3 ms·

How the Hall Effect still reverberates

35 points by headalgorithm 5y ago

fuzzfactor 5y ago
I thought they were going to say something about the Hall Effect sensors inside the analog reverb "tanks" of the vintage guitar amplifiers.
- jmrm 5y ago
  AFAIK reverb tanks use a couple of solenoids (like a speaker or a microphone), not a Hall effect sensor[1], It won't be unusual to find some of them using Hall effect sensors, but I don't know any of them that use this technology. [1]: https://www.modelectronics.com/reverb-tanks/spring-reverbs-explained https://www.modelectronics.com/reverb-tanks/spring-reverbs-e...
  - fuzzfactor 5y ago
    Nice link. These guys make great tanks: >In the spring tank there is a second transducer at the opposite end of the spring that you can think of as the ear in a room. Instead of a signal coming in to manipulate the springs through this transducer, it works in the exact opposite way. The wave passed through the spring from the first transducer affects the magnet suspended in the gap of the second transducer. The moving field of this magnet interacts with the coil of the transducer to create an electric signal that is carried through the wires to the RCA jack labeled OUT. Not much differently than a magnetic guitar pickup or a crankshaft position sensor which are all properly included as Hall sensors. Interestingly, the reverb input transducer is the one acting like a solenoid and the output transducer is employed as the Hall sensor. And I'm sure you see how both transducers are built very similarly and look almost identical. Different impedances in the windings of their coils though.
ncmncm 5y ago
I was impressed that Tsiolkovsky knew about Hall-effect ion propulsion.
hermitdev 5y ago
Doesn't the problem still remain, though, that you're still expelling something from your spacecraft. Sure, it may be more efficient that a chemical rocket, but are we not still in the conundrum of you have to carry the stuff you're going to expel from your craft to get motive? The article mentions moving a 2600 kg craft with the force of about the weight of 5 quarters, but how much mass of the fuel is expelled to attain that force? How long can that 5-quarter burn last before running out of fuel? Space is pretty empty, but not entirely so, right? Would it be possible to somehow gather the stray atoms & dust that's in a craft's path to "top off the tank"? I know I'm straying into science-fiction area here, but yeah, basically a fuel scoop you might see in say, Elite: Dangerous or Star Gate: Universe (but probably without the part of basically flying into the atmosphere of a star).
- zardo 5y ago
  >but how much mass of the fuel is expelled to attain that force? (Force of five quarters at 1g)/(exhaust velocity) = (mass flow rate of propellent)

35 points by headalgorithm 5y ago

I thought they were going to say something about the Hall Effect sensors inside the analog reverb "tanks" of the vintage guitar amplifiers.

jmrm 5y ago
AFAIK reverb tanks use a couple of solenoids (like a speaker or a microphone), not a Hall effect sensor[1], It won't be unusual to find some of them using Hall effect sensors, but I don't know any of them that use this technology. [1]: https://www.modelectronics.com/reverb-tanks/spring-reverbs-explained https://www.modelectronics.com/reverb-tanks/spring-reverbs-e...
- fuzzfactor 5y ago
  Nice link. These guys make great tanks: >In the spring tank there is a second transducer at the opposite end of the spring that you can think of as the ear in a room. Instead of a signal coming in to manipulate the springs through this transducer, it works in the exact opposite way. The wave passed through the spring from the first transducer affects the magnet suspended in the gap of the second transducer. The moving field of this magnet interacts with the coil of the transducer to create an electric signal that is carried through the wires to the RCA jack labeled OUT. Not much differently than a magnetic guitar pickup or a crankshaft position sensor which are all properly included as Hall sensors. Interestingly, the reverb input transducer is the one acting like a solenoid and the output transducer is employed as the Hall sensor. And I'm sure you see how both transducers are built very similarly and look almost identical. Different impedances in the windings of their coils though.

ncmncm 5y ago

I was impressed that Tsiolkovsky knew about Hall-effect ion propulsion.

hermitdev 5y ago

Doesn't the problem still remain, though, that you're still expelling something from your spacecraft. Sure, it may be more efficient that a chemical rocket, but are we not still in the conundrum of you have to carry the stuff you're going to expel from your craft to get motive? The article mentions moving a 2600 kg craft with the force of about the weight of 5 quarters, but how much mass of the fuel is expelled to attain that force? How long can that 5-quarter burn last before running out of fuel? Space is pretty empty, but not entirely so, right? Would it be possible to somehow gather the stray atoms & dust that's in a craft's path to "top off the tank"? I know I'm straying into science-fiction area here, but yeah, basically a fuel scoop you might see in say, Elite: Dangerous or Star Gate: Universe (but probably without the part of basically flying into the atmosphere of a star).

zardo 5y ago
>but how much mass of the fuel is expelled to attain that force? (Force of five quarters at 1g)/(exhaust velocity) = (mass flow rate of propellent)