Talk:2651: Air Gap

Worth noting that this is a large and inefficient version of an opto-isolator 108.162.221.79 05:37, 28 July 2022 (UTC)

Incandescent light bulb (assuming it the lamp does not use LED in the shape of light bulb) is not only less efficient than diode, but also much slower to warm up and cool down - it usually is much more sensitive to rapid switching, and has shorter life counted in the number of on/off cycles. --JakubNarebski (talk) 07:45, 28 July 2022 (UTC)

There’s not even any indication that the bulb is shaped like an incandescent bulb. Only that the front of the light (either fixture or bulb) is a convex curve. For all we know that could be a lens or diffuser in front of a flat LED. Whoever wrote that needs to go back and walk, because the claim that an incandescent bulb is depicted is quite simply false.172.71.142.89 10:35, 28 July 2022 (UTC)

I don't think it's less or more efficient than an opto-isolator, it essentially is just an opto-isolator. But an opto-isolator isn't supposed to be energy efficient to begin with; it's only designed to transmit data between circuits, not power. So the output side only needs to generate enough voltage/current to change the state of a transistor, and the input side only needs to generate enough light for the output side to do that. The voltages and currents involved aren't comparable to power circuits. --NeatNit (talk) 08:14, 28 July 2022 (UTC)

By the way, wikipedia links can be written like this: [[wikipedia:opto-isolator|]] result: opto-isolator (the final | automatically gets expanded to the article title without the wikipedia: prefix). --NeatNit (talk) 08:26, 28 July 2022 (UTC)

Or more often here on ExplainXkcd, {{w|article}} or {{w|article|anchor text}}. 172.70.206.213 08:35, 28 July 2022 (UTC)

It is missing that air-gapping the power supply would protect your home from voltage surges in the power network caused by lightning strikes. Depending where the lightning hits the power network, there may be no fuses protecting your home or single fuses may fail to protect you. --172.70.246.115 07:57, 28 July 2022 (UTC)

That is true. But the suggestion that this might have anything to do with general energy security (as is currently very prominent in the explanation) is entirely unconvincing to me.

Incandescent light bulbs convert most of their energy to infrared light. There are solar cells that work in this infrared spectrum, so this might not be all that inefficient as stated. This should in fact be a lot more efficient than any LED+visible spectrum based panel, as incandescent bulbs are very efficient in converting electricity into infrared light, much more than LEDs most likely will ever be. The (mostly) omnidirectionality of the light source might be an even bigger loss, as most of the light (however efficient) does not even reach the panel. And regarding sending data over this construct: As soon as there's a 0V state (which will be the case as soon as the transmission starts, due to some form of manchester coding, regardless of it being a 0 or 1 bit) the PC behind the solar panel would not only have a data transmission problem :) (With incandescent bulb, that is. A LED 0V might be short enough for capacitors in the PC's power supply to buffer it, if it is only at 50%(+PSU conversion loss) load max, as manchester coded signals per definition have a duty cycle of 50% to keep the DC bias at 0V) 172.68.51.204 08:26, 28 July 2022 (UTC)