3 ms·
It means that it doesn't literally physically vibrate, like quartz oscillators do. It's only the electric field that vibrates in it, not the physical thing itse
by xyzzyz 8y ago
It means that it doesn't literally physically vibrate, like quartz oscillators do. It's only the electric field that vibrates in it, not the physical thing itself.
- ajross 8y agoI know what it means. I was pointing out (charitably) that that's a silly distinction. An electronic oscillator ABSOLUTELY vibrates "physically". Those electrons are "physical things" and have mass. They have momentum. Those things can be measured and have an impact on the circuit. Even your assumption that the transistor body doesn't move is wrong in practice. Those electric fields absolutely produce strains (that is, real physical forces) on the semiconductor junction, and those strains affect electronic properties and are included in fancy circuit models (or at least I saw a paper about it once, anyway). The idea of "solid state" machines having "no moving parts" is a lie told to you by your electronics textbooks. It's a useful abstraction. It's not the truth. And in this regime, it's frankly harmful to your understanding of how things work because it's led you to believe that crystals are doing something fundamentally different than circuits.
- gugagore 8y agoMaybe if you can show me that if you flick an RC oscillator you can detect it, then I'll believe it's a silly distinction. Or if RC oscillators can detect gravity: https://www.youtube.com/watch?v=zILwgQhjC_Q https://www.youtube.com/watch?v=zILwgQhjC_Q I'm also curious what it would mean to you for two things to be doing "fundamentally different" things. Do you believe in the difference between a mechanical oscillator and an electrical oscillator? Mechanical oscillators like a spring/mass exchange energy between kinetic and electrical energy (a moving mass and a strained material). An RC oscillator exchanges energy between elements that store energy in an electric field and a magnetic field. That feels fundamentally different even in a four-fundamental-forces kind of manner.
- hasmanean 8y agoQuartz crystals oscillate like a slab of jello vibrates. It’s not moving like a pendulum or anything...rather the bulk material is expanding and contracting and energy is stored in the deformation of the crystal lattice.
- gugagore 8y agoSame with a spring-mass oscillator, right? A spring stores energy in the deformation of materials.
- hasmanean 8y agoYes. A spring reacts to force by storing energy in the strain (aka stretching) it experiences. A crystal oscillator has the additional property that when it stretches, it develops an electric field across it--and conversely, when an electric field is applied across it, it stretches. So you can make the crystal vibrate by putting a voltage across it, and this vibration is visible when you monitor the voltage. It's like striking a bell...the bell's vibration creates an audio vibration.
- gugagore 8y agoTo be honest, I'm not really sure the reason you're explaining this. I had thought you were drawing a contrast between pendulums and quartz oscillators.