/7 video, even with a hardwired power connection. You need to buy the non-battery version to get that feature. However, I bought this adaptor specifically so I would no longer need to take the doorbell off to charge so it accomplished that goal.

No funcionó para el timbre ring que sugiere es compatible y al probarlo no paso corriente 0 perdí tiempo sugiero que mejor ofrezcan el original de parte de la compañía ring quien es el fabricante

Works fine with the Ring Doorbell Pro, keep in mind you need to attach the Ring DoorBell Pro PowerPAK unit to the same pins as the power wires just as if this was a standard doorbell transformer. It comes with a three pin out but just used the far Left and far Right pins for the Ring DoorBell Pro wires.

used it for vintage diner wallbox re for jukebox

Had to return as it didn’t work for us

Does not provide the power required to keep a Ring Doorbell 2 charged. Waste of money