Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [probe]

A physical device used to connect an electronic instrument (such as an oscilloscope) to a circuit in order to measure quantities such as voltage, current, temperature, etc. Use in conjunction with related tags such as "oscilloscope", "voltmeter", etc., as applicable.

A physical device used to connect an electronic instrument (such as an oscilloscope) to a circuit in order to measure quantities such as voltage, current, temperature, etc. Use in conjunction with related tags such as , , etc., as applicable.

See Wikipedia's article on probes for more information.

232 questions
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Review request: DIY DC to 50MHz differential oscilloscope probe

Given the cost of proper differential probes, i've decided to make my own. The requirements are: DC to 50 MHz 3db bandwidth A few selectable input voltage ranges, from 3V pk-pk to 300 V pk-pk Better than 1/500 common mode rejection ratio A…
jms
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What is the name of this springy type oscilloscope probe accessory?

Exactly what it says on the tin. How is this pictured accessory called? The obvious place to look for a name would be the probe manual, but it looks like they decided to add the accessory to the package after making the manual, since it's not on…
AndrejaKo
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Where to leave the test leads on a Fluke multimeter

I think this is somewhat of a "trade secret". Being a software engineer for embedded devices myself, I often find myself using oscilloscopes and multimeters. I have always wondered about my Fluke 87-V and all flukes before that. They have these…
Stijn
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CRT Oscilloscope - part of the plot is missing

I picked up an old METRIX OX 720 oscilloscope. I replaced 2 capacitors that went up in smoke. Once restarted, here is the signal I get. The vertical part of the signal is missing. It is the same for both channels. Do you have an idea of the…
FrancNovation
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How do you attach an oscilloscope ground spring?

Sometimes you need to ensure that your oscilloscope probe ground lead is not creating measurement error such as ringing and overshoot. In various forms, I have seen (and successfully used) a ground spring for measuring a circuit. I have shamelessly…
W5VO
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Why are oscilloscope input impedances so low?

My question is two-fold: Where does the input impedance come from? I'm wondering where the input impedance of your average multimeter or oscilloscope comes from? Is it just the input impedance to the device's input stage (such as an amplifier or…
PersonWithName
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Is this a good design & layout of an active differential 'scope probe?

This question is an extension of Homebrew differential 'scope probe. I thought I should make this a new question though. I need to measure a 100Mb/s LVDS signal to check its integrity. I will try to get hold of a 'scope with a 600MHz bandwidth, but…
Rocketmagnet
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What do you use to probe small circuits quickly?

I still haven't found a really good solution for grabbing tiny surface mount stuff. Alligator clips are definitely way too big. Mini-grabbers like this with the spring-loaded hook are an ok solution for bigger stuff, but no good for little surface…
endolith
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High speed passive probe - contradiction between authors or different points of view?

In a document Hiscocks et al. describes some basics of Oscilloscope probe theory. The document is very understandable and seems coherent. Notice in particular that for him, the bad guy is the parallel capacitance of the coaxial cable and of the…
MikeTeX
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About Oscilloscope Probing Philosophy

Recently, I read Tektronix's Probe Bandwidth Calculations. It point out that Tektronix and Agilent have different probing philosophy: There are two schools of thought on what an oscilloscope probe should actually display on an oscilloscope.…
diverger
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Is it acceptable to use decoupling capacitor ground pad as ground for oscilloscope probe?

If one were to probe with an oscilloscope using the short ground spring clip attachment, and use the ground pad of a decoupling capacitor as the ground, would the measurement be thrown off at all by currents moving to ground through the capacitor?…
wdbwdb1
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Does this experiment show that Kirchhoff's Law hold when there's a changing magnetic field involved in a circuit?

In this video, the electrical engineer and youtuber Mehdi Sadaghdar (ElectroBOOM) disagrees with another video from professor Walter Lewin. Basically, professor Lewin shows in an experiment that if we have two different resistances connected in a…
Hey Hey
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Why doesn't this DIY high-speed probe reflect signals?

I am reading The Art of Electronics, page 809 and 810, where they show this probe: Figure 12.32. Probing digital signals: […] Simple 20× passive “probe” for 50 Ω ’scope input: 953 Ω series resistor to coax This is a DIY probe made out of an RG-178…
mFeinstein
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Good uses for 1:1 probe

We all know why using a properly compensated 10:1 probe is a must when viewing MHz-speed signals on a scope with a 1 MOhm input impedance. Now who can supply a good use for a 1:1 probe? These probes have not found much use in my lab. The only thing…
Zane Kaminski
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Homebrew differential 'scope probe

I may be able to get my hands on an old 600MHz LeCroy oscilloscope. However, it doesn't have any probes. Is it feasible to make an active differential probe for it using a high-speed op-amp, like the THS3201DBVT? It has a 1pF input capacitance,…
Rocketmagnet
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