The Etherkiller (2002)
fiftythree.org
fiftythree.org
My favorite though is the etherkiller hub, which is just diabolical.
This remind of story I heard about how to destroy a PC with Floppy/CD drive long time ago.
Grind match stick into powder carefully, mix with lipstick oil, spread to Floppy/CD and insert it into a system.
p.s: I solemnly swear that I am up to no good.
Everything.
>Does it fry the whole circuit
Yes.
BOFH says to luser "Can you hold this for a minute, here? We're looking into an intermittent connection problem. Yeah, right there, just a minute. Bzzzzzzt!"
eg, Gigabit Ethernet has no unused pins, and can still support PoE.
Here is a power supply I built that works directly with mains voltage, no transformer:
https://frammish.org/realized.png
The four diodes and large capacitor on the right are a full-bridge rectifier to provide 170V DC.
The top left PNP transistors are a current mirror which reflects the current through the LED to the right. The 1k potentiometer on the base reduces the mirrored current in order for the logic to consume less power than the load. The top left transistor is mostly responsible for the total inefficiency of the power supply, because it adds 0.7V (VBE) on top of the voltage of the load. One of the large heatsinks is connected to it.
The bottom NPN transistors are another current mirror but without a resistor. One would think you could just measure the current at the other end, so you get the opposite polarity from the start. But doing it this way makes it work properly at startup, when there is zero current.
The two transistors on the right are a constant-current source where the current is defined by the two resistors. This current and the mirrored current from the LED are connected directly together so that they fight. The node they are fighting over is connected to the gate of the bottom-left MOSFET. The MOSFET is connected to the other heatsink.
If the current through the LED is too low, the constant current source "wins", and pulls the gate voltage high, limited by the Zener diode to avoid overvolting the gate. If the current through the LED is too high, the mirrored current wins and pulls the gate low, shutting off current to the LED.
When the current is shut off, the capacitor on the left continues feeding the LED until the current drops enough for the MOSFET to turn on again.
This circuit also has a nasty tendency to get stuck in a steady state where the MOSFET is half on, causing an enormous amount of heat to be dissipated in the MOSFET and killing it. It might be possible to address this with an inductor to create oscillation and buffer current. But if I did it again, I would take another approach, and use an astable multivibrator to sample the LED current at discrete intervals instead of doing it continuously. This would allow time for the gate to settle either high or low so it doesn't get stuck in the middle.
Think about the pot, for example. If somebody built this, and stuck a normal potentiometer on the front of a box to adjust the voltage, they may not think to use a pot that has a high insulation rating between the handle and the wiper. You could get a nasty crack of line voltage DC through the pot handle via your squishy internals and down to ground.
The pictures are also a bit concerning - the big metal heatsinks are almost certainly live as transistor tabs are usually connected to one of the pins and you don't seem to have isolating washers and grommets. I wouldn't want to thread a screwdriver down between live heatsinks to get to the adjustment pot.
This sort of regulator is okay if it and everything it powers is sealed away so nobody can touch it, or if it's powered via an isolating transformer. It's an unusual configuration and it'd be unusual for people to know what must be done to be safe when building this circuit. That unusualness along with the nasty consequences of mistakes means you've got a moral obligation to take care to warn potential builders of some to these issues when presenting this circuit.
It's a completely un-annotated schematic. To build the prototype, someone has to select suitable electronics, put it together on perfboard, and last but not least strip a power-cable to have bare-ends to solder to the input of the bridge rectifier.
You really think that this person needs an additional warning about the dangers of 120V mains?
A good ethernet-enabled device should have isolation transformers (usually referred to as "magnetics"), either in the jack or as a separate component on the board.
Long story short, it's very possible that if anything, you'd only destroy the magnetics, which while labor intensive to replace (lots of pins on a large component body!), aren't particularly expensive.
So, the worst it should do is fry the network-facing side of the isolation part, and b0rk your network card.
...it looks like ethernet in particular mandates magnetic (rather than optical) isolation. So there's at least a possible mechanism for feeding too much AC power across the isolator, even if I'd expect the losses from trying to stuff such a low frequency (60 Hz) thru a component designed for MHz to make it rather harmless.
I'd guess that feeding in much higher frequency power (say, around 1 MHz) would be much more likely to do interesting things than would the near-DC coming out of the wall.
Yeah, or burn the building down.
http://www.micro-examples.com/pics/094-EP2-ETHERNET-schemati...
So the part that's likely to get fried by excessive current is the isolating transformer, if mains is applied across either of the RX/TX pairs. If it's applied between one RX and one TX, then unless the insulation breaks down there is unlikely to be any current flow - and the isolation transformers are rated to 1.5kV as per the spec, so 120V or 240V won't do it. The 2kV cap for the TX ground reference also stops any current from flowing that way.
I wonder if there's market for NICs with fuses or other protective circuitry on the inputs...
The scariest situation I've been in is doing measurements on the live busbars at the entry point of a skyscraper. The electrical cabinet contained a wall full of uninsulated high-voltage gear emitting an ominous 100Hz hum, as the bus bars vibrated in the EM fields. All I could think of was "don't fall forwards".
amateurs. that is no more fun than a hammer.
what is beautiful is adding a relay triggered by data passing trhu. everything will work until one string is typed on telnet or a certain site is accessed. and more importantly, with the user in the middle of something.
that is art.