ZHENGXI Isolation Transformer 120V to 120V,500W Transformer Voltage Converter, 2 Output Sockets

This is an isolation transformer, which may or may not solve problems depending on what they are, and people are inclined to leave a bad review if this doesn't solve their issue. So keep that as a grain of salt. About the transformer, wow, I am so surprised of the quality and value of this thing. I got the 500W one, and it's pretty heavy, because it comes with a giant toroidal transformer inside. It also includes some line filtering electronics, a breaker, and simple MOV-style circuit protection. MOVs provide marginal protection that are designed to explode on a surge, and it would have been nice to see better protection integrated, but I didn't purchase this transformer for surge protection, so it's just an added bonus. For what it's worth, I put these isolation transformers on some ATC SCM25A Pros (the first version) in an attempt to reduce a loud buzz that the linear transformers in them used to make when load was placed on the same circuit in my home (i.e. a water kettle). After putting two of these between each monitor, the buzz went away completely. This has been an issue with these monitors that even ATC has been struggling with, and these isolation transformers solved the issue! This review is not influenced by this good result, but I thought I would share regardless :)

At the four month of ownership point, and using primarily to isolate defective power boards and supplies to scope and repair, I've found this isolation transformer to perform as advertised and correctly isolate the DUT (device under test) from the earth grounds. Based on other reviews I pulled the lid after receiving the product and checked for correct ground isolation and for soundness of connections and general built quality. No complaints. The main reason I bought it was to isolate DUT's to prevent ground loops and damage to my scope when not using differential probes. I normally run it behind a Variac which the DUT are connected to. While investigating defects I've blown up a couple boards with no adverse effects to the product. Having the outlet in the back isn't a problem since I have the product on a high shelf and the Variac is plugged into it and that product has front panel outlets for DUT. It generally runs between 4 and 8 hours per day. I am not a pro, rather a retired machinist who enjoys electronics. I note the price has held steady between when I bought it and the time of this review at ~146. I'd recommend this product.

Nice and Solid! Keep in mind if used along with Variac, to place first because it counts with low voltage protection. Any way, anything done in your workshop, is done with caution to avoid electrical hazard!!

I’ll start with, this is a five star item in its function. I would order this again without hesitation. It has resolved the noise issue I had on my ground line caused by an LG refrigerator. The only challenge was the packaging, which would have been adequate but the box was too big for the foam inserts allowing the item to move and causing some minor damage (that was easily fixed.)

Investigated many isolation transformers. I like the external design, features, and the robust weight of this one. Upon receiving I powered it up and observed that it has a soft start feature which is a big plus when you have a toroidal transformer. Toroidal transformers have large initial current surges until the magnetic field is established in the core of the toroid. Those surges can pop fuses, which can be an inconvenience. There is an elaborate choke and capacitor noise suppression filter on a circuit board. I would have liked to see a pair of standoffs supporting the board in the middle against shipping vibration and normal handling because of the weight of the choke coils. Also there was no manual and schematic. I opened the case and loved the robustness of the build, the proper layout and the lacing and routing of the wires. Now this transformer provides true and complete electrical isolation because the ground pins on the outlets are not connected to the chassis or the incoming power line ground. This is essential when using a solid state oscilloscope. The electronics under test must be plugged into this isolation transformer so there is no backfeed of high voltage thru the ground to the scope, thus frying the scope. At a later date, my friend and I ( we are both engineers and he bought the same unit) will test for noise suppression thru the outputs by using a scope at the outputs and an AC brush type motor at the input and see what the noise filter can do. So far, we are both impressed by the quality of the build and great bang for the bucks.