The processor (and most devices like routers have one) is basically a black box which reads in a command, performs the actions the command says, goes to the next command in the sequence, and repeats. They convert it to "voltages above or below a couple of volts" to mean 1 or 0: so there's lots of leeway there. Then all the components take that 5v, and convert it into 5v and 0v to mean 1 and 0. Which means, the smoother the output is.īut there's always some fluctuation, so there's often a "voltage regulator" as the last step, a chip which takes anything from, say, 20V to 3V, and outputs a reliable 5V or so. The bigger the capacitor, the more current it can store as charge from that "lump", and the slower the discharge time is. Each voltage "lump" charges the capacitors up each dip discharges it. Then that voltage needs "smoothing": that's where the capacitors come in, and we get rid of the zero-voltage dips. So instead of waves up and down from +10 to -10, you get a series of lumps, from 0 to +10. Next step is to convert it from AC to a lumpy kind of DC: a "bridge rectifier" (four diodes arranged so that whether the voltage is flowing one way or the other on the input, it flows only one way on the output). That changes you from 110V AC to, say, 20V AC. The way this is done is first by stepping the voltage down to reasonable levels in a transformer (a couple of coils around a core: the big heavy bit in most power supplies). Obviously, then, your device must be capable of handling a /very brief/ power interruption, or it wouldn't stay on for more than a hundredth of a second. So, for a fraction of a second, 100 times a second, there's no voltage provided to your device. Most devices run from house-voltage AC (110V or 220V AC), at 50Hz or so, through a power adapter, to low-voltage DC (5V or 12V DC).ĪC current is current which cycles back and forth, from positive to negative. The "it's the capacitors" answer has already been given, but that's not the whole story. Parallel SCSI busses had this problem sometimes too. Then hit the power button on both devices. Unplug the printer, unplug the computer, and unplug the parallel cable. In fact, in the old days of parallel ports, this used to be a guaranteed way to correct a stubborn printer. This is because the button places a load on the circuit(s) holding the charge and there is no power going into the device. If the router has a button of any kind on it (WPS button, or a reset button), this will usually discharge any residual electric charge immediately. The RAM in your computer, for example, can take minutes to discharge fully.īut there is a shortcut. It's impossible to say exactly how much time is needed, as the bleed-off of that capacitance varies with environmental factors like temperature, humidity, and background EMI generated by nearby electronics. Some of this capacitance is intentional some of it is not. Ten seconds is an arbitrarily long amount of time, but yes, it does take time for electronic devices to discharge themselves completely because of the capacitance of the circuits within.
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