Author Topic: HDMI Surge Protection  (Read 1896 times)

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Offline Raj

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Re: HDMI Surge Protection
« Reply #1 on: September 06, 2018, 04:24:28 pm »
Just protection from interference. Won't protect from lightening happening on top of your house. Cause my guess is, it's just an inline ferrite and some tvs diodes.

Better to buy a better cable if you are facing some kind of interference problem like occasional disconnections as if cable was loosely connected.
 

Offline Ice-Tea

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Re: HDMI Surge Protection
« Reply #2 on: September 06, 2018, 05:36:11 pm »
There are dedicated ESD protection ICs for HDMI/DP/whatever. I'm sure it does *something* for a little surge as well. But to stop a 'real' lightning strike you'd probably need something more beefy, thus more capacitance and thus you can kiss signal integrity goodbye.

In conclusion: if it works, it probably doesn't work.  :-DD
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Offline T3sl4co1l

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Re: HDMI Surge Protection
« Reply #3 on: September 06, 2018, 06:41:42 pm »
I don't see anything about filtering?  It's probably just an array of ESD diodes and two connectors!

What would you need such a device for?  Dealing with shitty (poorly shielded) cables?

BTW, the specs are probably read directly off the TVS datasheet, meaning it can withstand those stimuli.  That doesn't mean there's any actual effectiveness in protecting equipment.  (Preferably you might use two, one on each end of a long cable, to protect source and load.  You definitely wouldn't put it in the middle as an extension between two cords.)

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Offline jchamblee

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Re: HDMI Surge Protection
« Reply #4 on: September 06, 2018, 07:19:18 pm »
Thanks for all the responses!

I don't need them for filtering at all, I use good cables. The problem is lightning hit the house and destroyed the HDMI outs of all my equipment. The inline protection circuit saved the power supplies. All the devices work great if I choose another output, like Component, or S-Video. I was just looking for something to maybe save the devices if there is a next time. There doesn't seem to be anything from a reputable source, at least not one that I have heard of.

Thanks,
J
 

Offline coppercone2

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Re: HDMI Surge Protection
« Reply #5 on: September 06, 2018, 07:39:52 pm »
x2y corporation has interesting app notes about using their capacitors for protection in connectors
 

Offline T3sl4co1l

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Re: HDMI Surge Protection
« Reply #6 on: September 06, 2018, 07:55:52 pm »
Hit the house directly? :O

There's not much you can do about that -- that's up close EMP and it'll zap pretty much everything with more than one cable attached (and even then maybe).

The problem is, EMP induces voltage (and therefore where a loop is formed, current too) on the lengths of cables.  Where a current drops across a cable, some of that current divides into the signal lines, and that's how ports get fried.

A surge protector will account for signal currents at the connector, but those currents continue into the circuit, dropping voltage across internal traces as well.  It might help, it might not. :-\

To solve that, you need to route cables as if there were only one cable connecting to each device.

This implies a hub-and-spoke structure.  Not very convenient for the most part, where, say, you have a triangular loop between the cable box, TV and their power cords (or any other example where signals and power travel separately).  Shrinking the loop to about zero area means the cables have the same voltages induced on them along their lengths, which cancels out the voltage between cables, and no surge current flows.

Or, you probably have Ethernet cables routed through the house along different paths from the mains wiring; or even if you do, you probably don't have the router/switch at the panel.

Mains wiring is normally a hub-and-spoke topology, which is a great start at least.  Matching the same topology, in the same location -- so that every circuit that runs from the panel, has a network cable directly alongside it, and the outlets are similarly paired -- should be a big help.  Not saying that's a guarantee, or that it's easy to do once everything is already in place, sadly...

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Offline jchamblee

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Re: HDMI Surge Protection
« Reply #7 on: September 06, 2018, 09:44:14 pm »
Yeah, lightning blew a 6 inch hole in the chimney cap, and exited the complete other side of the house through stucco and into a metal fence top, then out the metal fence into a retaining wall. It killed a breaker, 3 cameras , NVR ,48 port poe switch, 4 tv's that didn't have surge protection, landscape lighting,pool lighting, gate controller, Generac controller and ECU, 2 Surround receivers, Theater projector, blue ray player, all the cable boxes, 30' HDMI cable that ran to the projector.  I'll post pictures if I can.

It's what got me thinking about HDMI Protection. I just figured they may ground the shield as most surround receivers are not grounded. Although I am surprised anything in the house survived.

Thanks for everyone's comments.
-Jason
 

Offline jchamblee

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Re: HDMI Surge Protection
« Reply #8 on: September 07, 2018, 02:26:16 pm »
Picture of the chimney and wall. These location are at least 100' from each other.
« Last Edit: September 07, 2018, 02:31:27 pm by jchamblee »
 
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Offline T3sl4co1l

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Re: HDMI Surge Protection
« Reply #9 on: September 07, 2018, 04:17:09 pm »
Damn... glad it didn't start a fire, very lucky!

Tim
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Offline coppercone2

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Re: HDMI Surge Protection
« Reply #10 on: September 09, 2018, 04:45:15 pm »
has anyone here worked on electrostatic volt meters for maybe detecting a high probability of strike? maybe combined with some acoustic microphones to detect nearby lighting, and at least disable some systems with smart power strips?
http://bibliotheek.knmi.nl/knmipubIR/IR2013-01.pdf
« Last Edit: September 09, 2018, 05:04:58 pm by coppercone2 »
 

Offline james_s

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Re: HDMI Surge Protection
« Reply #11 on: November 03, 2018, 09:43:11 pm »
Wow that's pretty spectacular, I always find cases like this fascinating, we don't get much lightning out here so it's rare although I did once fix a dishwasher control that had been damaged by a nearby lightning strike out in a region where overhead wiring is common. The fuse had been vaporized, all that was left was a black splotch on the PCB and two splayed out twisted lead wires. It blew up the MOV and blew the thermal fuse in the transformer too.

Trying to protect gear from a direct strike to your house is a bit like trying to make a bulletproof vest that will stop a round from a 75mm Howitzer. There's just so much energy involved that it's pretty much futile, beyond making sure all the external metal is well grounded or installing a lightning rod your best bet is to unplug your gear during a storm.
 

Online Gyro

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Re: HDMI Surge Protection
« Reply #12 on: November 03, 2018, 10:09:16 pm »
Yes, those cases are fascinating. I have a paper copy of Wireless world from the '80/90s burried somewhere that did a fairly detailed analysis of a lightning strike on an old English church, It must be on Archive.org somewhere.  From what I remember, the lightning conductor ground point had recently been measured at around 3R to earth. When it struck, the lightning jumped from the copper down-strip something like 10-15ft to the mains wiring in the tower. Parts of the mains cabling were fine but others had evaporated in a sort of standing wave pattern. The electronic organ at the base of the tower survived with the replacement of a bridge rectifier and a couple of transistors.

On a much more modest scale we once watched a lightning tracer strike a lamp-post on the corner across the street. It took out the drive transistor for the relay coil in my work modem (yes, it was a while ago), luckily we had underground phone lines. The street lamp still wasn't working nearly a year later when we moved house though.

EDIT: I actually found the article, even if I got some of the numbers and facts completely wrong...  :-[

https://www.americanradiohistory.com/Archive-Wireless-World/80s/Wireless-World-1984-10.pdf
« Last Edit: November 03, 2018, 11:02:39 pm by Gyro »
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