Comments by "eDoc2020" (@eDoc2020) on "JerryRigEverything" channel.

  1. In most of the US heat pumps are cheaper year-round. Here in Massachusetts (with expensive electricity) an air-air heat pump is currently cheaper than gas when it's more than 45F outside. Heat pump COP drops a bit in the cold but on modern units the capacity stays up until subzero. The heat pump I've been eyeing (Comfort-Aire VCD36) is rated 39kBtu/h@COP 3.18 when it's 47F and it drops to 32kBtu/h@COP 2 when it's 5F outside. That's not a massive drop. Single-speed R22 systems are much worse.
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  2. Air conditioning and heat pumps (more common in the South) are going to be driving up the average. Also keep in mind it's 30kWh per home, meaning more like 10kWh per person.
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  3. They should automatically defrost. If yours was freezing over it wasn't working properly.
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  4. A Game Boy runs at around 59.7 fps.
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  5.  @zack9912000  How is that the case? With inverter mini-splits you get precise temperature control everywhere. With a central system you are stuck at one thermostat temperature and in other rooms the temperature can be different.
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  6. If it couldn't clean the sensors it would need to rely on other sensors. Keep in mind this isn't a new problem. What would happen to human drivers if a window is dirty?
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  7. I presume that's just the frontend system. The actual self-driving stuff probably runs on something else.
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  8. It's stupid easy, you just need longer wires.
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  9. Here grocery stores often have collection bins for plastic bags. While they can't go in the regular stream they are still recyclable.
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  10.  @Chrislk1986  I believe many jurisdictions banned the use of single-use plastic bags in many situations. However they defined single-use based on thickness, so the stores naturally find the cheapest way to comply.
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  11. You just said why. Air conditioning and heat pumps (or even worse resistance heat) combined with poor insulation skew the average higher. There's also the fact that most Americans don't buy with efficiency in mind.
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  12. Yes. If the click comes a couple of seconds after you switch it on you are hearing a speaker protection relay. A monitor circuit ensures the amplifier is working without a DC offset before the relay connects the speakers. This stops the speakers from thumping when the amp is turned on but more importantly protects the speakers from excessive current if the circuit malfunctions.
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  13.  @lisdraw4715  Short answer is maybe. There are so many amplifier circuits around it's impossible to know without looking at the details. However, most amplifiers include temperature compensation circuitry so the audio quality difference is probably small. Amplifier biasing can be a complicated subject and I'm not an expert there.
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  14. To start with most people have refrigerators. If you have a kitchen fridge and a second garage fridge that's already close to 200 watts continuous (equivalent). Then there's stuff like cable modem/routers and TV boxes/DVRs which are probably pulling another 50W continuous combined even when not actively in use. Then things like microwave/stove clocks and other stuff drawing at least 20-30W combined in standby. That's almost 300W before you turn anything on.
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  15. The nice thing about batteries is they slowly degrade with use instead of becoming inoperable. Once a battery reaches its "end of life" metric it should still be usable, but the range will just be 70% or so what it was when new.
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  16. Yes, the relay circuits still need to be fused. I would just move the wires from the busbar to the always-on fusebox.
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  17. Unlike ICEs there is little difference in EV efficiency between running at high rpm low torque or low rpm high torque. Anything more than two gear speeds on an EV is totally wasteful.
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  18. 1. EV owners typically charge piecemeal. Fully charging from empty is quite uncommon. 2. 1940s televisions produce very sharp pictures. 3. While EVs are more toxic to produce and discard than ICE vehicles, they are much less toxic during their lifespan.
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  19. Better than recycling is reusing. In the old days (and in much of the world) we refilled glass bottles which is obviously much less energy intensive than remelting it into all-new bottles.
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  20. $707 seems pretty steep per panel. The expensive panels are around $350 each and I would guess the mounting hardware can't be much more than $100 per panel.
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  21. Regenerative brakes aren't a separate part, it's just using the drive motor differently. It's probably already enabled in the motor controller and the brake position sensor mentioned will probably go to the controller to increase regen as the pedal is pushed.
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  22. Liquid elemental mercury is actually relatively harmless to humans. What's harmful is mercury vapor or when bacteria convert elemental mercury into biosoluble forms.
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  23. Solar panels won't help too much. A typical 300w solar panel with 33% insolation will, at Zack's R1T's energy consumption of 2mi/kWh, will give you an extra 5 miles of range per day. Pulling an extra trailer will probably use more than this gain.
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  24. The plug I saw appeared to be a 30 amp RV plug. While higher current it's still only 120v.
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  25. I hope he posts a correction for this.
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  26. But how cold is your basement/garage?
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  27. The tanks are really strong. A regular automobile crash won't do anything. IIRC in Toyota's testing they needed armor-piercing missiles in order to rupture a tank.
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  28. Air to air is more efficient than air to water to radiator. Air to water to underfloor is more efficient than both but also more expensive.
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  29. You can't use Romex out in the open, only in protected areas like inside walls.
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  30. I've broken a smartphone screen twice, and neither was due to gravity-realted impacts. The first time was a junk Samsung from 2008 or so I had discontinued use of. I was taking it apart for fun and cracked the screen when trying to reseat it. The second time was in my pocket, probably keys or something else hitting just the wrong way. That sucked because I otherwise would have put the SIM card back in the crappy Samsung if I hadn't broken it.
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  31. It seems great but it's actually not worth it. Best case the panels would charge around 4 miles per hour in full sunlight. If you're traveling 50 it would make less than a ten percent difference.
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  32. If an average person drives 12,000 miles/year and an average EV uses 350Wh/mile then we can assume the car adds 4200 kWh/year.
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  33. Are you familiar with the phrase "not in my backyard"? It's literally that. Rooftops are otherwise wasted space.
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  34. Luminaires are the fixtures. Regarding the little circuit boards in CFLs, that's where I get many components as an electronic hobbyist.
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  35. On the other hand if they worked together more they would all share more bugs.
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  36.  @CodyAMason  In critical control systems they use a redundant setup with different implementations by different groups. Although I suppose if they work together each company would only need to do one.
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  37. Gauge-based systems made sense back in the day. The number was originally based on the number of times the wire would be stretched through a die in manufacturing. The higher the number, the more times it's stretched thin. While it's annoying it does make sense given the history. Well, except for the multiple zeroes. Negative numbers would be most logical.
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  38. I don't think you have 32 amps on a regular household outlet so it's still "so much power". Here in the US we use 480v and occasionally 600v if something really needs power.
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  39.  @jeffgayzose8129  I don't think it's that much more difficult. They would probably use multiple smaller packs instead of one giant one. This would afford designers more flexibility as well as make replacement more manageable.
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  40.  @jeffgayzose8129  Batteries and electric motors will never be 3x more efficient because they're already well over 75% efficient in practice. The only issue is energy density of the batteries. I don't think making the batteries removable would take up much more space. No matter what the battery needs its own (fairly) protective shell and the chassis needs provisions to hold it. To make it removable you just need to make the holder accessible without taking the machine apart. It doesn't need to be as easy to change as a power tool battery. I'm envisioning something more like how the starter battery in an ICE vehicle is held, something that may take a few minutes and even require basic tools.
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  41. The motor is probably the most reliable part in an electric vehicle. Unless it gets physically damaged the only things to wear out are the bearings, and these should be replaceable when the time comes. IMO the thing to worry about with electric vehicles is the battery.
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  42. If you need to access under the panels you must remove the panels.
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  43. Modern heat pumps can provide lots of heat below freezing temperatures. The electric heat strips shouldn't come on very often unless the unit is too small.
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