Thread: Ground loop

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  1. #11  
    Senior Member shijan's Avatar
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    Interesting... Seems that HDMI Surge Protector may have some diodes based component inside https://www.alibaba.com/product-deta...037447898.html Diodes just protect from electricity streams backwards.


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  2. #12  
    Senior Member shijan's Avatar
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    Texas Instruments makes similar diode based parts as well.
    HDMI Transmitter Port Protection and Interface Device http://www.ti.com/product/TPD12S521#

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  3. #13  
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    Quote Originally Posted by shijan View Post
    It may be not due regulated power, but due lower voltage output (usually regulated outputs are 7.4V or 12V). 14.8V is rather high voltage, some people even can start to feel 14-16V by fingers. So it may be more risky for electronics chips if some voltage leak appears.
    My lay understanding is that "regulated" power really means protected power. For example, there's electronic fuses on the wooden camera power distro, you can manually select their tripping current .

    In the end, I've operated for many years with many users with lots of differing accessories and never once blown a port. I'm putting this down to having the power supply system that I'm using protecting me.

    JB
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  4. #14  
    Senior Member shijan's Avatar
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    Interesting, i never thinking about voltage regulators from this point of view. So there are different types of "regulated" power exists. Sure it is possible to manipulate and lower voltage in some range with Resistors and also add capacitor to smooth electric splashes. Resistors usually overheat a lot so probably this method usable only for low wattage devices. I am also not too too big expert when it goes to electricity circuits, but i think that from some point of view HDMI Surge Protector may help. in perfect world that HDMI Surge Protector chip should be installed in camera PCB itself by default, but seems Blackmagic don't do it due economy reasons.
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  5. #15  
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    Quote Originally Posted by shijan View Post
    Surge Protector chip should be installed in camera PCB itself by default, but seems Blackmagic don't do it due economy reasons.
    I think the issue is that it affects the signal. I feel like I'm vaguely remembering this from when this was happening on SDI ports and the problem is that the ESP would mean the connector couldn't be working as a 12G anymore, it dramatically reduces the spec.

    JB
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  6. #16  
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    Seems plausible to me. A diode is, among other factors, to some degree a capacitor too.
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  7. #17  
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    Quote Originally Posted by shijan View Post
    Diodes just protect from electricity streams backwards.
    they can do a fair bit more than that depending on the diode and how the are combined in a circuit - eg a zener diode is commonly used to stabilise an output voltage over a large range of input voltages:

    https://www.electronics-tutorials.ws/diode/diode_7.html

    however I think John is fundamentally correct in that the issue with 'regulating' signals is that you then interfere with or risk degrading the signal istelf
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  8. #18  
    Senior Member Asyndeton's Avatar
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    Hm, that would probably explain why one of the SDI ports on my Ursa Mini 4K no longer works..
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  9. #19  
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    Quote Originally Posted by Asyndeton View Post
    Hm, that would probably explain why one of the SDI ports on my Ursa Mini 4K no longer works..
    Most common scenario is having two devices powered from the same battery then connecting those devices together via the SDI. Tilta battery plates seemed to also be a big culprit for a while. I think lately I haven't seen many issues being reported.

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