Heath Zenith SL-125-90 Silver Finish Wired Trivolt Clamp-On Transformer Compatible with Most Smart Video Doorbells and Any Wired Chimes and Buttons

I'm very pleased with the Heath/Zenith doorbell transformer. It works perfectly and replaced my very old and failing one. I was motivated to get this when my new August Doorbell cam would not work with the inconsistent and too low output of my old transformer (probably from when the house was built in the 1940's!). Before changing my old one out I confirmed my doorbell chime would be OK with 16v.A small part of choosing this transformer was nostalgia. In my geeky youth I used the get Heathkit electronics and liked building them. Through a twisty maze of corporate spinoffs and acquisitions the Heath & Zenith name are associated with this transformer but that's about all. Heathkit still exists on the web but does not seem connected to this other than the Heath name. So much for nostalgia!The transformer arrived in one of those nasty hard to get into clamshell packages. Inside was the transformer and a pleasingly clear set of diagrams showing how to connect it and how to mount it directly on an electrical box or panel. I think I was a pleased with the directions as with the transformer itself as my expectations on the quality of documentation has fallen a lot over the decades.Doorbell transformers are not exactly high tech. Hooking them up will require basic home wiring skills. In my case the old transformer was mounted next to my electrical panel and I mounted this new one in the same spot. Easy Peasy.A previous (perhaps several removed) made a twisted wire and cloth electrical tape connection to 120 V straight out of the box. I was a little horrified but after killing the power to the circuit I cut away the electrical tape and the old connection fell apart. Putting it together I used appropriately sized wire nuts and new plastic electrical tape for a safer and more secure connection to the transformer leads.Once hooked to the AC I took the existing doorbell wires and connected them to the center tap and the 16V terminal, applied the power and viola! Checking the voltage output at the transformer I got just about 18V so, a little hot. Same at the doorbell terminals. Now my August Gen2 smart camera doorbell works perfectly.I'm very pleased with the transformer. When I pealed back one of the QC stickers on the bottom I saw it was made in China, which is OK and not a surprise. I'd prefer it was made in the USA, but that's just me. But the bottom line is it works great with my August doorbell cam. The old one may have been getting ready to fail, so after 60+ years of service I'm OK replacing it. I'm giving it 5 stars. Working well and being clearly well made I think that deserved.

This transformer is a good replacement.

Works great and ideal for Ring doorbell cameras.

My wife's parents are both extremely hard of hearing and never heard their old "ding-dong" door chime. I bought this transformer and the doorbell that goes with it. Wired them up for the 16 volt output, I didn't measure the actual voltage produced, but the decibel level of the sound was adequate, so everyone is satisfied. Probably built in some third-world country, but everything is these days.

Would not recommend this because it didn't work. With A/C voltage applied, there was no DC output. Just a humming noise. Plus, the mounting bracket is loose when mounted in a standard knock-out. The screw is simply too short to keep the transformer from hanging loosely in the hole.

I had the first generation ring doorbell that ran on a 12 vac transformer, but when i upgraded to the ring pro, i found out that my current transformer was not able to supply the required power.I never bought nor installed a low voltage transformer before, so I figured it would not only be hard, but an expensive task. I have to say that it was neither as i purchased this and installed it within 10 minutes of arrival.What I really like about this transformer is that i gives you three different power options. For lower power requirements, you can set it at 8vac and go up to 16 to 24 vac like the ring pro needs.Once i found my transformer, (in the basement connected to my smoke alarm) i unhooked the old one and simply wired in this one. Anyone with a but of diy knowledge can do this, so no need to hire an expensive electrician. Just look up some youtube videos.As soo as i hooked it up, and turned the breaker back on, my ring finally powered up and started operating perfectly. I am extremely happy that i found this at such a good price, and how easy it was to install. 100% recommend!

The transformer works OK but it has a loud buzz.

I bought this as I had three devices being charged on the old 16v/10 unit. This allowed me to hook my ring doorbells up to the 20v side and my doorbell chime to the 10v side at the same time. Previously, the other transformer was not charging my ring doorbells adequately. The house doorbell requires 10v and Ring DB can take 20v! It all works well now!