Modern isolation transformer

[Mosaic]

Hi,
I am thinking of adding one of these to my workbench. (I am getting a bit of sponsorship so i am looking at optional items for the workshop)
https://www.radioelectricindia.com/isolateddw.htm
I wanted to get a bit of advice as to a suitably rated gen. purpose 125V, 60Hz unit.

My immediate use would be to isolate my o'scope when probing ground referenced circuits.

 

[ronsimpson]

I often isolate my circuit and not the scope.
I have isolate my scope. Not usually.

 

[dr pepper]

Good idea.

As well as that if your uisng a usb 'scope then get a usb isolator, and a seperate 5v supply for the usb, make sure the supply has good isolation, and its negative isnt grounded.

 

[KeepItSimpleStupid]

Honestly, isolate what your fixing, not the scope or at least not the big metal chassis scopes. Metered helps a lot.
I made a 3A non-isolated variac connected to a 1200 W isolation transformer. I had the switch arranged so it would go through the 3A variac, off or isolation. I really didn't think ground through, but I also put binding posts on the unit and a fuse on the front. It's worked fine since my early teens.

Most of my uses were on old TV chassis that were not isolated. The second use, was bringing up power amplifiers where isolation generally wasn't needed.

 

[Mosaic]

Good idea.

As well as that if your uisng a usb 'scope then get a usb isolator, and a seperate 5v supply for the usb, make sure the supply has good isolation, and its negative isnt grounded.

That sounds possible to DIY...

 

[KeepItSimpleStupid]

USB isolators are kinda problematic. One is differnt logic levels from 1.1 to 2.0 and the amount of available current due to USB, DC-DC donverters or an external supply. I own two. One will suport 1.1 with jumper changes. 470 seems to be the fastest speed.

 

[dr pepper]

If you diy one let me know, the power supply isnt so much a problem, getting an opto to work as usb freq's is a challenge.
I suspect commercial isolator chips are inductively coupled.
You can use a smps brick off the mains instead of a dc to dc converter.

 

[KeepItSimpleStupid]

Some use the USB icoupler from analog devices.