MGT1640 TRANSFORMER 16V 40AH

I've been using this transformer to power a doorbell camera and a doorbell for a few years now and it has performed flawlessly. The power output rating is accurate and steady even under load.

I wanted to clariify some incorrect information posted in the answers section. I have also asked Amazon to have the vendor correct an incorrect product picture which I believe has lead to erroneous assumptions of this item. This, coupled with very little info from the vendor will lead to errors. c When it comes to messing with electricity, the information should be accurate or someone will either be hurt or electronics will be damaged. First off: This is indeed an AC Transformer. It's really a "step down converter". It converts 120v AC to 16v AC. (not DC). AC = Alternating current. North America standards are 120v while much of the rest of the world uses 220v. v=Volts. DC = Direct Current. Many electronics devices eventually need power to be converted to DC and so for most of the electronics you buy, the AC Adapter really is converting 120v AC to a much lower XXv DC. Why do we have AC vs DC power? Simple: DC has more "juice" per volt, but the "juice" drops off quickly, the longer the distance. AC can travel long distances and still maintain the "juice". This is a laymen's term explanation. Now: There are actually some electronics that require low voltage AC. This is where a transformer like this comes into play. Alarm panels like the description says often need low voltage AC power. I bought this item to power my new Ring Pro Doorbell which is a slimmer version of the Ring Doorbell 2 since it doesn't have a battery to help power it. Ring, unfortunately makes it sounds too simple and doesn't provide enough power details to help the average homeowner install their device. They simply state "remove your door bell and install ours". The problem is that 90% of the doorbells installed in modern homes only come with a 16v AC transformer that delivers 10AH = 10 watts of power. This is enough to power the doorbell but not enough to properly power the wi-fi chip and video camera components. The Ring App doesn't tell you why it won't connect and it frankly was a easter egg hunt to find this simple info on their support site. For a $300 doorbell, Ring should have included a replacement door bell transformer in the box or a voucher to order one at no charge. In either case, after a ton of research, I ordered this item. Unfortunately, based on a lack of proper specs in the vendor's description and erroneous info posted by fellow Amazon shoppers, I ordered a different transformer but by the time I tried to cancel the order for this item, it had already shipped (Amazon is too efficient sometimes.. :)) Needless to say, if you need an AC Transformer to power your Ring Door Bell, this item has been powering mine for more than a month without issue. I highly recommend it. I have also posted a picture of the Transformer that I received. You will notice there are 3 screw terminals: 2 of which labelled AC (Power needs a loop but DC has a + and - side - AC power doesn't care for most low voltage items)..The other screw is a ground screw which is required if the device are are connecting is grounded. Also to note: My builder (home is 2004 build) used really thin Cat3 cabling for the doorbells instead of the traditional heavier gauge "bell" or "thermostat" wire.. I am happy to report that I have no issues with this thinner wire holding enough current for the door bell and video camera. I hope this review helps other buyers or either a Ring device or other devices that need an AC transformer. (BTW: Ring says if you connect their doorbell to a DC transformer - you will fry it so be careful with the details on whether your device needs an AC or DC transformer).

This item works fine, actually great, but it’s worth noting that what I received differs a little from the spec and picture for the listed item. While the product number embossed on the item and on the box matches the listing, it’s actually a 16.5v device, not the 16v in the listing. There are also 3 terminals, one for the ground, as opposed to the 2 shown on the listing. And it’s a slightly different shape so, again, not what was pictured. To be fair, what was sent has a green LED to show it’s working, while the one in the listing did not have that feature, a clear benefit. I’d purchase again as it meets my needs but I was targeting for the technical specs in the listing and that is not what was sent. I was able to make it work for my needs but others may want strict adherence to the listed spec.

When we needed to replace a defective transformer on our Honeywell Vista 20P Security Control Panel, we chose MG Electronics based on their high quality and cost effective products. Installation was simple and took less than one minute. A green LED illuminates when power is on. *** WARNING *** You MUST disconnect AC electrical power to the duplex receptacle before you attempt to plug or unplug the transformer. All duplex receptacles allow for a single screw located in the center of the receptacle used to secure a metal or plastic faceplate. This moderately heavy (1.57 pounds) transformer uses a single mounting screw which attaches to the center of the duplex receptacle. Because of this, the faceplate cannot be secured to the receptacle and will hang freely until the transformer is secured. Therefore, the faceplate may slip onto the plugs of the transformer when either plugging or unplugging the transformer. If the faceplate is metal and the AC power is on, the faceplate will `arc' and create a short, and possibly tripping the associated circuit breaker. To avoid this, make sure the AC power is OFF when plugging or unplugging the transformer.

Was easy to install. I got this to work with a Ring Doorbell Pro. It worked well for 4 months, but now outputs only 10 volts. The doorbell requires 16 volts, so now the doorbell isn't working.

Our alarm system stopped working after a power surge. I was hesitant to call an alarm technician so I searched online for possible causes. An error light was illuminated on the alarm circuit board. Someone suggested checking the transformer that supplies power to the alarm panel. The wierd thing was trying to find that transfomer. It was installed in the garage, on the ceiling, next to the overhead door machine. I guess the installer hid it there to keep someone from tampering with it. In any event, I replaced it with this one, reset the panel and we are good to go again. $20 fix beats a $150 service call.

I bought it to install the Ring 2 camera, as a direct replacement of our house's original transformer, which didn't have enough power. The installation was straightforward, connecting the two wires to this piece. It's working very well for the hardwired installation of the Ring and it stays charged at all times. Will update if somehow this fails in a short timeframe. So far, so good.

Transformer powers digital control box (6021) of Marklin HO model train; have 2 units. Correct AC voltage (~18V) and works great at much reduced cost from official transformer (eBay only). Also tried 50VA unit, but AC voltage too high.