Isolated Oscilloscope Probe

Petite and practical

However much you might wish for an oscilloscope with electrically isolated inputs, it’s hard to justify the cost for personal projects. Even differential probes, which (within certain limits) enable voltages to be measured without reference to ground, often cost the private user more than a complete scope does. So what can you do when either safety considerations or the nature of the task in hand require the use of isolated connections to your oscilloscope?

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Materials

www.ti.com/product/iso124

www.ti.com/product/amc1200

PDF of print layout

Component list

Component List
Resistors
(SMD 1206)
R1 = 10?
R2 = 9M?
R3 = 1M?
R4 = 100 k?
R5,R6 = 1k?

Capacitors
C1–C4 = 100nF (SMD 1206)

Inductors
L1 = 10µH (SMD 1206)

Semiconductors
U1 = AduM5242 (SOIC-8)
U2 = AMC1200 (SOP-8)
U3 = OPA333AIDBV (SOT-23)

Miscellaneous
CON1 = BNC plug, panel mount
CON2,CON5 = 3-pin pinheader, 0.1” pitch
CON3 = mini-USB receptacle
CON4 = 2-pin pinheader, 0.1” pitch
CON6 = BNC socket, panel mount
PCB # 130297-1

Discussion (0 comments)

mr_goll 7 years ago

Would love to see the schematic for this design , although seeing the BOM is a really nice touch, thank you. The need to raid my piggy-bank, makes me wonder if I can probably just wing it; despite the potential jeopardy!

Kerry Wong recently came up with a simple isolated probe design using an INA117 isolated differential amp, powered by an LT3463 (to provide the required +/-15v power) and with a three way resistive divider (probe floated mid-point) to scale the hot-side, results looked impressive.

Paul J Moore 5 years ago

"Downloading of this magazine article is reserved for registered users only."... sign up and register and then: "Downloading of this magazine article is reserved for Elektor GREEN and GOLD members only. Click here to manage your Elektor memberships." ( PAY US!)- oh well, just my time wasted.

StTh 5 years ago

Is it possible to buy this finnished ?

Michael Margolese 10 months ago

https://www.elektormagazine.com/news/circuit-diy-compact-isolated-oscilloscope-probe

3 Comment(s)

N. Christopher Perry 2 years ago

According to the 'Construction' section I should be able to download the PCB layout from the 'project page', which is the 5th link at the end of the article. The link is broken and I don't see any additional data on this page. Where can I download the PCB layout?

0 Comment(s)