Teardown & Repair of a Sencore PR570 Variable Isolation Transformer & Safety Analyzer

In this short episode Shahriar performs a teardown and repair of a Sencore PR570 variable isolation transformer and safety analyzer. One of the LCD segments of the unit does does not display.

The teardown of the unit reveals a variable auto-transformer followed by an isolation transformer. The main board contains all of the circuitry for performing over-current protection, ground leakage current monitoring and other safety analysis software. The LCD problem is easily corrected by cleaning the contacts of the LCD module. A quick experiment on an Apple iPhone charger is used to verify the instrument functionality.


  1. Mukesh Tolani says:

    hello very nice and informative blog. There are some special purpose transformer also known as special or auto transformer Transformer Manufacturer In India

  2. Eileen says:

    Thanks , I’ve recently been searching for info approximately this subject for a while and yours
    is the best I’ve came upo till now. However, what about the conclusion? Are you positive in regards tto the
    source? https://Plus.Google.com/+Olympiaseo/posts/UdFf8Q1FcYs

  3. Leopold Delouche says:

    Hey Shahriar and all, this piece of equipment looks great!
    As it happens I am looking for a device with the same functionality but I am having a hard time finding anything like it. Ebay seems empty or overpriced and I can’t find any new models on the classic test & equipment sites. Something close would be the 9801 from BK Precision but that is way too much precision for me. I am thinking I would be better off using an isolation transformer and a variable transformer but that is a lot of equipment to have.
    I would love to have any input on the subject. Thanks.

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