The high resistance piece of wire in incandescent light bulbs glows as a result of electrons incoming through a low resistance material being squeezed through (bombard electrons that don’t want to be moved in) the high resistance material with a certain pressure (voltage). We are using the high resistance material to usurp (convert into heat and then into light) the kinetic energy of the electrons in the low resistance material (commonly copper wire).
We do the same thing with electrical heating elements and microphones.
Are we also doing this in electrical appliances from which we don’t expect a certain “end product” (heat, light, sound)? For instance, computers. When we were still using actual physical relays to build logic gates, I can imaging electron flow being converted into the energy (eletrco magnetism?) required to actuate/move the switch inside the relay. But what about today’s transistors? The processing units inside CPUs and GPUs heat up, but that’s a side effect of something I don’t understand. We are not trying to reap that heat. We are after manipulating groups transistors into expressing boolean logic by either giving them a voltage or not.
I know very little of electricity, so please do correct any incorrect assumptions! I’m very eager to learn! 😊💡
I could add to this analogy. Yes, the wind passes from a high-pressure point to a low-pressure one but that’s just direct current. The weather can change, reversing the wind every few minutes (alternating current) and you can still harvest it with a turbine (for example, a lightbulb filament or heater lights up in either polarity) but it wouldn’t help a ship with a basic sail travel to a destination (much like DC motors, it would change direction when polarity is reversed). And then there’s sound, akin to very quick polarity changes where particles never travel very far. It doesn’t carry much energy but the waves travel faster than wind and can be modulated with a signal to carry information. Both wired and wireless electronic communication is kind of like that. (Except wireless is decoupled from the charged particles that create the waves, the disturbances in E and B fields propagate on their own without matter)
Thanks! This reminds me, I’ve just recently read about old oscillators and the cycles, periods and hertz of electric signals. In oscillators, or clocks, that are used in computers, the signal switches between current - no current. Which isn’t the same as switching polarity in AC, but still.
It also reminded me of how insane I find it, that the membranes of speakers - whose vibration is controlled by an electromagnet, if I understand them correctly - are able to vibrate in a fashion that not only makes one sinus wave of one frequency, but sometimes a complex, intricate mixture of sounds, such as when watching a scene from a movie that has soundtrack, ambient sound, speech, explosions, whathaveyou. How on earth can one membrane do that… A piano commonly needs 88 keys whose combination can produce complex harmonies. Speaker membrane: hold my beer.
A piano/guitar string is plucked and then vibrates at its own natural frequency (plus in practice, higher modes aka harmonics/overtones defined by where it’s plucked and mechanical design). Wind instruments are designed to create continuous oscillation from constant flow of air by amplifying reflected waves with incoming air pressure energy (blowing straight into a cylinder won’t work, hence the weird pipe shapes, holes and reeds). Either way, they resonate at their design frequency. So do self-oscillating piezo buzzers. The speaker membrane, ideally, does not have a resonant frequency (responds equally to disturbances at any frequency between 20 Hz and 20 kHz) and needs to be pushed constantly to create sound. Like the membrane of a mechanical phonograph/turntable, the shape of the wave it should create is delivered to it in real time, except electromagnetically. That’s why player pianos need very little data (literal punch cards: one bit per beat and string (ignoring dynamics), so up to about 240 × 88 ≈ 2.6 kB per minute, uncompressed) to reproduce entire songs as opposed to audio recordings that require samples at decent precision (16 bits is generally good enough) at at least 2x the highest frequency to be reproduced (about 5 MB/min for one CD-quality channel, uncompressed).