nilclass

@nilclass@discuss.tchncs.de

• ⁨Comment⁩ on ⁨That cereal ain't right⁩ ⁨⁨3⁩ ⁨weeks⁩ ago⁩:

  I bet that spoon has some iron

• ⁨Comment⁩ on ⁨Data is a plural⁩ ⁨⁨1⁩ ⁨month⁩ ago⁩:

  They sure is!

• ⁨Comment⁩ on ⁨The mark⁩ ⁨⁨1⁩ ⁨month⁩ ago⁩:

  That password is not very secure, you should come up with a longer one

• ⁨Comment⁩ on ⁨Is "disk" just a different spelling of "disc" or are they actually different words?⁩ ⁨⁨2⁩ ⁨months⁩ ago⁩:

  What about MiniDisc, the storage medium of the future?

• ⁨Comment⁩ on ⁨"REM sleep is the next AI"⁩ ⁨⁨2⁩ ⁨months⁩ ago⁩:

  Oh, so they can’t get autonomous driving to work, thus the next step is to get people who are sleeping to steer the cars remotely

• ⁨Comment⁩ on ⁨How do I select a transformer?⁩ ⁨⁨2⁩ ⁨months⁩ ago⁩:

  Great, good luck with that :)

  Another thing that comes to mind: for audio purposes another technique used in ring modulators for audio effects is to use a mosfet switch to mix the signal with a square wave. This has more byproducts than mixing with a pure sine, but is a lot easier to do. Since you are downconcerting, it should not matter at all if you use a square wave, since the byproducts will all be (higher-order) harmonics of the local oscillator, which you’ll filter out anyway.

• ⁨Comment⁩ on ⁨How do I select a transformer?⁩ ⁨⁨2⁩ ⁨months⁩ ago⁩:

  I’m not sure I understand what you are trying to do… do you want to build a radio? Or are all your signals in the audio range?

  Anyway:

  • w2aew has some great videos on diode ring mixers, like this one about winding the transformers: www.youtube.com/watch?v=a8ViWS61hsU
  • You can also get ready-made diode ring mixers (including transformer and everything) like this one: www.minicircuits.com/pdfs/SRA-1W+.pdf

  Regarding Gilbert cells, the two popular chips are MC1496 and SA631. The 631 comes with a built-in oscillator, so it’s quite handy. Unfortunately both are hard to come by these days.

• ⁨Comment⁩ on ⁨Centipedes Don't Fuck⁩ ⁨⁨2⁩ ⁨months⁩ ago⁩:

  Does this mean jd vance is a centipede?

• ⁨Comment⁩ on ⁨Size Comparison: Pluto and Australia⁩ ⁨⁨3⁩ ⁨months⁩ ago⁩:

  Heresy! Australia will always be a planet.

• ⁨Comment⁩ on ⁨Simple light-sensitive light switch?⁩ ⁨⁨3⁩ ⁨months⁩ ago⁩:

  Growing plants with LEDs certainly works, I’m just wondering if the power of a USB port is enough

• ⁨Comment⁩ on ⁨Simple light-sensitive light switch?⁩ ⁨⁨3⁩ ⁨months⁩ ago⁩:

  there’s no need for relays if you have low voltage

  That’s a good point. Also makes me wonder if those lights will actually make a difference when it comes to plant growth, given the low power.

• ⁨Comment⁩ on ⁨Simple light-sensitive light switch?⁩ ⁨⁨3⁩ ⁨months⁩ ago⁩:

  It’s not completely stupid. One pissible issue: when the light level is around the threshold, slight variations (think: cloud passing by) will cause the relay to switch back and forth quickly. This can be solved with some additional parts (keyword: hysteresis).

  I would recommend using a microcontroller, it makes this problem easy to solve, plus you can have more logic to trigger the lights (eg time based).

  Another thing is turning off: if it’s purely based on light level, you need to make sure the sensor does not “see” any of the LED light, otherwise it thinks the sun is back up

• ⁨Comment⁩ on ⁨Hello I think you'll love this house.⁩ ⁨⁨4⁩ ⁨months⁩ ago⁩:

  align-items: nope;
  

• ⁨Comment⁩ on ⁨Never know til you go.⁩ ⁨⁨4⁩ ⁨months⁩ ago⁩:

  That’s a common misconception. The cybertruck’s sails are designed to be pushed by a high-power stream of gasoline, not wind

• ⁨Comment⁩ on ⁨space⁩ ⁨⁨7⁩ ⁨months⁩ ago⁩:

  Is there a choice of toppings? Or do I have to think about a very specific pancake?

