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Electronics => Beginners => Topic started by: FriedMule on February 04, 2022, 06:32:47 am

Title: Can this be used a probe isolator to an oscilloscope?
Post by: FriedMule on February 04, 2022, 06:32:47 am
Was on mouser and stumbled upon this DC-3GHZ isolator fairly cheap, can it be used as an isolator between the scope and the standard probe?

https://www.mouser.dk/ProductDetail/Mini-Circuits/Z7550-BMBF+?qs=DRkmTr78QASgPck0XOSDow%3D%3D (https://www.mouser.dk/ProductDetail/Mini-Circuits/Z7550-BMBF+?qs=DRkmTr78QASgPck0XOSDow%3D%3D)

Datasheet: https://pdf1.alldatasheet.com/datasheet-pdf/view/1324771/MINI/Z7550-BMBF+.html (https://pdf1.alldatasheet.com/datasheet-pdf/view/1324771/MINI/Z7550-BMBF+.html)
Title: Re: Can this be used a probe isolator to an oscilloscope?
Post by: tooki on February 04, 2022, 07:48:18 am
But how is that isolated? On its schematic, it’s clear it’s not galvanically isolated.
Title: Re: Can this be used a probe isolator to an oscilloscope?
Post by: fcb on February 04, 2022, 09:13:40 am
Quote from: FriedMule on February 04, 2022, 06:32:47 am
Was on mouser and stumbled upon this DC-3GHZ isolator fairly cheap, can it be used as an isolator between the scope and the standard probe?

https://www.mouser.dk/ProductDetail/Mini-Circuits/Z7550-BMBF+?qs=DRkmTr78QASgPck0XOSDow%3D%3D (https://www.mouser.dk/ProductDetail/Mini-Circuits/Z7550-BMBF+?qs=DRkmTr78QASgPck0XOSDow%3D%3D)

Datasheet: https://pdf1.alldatasheet.com/datasheet-pdf/view/1324771/MINI/Z7550-BMBF+.html (https://pdf1.alldatasheet.com/datasheet-pdf/view/1324771/MINI/Z7550-BMBF+.html)
Impedance matching transformer. No isolation.
Title: Re: Can this be used a probe isolator to an oscilloscope?
Post by: radiolistener on February 04, 2022, 12:21:23 pm
there is no isolation, it has direct connection between input and output ground
Title: Re: Can this be used a probe isolator to an oscilloscope?
Post by: jonpaul on February 04, 2022, 01:00:01 pm
Hello: Unclear your objective:

Isolate scope input 1 M from mains etc?

Pass DC...HF and convert 75 Ohm ><50 Ohm?

The Mini Circuits part is a Zo match with DC bias link eg for cable TV use. The transformer wthin has a LF point determined by the core, area and number of turns.

This should be designated for example as 10 MHz...3 GHz 75><50 Ohm match with DC bias link"

It is NOT a DC-3 GHz device despite the specs!

Suggest to read the Tektronix Circuits Concepts book "Oscilloscope Probe Circuits Concepts" to understand the different scope input and probe options.

https://w140.com/tekwiki/images/6/62/062-1146-00.pdf

If you can define precisely the system freq,min max (eg DC-100 MHz?)  and isolation needed the forum can assit you better,

Bon Chance,

Jon