Especially true for LEDs, tried that in the lab once with a flood light, got a few μA out of the LED shortened with the multimeter. Did that with 8th graders, we did other experiments mainly with pv, LEDs and bipolar transistors as well.
The logical question came up more than once: “can we use photovoltaic cells as a light?“. Pretty sure that‘ll work, too, but didn’t try because stuff was expensive then and we didn’t have any broken parts of cells at the time. They probably learned a few things on that day.
Same force, not same pressure. The nozzles are relatively small.
I wouldn't want to try to intuit what the force distribution would be and how much is carried through each component of the structure, though — that's what simulations are for.
Why not? If your starting point is completely static compared to the point mass and your aspect area isn’t zero, you’re going to fall directly down towards the point mass and are going to hit it.
If it was a point mass, and you had exactly zero horizontal motion relative to it, you'd go right through and out the other side.
Well, except for relativity turning it into a black hole with a Schwarzschild radius of 8.87 mm so it won't be "point-like".
But most of the disintegrate sheen of plasma that used to be your body would have had some horizontal motion compared to it, even if only due to you starting off as an extended body.
Can relate with the learning part as the motivator. I would like to know whether you needed anything special for building the kit like e.g. an oscilloscope or other expensive instruments?
A good soldering iron, a magnifying glass (I have an articulating lamp with a built-in magnifying glass) and a basic multimeter is all that’s needed, but a clamp or “helping hands” to hold the circuit board would be helpful.
How does the device detect very short bursts? After looking up the data sheet of the RF detector I believe you would need additional circuitry to not risk that very short bursts slip through the sampling of the ESP A/D input.
While researching for parts, I also found this one: https://www.amazon.com/dp/B07RR86PFC/
It goes up to 10GHz, and it operates on 5V. Would that also be an option, and possibly allow to get rid of the boost converter too?
Thanks OP. The detector itself has a Pulse response time of 6 ns/10 ns (fall/rise) but of course the whole system will always be slower. 1 s is a lot though, got probably nothing to do with the sampling done by the esp.
Pictures are always taken from a very low angle and make it look much larger than it is. Behind the electronics area there is the riverbed. When you look at the picture, you might think the „dump site“ goes on and on. It doesn’t.
Trust me, I visited the place in 2014. Of course I had read about the place before. When I got out of the car, first impression was that our driver didn’t bring us to the right spot. It is not that big actually. The waste was mostly domestic then, judging from what I saw (CRTs for example).
Agbogbloshie is so much more than the processing of e-waste. Think of it as a commercial area. There was a large market for onions and other products. There were workshops where people build gas stoves out of car rims. Dismantling cars was big business. There was a Coca Cola Factory on the other side of the road. The air quality was really bad but it was mainly caused by burning tires, not cables. You cannot have tires sitting around there because they will always catch water (in any orientation) and therefore be a breeding bed for anopheles, which is the vector for malaria as you may be aware of.
Over all, the people who worked with electronics, not only the scrapers but also the people who actually repair and sell things, where only a fraction of the people living, working and trading goods there.
It might look different today. Government cleaned the riverbed at least once in order to prevent floorings. There were also attempts to move the onion market. Don’t know if that really happened. I am not saying everything was fine there. Working with e-waste is dangerous. There are unhealthy levels of lead and other things in the soil and in the people. But there was neither the infrastructure nor the workers to process significant loads of foreign e-waste. Even 15,000 tons per year (figures thrown around then in western media where an order of magnitude higher) is two heavy trucks per day.
I will post a few other sources later but have to sleep now. But check this out:
The logical question came up more than once: “can we use photovoltaic cells as a light?“. Pretty sure that‘ll work, too, but didn’t try because stuff was expensive then and we didn’t have any broken parts of cells at the time. They probably learned a few things on that day.
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