• ⁨Comment⁩ on ⁨What are some common misconceptions about programming that you'd like to debunk?⁩ ⁨⁨9⁩ ⁨months⁩ ago⁩:

  That sounds super familiar :D

  Anyway, a prototype is not a bad thing, if the managers know the difference. It’s easier said than done to “do it right the first time” if you don’t know how / what to build. Prototypes can be built to validate hypotheses and generally figure out what works, then build the real thing afterwards.

• ⁨Comment⁩ on ⁨I knew it all along!⁩ ⁨⁨10⁩ ⁨months⁩ ago⁩:

  I expected this to be a rickroll. Got diappointed.

• ⁨Comment⁩ on ⁨Looking for really small motors⁩ ⁨⁨1⁩ ⁨year⁩ ago⁩:

  Try searching for “coreless motor”, gives me lots of ebay results with tiny 7mm diameter dc motors looking like this: external-content.duckduckgo.com/iu/?u=https%3A%2F…

• ⁨Comment⁩ on ⁨How to improve my battery measurement circuit?⁩ ⁨⁨1⁩ ⁨year⁩ ago⁩:

  Nice, than you for sharing!

  I won’t be using this for my measurement issue (the other options are much simpler, and i was aiming for less parts, not more), but I’ll do some experiments to familiarize myself with bootstrapping

• ⁨Comment⁩ on ⁨How to improve my battery measurement circuit?⁩ ⁨⁨1⁩ ⁨year⁩ ago⁩:

  Hm, I don’t understand how this is supposed to work - is that a n-channel or p-channel FET?

  When I sketch it using falstad’s circuitjs, it looks like the FET (n-channel) is a little bit on all the time

  Image

  and fully on, when a pulse is applied

  Image

• ⁨Comment⁩ on ⁨How to improve my battery measurement circuit?⁩ ⁨⁨1⁩ ⁨year⁩ ago⁩:

  Could you do similar to diagram 2, but instead of an N-FET use a P-FET between the battery and first resistor in the potential divider?

  That’s a great idea! Unfortunately I don’t have a P-FET lying around, so cannot try it right now.

  Or use a zener/TVS diode instead of second resistor to clamp the voltage instead of dividing (more robust).

  Not sure I understand this point. Which resistor would you replace with a diode?

• ⁨Comment⁩ on ⁨How to improve my battery measurement circuit?⁩ ⁨⁨1⁩ ⁨year⁩ ago⁩:

  You could probably increase the 82K and 10K resistors to be much bigger

  That’s what I thought initially, but this stackoverflow post dissuaded me. The argument there is that the measurement will be wrong, if the input current is not enough to charge the internal cap within the measurement period. But I’ve done some testing now, and measurements done with 820k and 100k agree well with what my voltmeter measures, so I’ll go with this solution!

  a fresh alkaline 9V battery is actually 9.6V or more, not 9V.

  Indeed! 9.6V * 10k/92k = 1.04V is still below 1.1V, so I should be fine in this case :)

  9V battery voltages droop noticeably when under load because of their high internal resistance. Make sure to measure under the same conditions.

  This is a good point!

  My firmware will be pretty monotonic though, basically:

  1. wake up
  2. measure battery
  3. measure some other sensors (the actual task of the device)
  4. turn on a transceiver, send all the measurements (including battery voltage)
  5. turn off transceiver & go to sleep

  So, the load should be always the same at step (2).

• How to improve my battery measurement circuit?
  Submitted ⁨⁨1⁩ ⁨year⁩ ago⁩ to ⁨askelectronics@discuss.tchncs.de⁩ | ⁨11⁩ ⁨comments⁩
• ⁨Comment⁩ on ⁨Communication protocol suggestion for peer-to-peer device network?⁩ ⁨⁨1⁩ ⁨year⁩ ago⁩:

  You could give PJON a try github.com/gioblu/PJON