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Posts by bsimpsen

This makes sense. If the conversion rate is low, you'd end up with a significant number of used phones you'd have to sell as refurbs. By recycling demo phones you insulate yourself from some of that.
It seems to me the same argument could be made about the liability of gun manufacturers. Certainly they've been warned that terrorists might use their products.
I would love to sit on on a conversation between Cook and Carter.
Texas Instruments makes boost converters that run down to 0.3V (TPS61200). They power themselves from the output voltage. And they'll start up from as little as 0.5V. Bipolar transistors do have the 0.7V limitation you mention, but very few things use bipolar transistors these days. That TI boost converter is MOSFET based. You can make MOSFETs that operate (not terribly well) on as little as a few millivolts. Advanced Linear Devices makes such Zero Threshold MOSFETs and TI...
It's more or less as you say. For very low power devices, the energy consumed by the booster circuit will more than offset any additional capacity obtained from the waning battery. My smoke detectors can run several years on a 9V battery (six AAAA cells). I don't know of any boost converter than can do that, even when supplying NO power. And imagine using these things in a smoke detector. Rather than get the low battery "chirp-chirp", it will happily stay silent until the...
The discharge of alkaline batteries produces water at the anode (+, the steel case) and hydrogen at the cathode (-, the steel bottom). We know what alkaline water does to steel. The deeper the discharge, the more the corrosion. And the hydrogen gas provides enough pressure to push the alkaline liquid through the first gap or pinhole that develops (usually around the bottom seal). The alkaline liquid continues corroding your precious device until all the water available...
Nobody in their right mind designs a AA powered product that cuts out at 1.35V. That's above the fully charged voltage of both NiMH and NiCd batteries (nominally around 1.25V from 100% to 80% full charge). I generally design for warning at 1V and cutoff at 0.9. There's not a lot of energy left in an alkaline battery below 1V (<10%), let alone 0.9V(<5%).   My Magic Mouse posted a low battery warning last week and is still running fine. I just measured cell voltages of...
My claiming it's a hoax is not extraordinary and so no extraordinary evidence is required. As I said, a modest knowledge of chemistry and physics is sufficient to debunk their claim. I'm not obligated to provide that modest knowledge, though I will recommend you Google "solar insolation" to get an idea how much solar energy is available at the ground, "photosynthetic efficiency" to see how good plants are at using it and "photovoltaic efficiency" to see how good humans are...
I wonder if you're missing the point. It's not that the focus is on one wearer (me, me me!), it's the the drone is able to track something without human intervention. Tracking shots have historically required considerable effort. Before drones, they required a dolly grip and photographer. With drones, they require either a skilled pilot/cinematographer who can fly the drone and track the shot, or two people, one to pilot, one to track. With this drone, you're able to get...
Figure 1000w/m2 at noon on a sunny day. We already know how to harvest in excess of 20% of that via photovoltaics. Photosynthesis is not nearly that efficient (around 5%). Energy not converted by the plant is lost as heat and reflected/fluoresced light. You can't recover that from the ground. Any plant material in the ground is there as a result of photosynthesis (energy used to create biomass), so you can't tap inefficiencies there, they've already been spent making the...
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