Tamper Detection With Time-Domain Reflectometry

For certain high-security devices, such as card readers, ATMs, and hardware security modules, normal physical security isn’t enough – they need to wipe out their sensitive data if someone starts dr…

Hackaday

I'm thinking about using time-domain reflectometry to find the fault(s) on a string of Christmas lights.

#Electronics #TestEquipment #TimeDomainReflectometry #TDR

Relatively recently, I got interested in time-domain reflectometry, which is essentially just sending a pulse down a cable and measuring the amount of time for its reflection to return.

It's useful for testing long cables and finding where there's a break.

I bought a little device that plugs into my oscilloscope and provides a USB-powered low-frequency oscillator for doing this. (Total kit cost is <$400.)

It also provided a good "object lesson" by showing me that the signal traveled through some coaxial cable only at about 66% of c, reminding me about that last part of its definition as the speed of light *in a vacuum*.

That's only about 1.9 × 10^8 m/s.

According to a quote from "Computer Networks - A Systems Approach (5th Ed)", a signal through copper wire could propagate at 2.3 × 10^8 m/s and through optical fiber it's just 2.0 × 10^8 m/s.

https://en.wikipedia.org/wiki/Time-domain_reflectometer

#TimeDomainReflectometer
#TimeDomainReflectometry
#TDR

Time-domain reflectometer - Wikipedia

Kabelbreuk vinden met TDR

Hoe lokaliseer je een breuk in een kabel met behulp van time domain reflectometry. Meer informatie vind je op: https://www.meezenest.nl/mees Mijn Engelstalige kanaal: @MeesElectronics Donaties: https://ko-fi.com/meeselectronics of maak direct een donatie over naar: NL91 ASNB 0708 7056 77 t.n.v. M.T. Konstapel (BIC: ASNBNL21) Free Broll by Videezy Music: https://www.bensound.com/royalty-free-music Sound effects: https://bigsoundbank.com

MakerTube

Repairing a broken cable using TDR

https://makertube.net/w/ofwv6uUrvVuends7XEcXB4

Repairing a broken cable using TDR

PeerTube